DEPARTMENT T OF AGRICULTURE SCIENCE SERVICE-DIVISION OF FOREST BIOLOGY

Vol. 9 Jan.-Feb. REPORT BI-MONTHLY PROGRESS REPORT 1953 Number 1 Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

CURRENT ACTIVITIES

MARITIME . PROVINCES Table 1 is a list of per cent survival for the groups and shows that survival was less in the treated groups of (a) and White Pine Blister Rust on Ribes in Nova Scotia.— (b) than in the untreated groups (c). While the differences To determine the incidence of Ribes (currants and goose- are not large in terms of control effectiveness, variance berries) in southern Nova Scotia, a 560-acre block, containing analysis of the data indicates that significance is strong for white pine sites typical of the region, was marked out in an differences between treated and untreated groups, moderate 80- by 70-chain rectangle and utilized as a study area. between groups exposed to sprayed foliage in different ways, Employing the parallel strip method (strips 1 chain to but non-significant between untreated groups and those l/21chains in width) the entire area was covered, grid fashion, exposed to foliage for only one hour. Survival also differs in an intensive search for Ribes. Plants when located, were significantly between days of treatment. However, the eradicated by hand pulling, identified as to species, and similarity in trend between treated and untreated groups checked for degree of infection. suggests the influence of varying rearing conditions or other INCIDENCE OF RIBES environmental factors such as size of larvae rather than a regression of survival on time of treatment. Percentage of Total Infected The fact that survival in groups of larvae exposed to Species Total Grand Total No. % treatment (b) did not differ significantly from that of untreated groups, indicates that contact effects of the residual Ribes glandulosum Grauer 156 65 56 36 spray had little influence. Larvae reared to the adult stage on sprayed foliage were exposed to both residual contact and Ribes hirtellum Michx 41 17 24 59 stomach effects. Since survival in these groups was only half Ribes sativum Syme 44 18 1 2 that of untreated groups, it is concluded that stomach effects 241 100 81 34 were more important. TABLE 1.—PER CENT SURVIVAL OF SPRUCE BUDWORM LARVAE REARED ON FOLIAGE COLLECTED FROM A SPRAYED Breakdown of the information contained in the above AREA, AND ON UNSPRAYED FOLIAGE table disclosed an average of 0 . 4 Ribes plants per acre, of which the average infection rate was 04 plants per acre. (a) Treatments (e) Without exception, both R. hirtellum and R. glandulosum Days after Reared on Reared on were found regularly in similar sites, i.e., dense wet alder spraying sprayed One Î our on unsprayed foliage sprayed thickets with plants growing most abundantly around old foliage foliage windfalls, stumps, and stream courses. An exposed out- cropping of large boulders yielded the only samples of o o 20.7 26.3 R. sativum.—W. K. McGinn. 2 24.0 36.7 28.0 5 11.5 23.6 68.0 Larval Mortality Following Spruce Budworm Spraying. 8 52.0 63.4 69-7 —One of the methods used to assess larval mortality following 12 52.0 68.0 66.4 the 1952 forest spraying operation in the Southeast Upsal- 17 16.4 28.5 47.6 quitch Watershed, New Brunswick, was by daily counts of Mean 26.0 40.2 51.0 larvae falling on cloth trays of specific dimensions placed beneath suitable sample trees. The counts may also be analysed to show the rate at which mortality occurred. —F. E. Webb. Rate of drop was highest during the first day following QUEBEC spraying, continued high the second day, and dropped o ff Application of DDT to Control the Spruce Budworm.- rapidly thereafter. Eighty-five per cent of the drop occurred In the Spring of 1952, the Canadian International Paper within three days, 98 per cent within a week. A few larvae Company sprayed an area of approximately 8,000 acres at the continued to drop for as long as two weeks. Caseault Forest Reserve, Causapscal Lake, to control a n. Most of the sprayed area received more than one spray incipient outbreak of the spruce budworm. The Company application, through drift. "Knock-down" effects were organized and carried out this whole spraying operation, and apparent after each application in stands receiving three also took the responsibility of checking spray coverage. The successive dosages. There is no definite evidence that co-operation of the newly established Forest Entomological successive sprayings resulting from drift increased the total Laboratory of the Division of Forest Biology and of the eventual kill, but they undoubtedly contributed to efficiency Bureau of Entomology of the Quebec Department of Lands of control and hastened the rate of mortality. They may and Forests was requested to determine the effects of the help to explain the high percentages of control (99 to 100 insecticide on the budworm population. per cent). It has been suggested that an equal kill could be The forests on the Reserve are predominantly composed obtained by doubling the distance between flight lines and of balsam fir, distributed in a series of well defined and spraying the area twice. This would have the advantage of seperate stands, most of them averaging 7 . 3 inches D.B.H. completing the first application in time to protect the new with other younger trees. Surveys made prior to the spraying foliage. indicated that young trees were practically free from budworm Rate of mortality appears to have been slightly more attack and that the infestation on the older trees was light rapid on later sprayed areas, probably due to the greater to medium, with an average total defoliation of 11 . 2 per exposure of the larvae. No significant differences in rate of cent. Sampling during the active larval period showed a mortality can be detected on areas receiving different dosages. mean population of 2,965 larvae on larger trees in the most Methods of spray assessment used were inadequate to measure severely affected areas. dosage efficiency under the prevailing conditions. Spraying was done during the month of June, with one The data reveal nothing about the causes and nature of Beaver plane equipped with spray booms. The spray, con- delayed mortality. Experiments to test the residual effects of sisting of one pound of DDT per U.S. gallon of a pro- the insecticide were made on groups of larvae collected prietary solvent, was applied at the rate of one gallon per periodically from unsprayed areas. These were reared to the acre. Distribution of spray was checked with dyed papers adult stage under three conditions: (a) on sprayed foliage; which were distributed at convenient places along lines (b) on unsprayed foliage after being forced to crawl over throughout the area to be sprayed. The intensity of spray sprayed foliage for one hour; (c) on unsprayed foliage deposits was estimated by comparison with known standard (control). The sprayed foliage was obtained from a balsam papers prepared by Mr. K. R. Elliott. Records showed con- fir tree sprayed on June 25, which received a spray dosage tinuous spray deposits, but the amount varied considerably of 0 . 6 gallon per acre, assessed at ground level. from one place to another. 64018-1 Most of the areas were sprayed when 48 per cent of the In a previous article (Bi-Monthly Progress Report Vol. 8, larvae were in the fourth instar, 43 per cent in the fifth, and No. 6), it was pointed out that the genera Beauveria and only 6 per cent in the sixth. At the time of the last spraying, Tritirachium can be differentiated on the basis of morpho- at the end of June, 66 per cent of the larvae had reached logical characters; they are also differentiated biologically in the sixth instar, and 33 per cent were still in the fifth. that Beauveria spp. are primarily parasites, whereas Tritira- Two methods were used to check mortality caused by the chium spp. are primarily saprophytes.—D. M. MacLeod. insecticide. One consisted in sampling budworm populations White Pine Blister Rust Reconnaissance Surveys, 1952. at regular intervals in. 18 sampling stations selected as —During the past year reconnaissance surveys were conducted uniformly as possible throughout the area to be sprayed, and for the purpose of assessing white pine blister rust conditions in two check stations having similar characteristics, but suffi- in various parts of Ontario, and demonstrating progress of the ciently far from the sprayed area to avoid contamination due disease, if any, during the interval since the last assessment. to drifting spray. Three 18-inch twigs were cut o ff from each The principal findings were as follows: of eight previously marked trees providing a total of 24 twigs In Norfolk County, in natural woodlands remote from from each station. influence of cultivated Ribes bushes, blister rust infection of In the other method, mortality results were measured by pine remained at a low level of about 1 per cent. Thus no collecting larvae falling on a collecting sheet placed beneath change has occurred there in the last 10 years. The small the sample trees. A total of 52 trees were used, 47 distrib- number of Ribes plants found in the woods is evidently not uted over the area to be sprayed, and 5 used as a check. enough to induce an important amount of rusting of pine, Larval drop was determined daily starting a few days before under the conditions in which it is growing. spray was applied, and continued until all the larvae had In the vicinity of Lost Channel, Pickerel River, District ceased falling. The trees were then felled on large cloth of Parry Sound, the number of infected pines has increased sheets, and one-fourth of the foliage examined carefully to threefold in the last 13 years. Current infection amounts to check the possible recovery of surviving larvae and the 16 per cent of the whole, and approximately one-quarter of residual mortality. the larger trees. Mortality is still only about 3 per cent. Despite irregular spraying, results were fairly uniform, In Boulter Township, District of Nipissing, in pine averaging 99 . 3 per cent mortality with the twig-sampling reproduction up to 25 or 30 years old, the amount of infection method, compared with 97 . 2 per cent for the larval-drop has increased approximately fourfold since 1939. One-quarter method. No consistent relationship could be detected of the larger trees, now of sapling size, are diseased. Surveys between the quantity of DDT reaching the ground in different conducted in the fall of 1952 in northern Ontario, indicated places, and budworm mortality. On trees used as control, that a low level of infection exists at localities where young natural mortality of the larvae averaged 25 . 6 per cent.— timber stands are still undisturbed. At Obabika Lake and in Lionel Daviault. the Mississagi River Valley, less than 3 per cent of the trees were diseased. However, on cut-over areas in Temagami, in ONTARIO Olive and adjacent townships, the development of rust was much further advanced. There, about 15 per cent of all The Virulence of the Parasitic Fungi Beauveria spp.- white pines were infected. This surprising condition is per- In nature, representatives of the genus Beauveria are a con- haps the result of accelerated Ribes growth following cutting tinuous factor in the natural control of many insect pests. It and other disturbances in the woods some time ago. does not appear, however, that the mortality caused by this At localities near Lake Panache and Washagami Lake, fungus is as great as that suggested in published investiga- District of Sudbury, under conditions believed to favour rust tions. In many reported cases, the high mortality is believed development, less than 10 per cent of the trees in young to have been due to the rearing of field collected material in timber stands were infected, and mortality was still very low. the laboratory. Under such conditions insects are much more —W. R. Haddow. subject to Beauveria infection than in their natural environ- ment. PRAIRIE PROVINCES In this investigation, Beauveria bassiana strains were Predation of Larch Sawfly by Birds. —In early August, isolated from 63 different insect species from several families 1952, observations were made on birds feeding in a tamarack of Orthoptera, Coleoptera, Lepidoptera, and Hymenoptera. bog in the Whiteshell Forest Reserve, Manitoba. The site Infected material was collected throughout Canada with the has been described in a previous report (Bi-Monthly Progress exception of Prince Edward Island and Newfoundland. It is Report, Vol. 8, No. 5). The most startling observation was believed, however, that Beauveria strains are associated with made in the late afternoon of August 5, when a flock of nine insect species in these areas as well. Infected insects were evening grosbeaks invaded the bog and began feeding upon also received from different parts of the United States and larch sawfly larvae. The entire flock settled on one tree and Europe. the individuals would consume whole clusters of fifth-instar larvae before moving to another branch. The flock visited In some instances the material examined from various insect four trees within approximately ten minutes before flying out species did not include more than two or three specimens. of range of observation. Flocks of warblers, mostly immature, It was not possible, therefore, in such cases to make any invaded the bog for about two hours each morning and reference to the importance of Beauveria strains in their evening during the week in which observations were made. natural control. Where a large number of a particular insect The following birds were observed feeding on larch sawfly species was examined, e.g. Carpocapsa pomonella L. Choris- larvae: black and white warbler, Blackburnian warbler, chest- toneura fumiferana (Clem.), Pristiphora erichsonii (Htg.), the nut-sided warbler, Canada warbler, and red-eyed vireo. Three number naturally infected with Beauveria strains varied from additional species were observed feeding sporadically, presum- 0 . 5 to 13 . 1 per cent. ably on larch sawfly larvae. These were the bay-breasted Under laboratory conditions, a heavy mortality generally warbler, the robin, and the Lincoln's sparrow. No attempt develops within a period of six to ten days when spores of was made to determine the number of larvae destroyed, nor B. bassiana are sprayed or dusted on larvae of P. erichsonii, the number of birds involved.—C. H. Buckner. C. fumiferana, C. pomonella, Malacosoma disstria Hbn. and Central International Forest Insect and Disease Confer- Diprion hercyniae (Htg.). Under field conditions, however, ence.—For some years the need has been felt for an organiza- the artificial dissemination of spores on feeding P. erichsonii tion of forest entomologists and pathologists in the central larvae did not bring about a significant increase in the Canadian Provinces and the Lake States. Following a incidence of Beauveria infection. More promising results preliminary meeting in December, 1952, attended by a few were obtained when the spores were applied as a ground representatives, the organizing meeting and first annual con- spray just before the larvae dropped to the ground to form ference were held in St. Paul, Minnesota, January 6-7, 1953. cocoons. The principal items in the extremely brief and simple Within the infected host insect the fungus generally forms "constitution" are, in effect: (1) Name, as above. (2) Purpose, a hard compact sclerotium, the external chitinous covering to provide a meeting ground for discussion of the technical being the only part that does not appear to be infected. aspects of forest pathology and entomology in the general Shortly after the mummified larvae are placed in a sterile region that includes, Saskatchewan, Manitoba, Ontario, Minne- moist chamber at room temperature, the fungus begins to sota, Wisconsin, and Michigan. (3) An annual conference will protrude, at first from the intersegmental areas and then all be held. (4) The elected executive consists of only the over the body of the insect, completely enveloping it with a Chairman who will be responsible for organizing the annual white coating of mycelium. meeting to be held in the year of his tenure of office. Although Beauveria develops primarily on insects, isolated An important feature of the new organization is its cases have been reported where Beauveria strains were isolated restricted regional application which is intended to facilitate from humans, guinea pigs, and rodents; their role in each attendance by a large proportion of interested individuals case for the most part was uncertain. The fungus does not rather than by relatively few representatives as in the case appear to attack plants or develop as an ordinary saprophyte. of large national conventions. A second feature which is The fact that the conditions which determine the occur- stressed is informality in order to encourage participation by rence and extent of the disease are not well known emphasizes all interested persons. About 60 persons attended the first the necessity for more complete ecological and physiological convention, and there was general agreement that the discus- studies of the organisms and their insect hosts. sions and exchange of ideas fully justified the occasion. It was decided to hold the next conference at Sault Ste. Marie, Ontario, in October, 1953. Dr. B. M. McGugan is Initial pH at Culture growth' optima After 10 days Chairman for this year.-C. G. Riley. After 7 days Coccinellid Predators of Scale Insects.-In September, 1952, a roadside planting of elm in Regina was examined to North American No. 1 - 4.6 5.52 5.96 " No.2 4.95 4.6 5.52 determine the degree of infestation by the European fruit " No.3 4.6 4.6 lecanium, Lecanium corni Bouché. The planting was one mile European No. 4 4.6 4.95 long, two rows wide, and contained approximately 260 trees " No.5 4.6 5.52 5.5 10 to 12 feet in height. The trees were in poor condition and " No.6 4.95 4.95 many of the leaves were heavily infested with Eriophyes mites. The population of L. corni had declined appreciably since it 1 Growth is estimated on the basis of the average colony diameter of three was last examined in 1950. This decline was probably due to replicates. the feeding of large numbers of coccinellid predators. The 2 Double growth optima. temperature at the time of examination was approximately A quantitative analysis of cellulose decomposition and 55° F., and most of the beetles were clustered on the sunny cell synthesis of three North American and three European side of the trunks. The species present were: Coccinelle cultures of this fungus, cultivated in a synthetic salt solution transversoguttata Fald., Hippodamia convergens Guer., Hippo- with filter paper as a source of carbon, was undertaken to damia tridecimpunctata L., and Chilocorus stigma Say. The determine the relative efficiency in utilization of this sub- elytra of many of the C. transversoguttata and H. tridecim- strate by cultures from each group under varying conditions of punctata were withered and discoloured; laboratory examina- pH and temperature. This experiment was designed on a tion disclosed that these beetles were infected with a fungus, factorial plan and the analytical data treated statistically by Fusarium sp.-C. E. Brown. an analysis of variance. Results so far obtained demonstrate highly significant differences amongst European and North ROCKY MOUNTAIN REGION American cultures, but do not indicate that any significant response variation, under the conditions of this experiment, Comparative Studies of North American and European occurs between the two groups.-D. E. Etheridge. Cultures of the Root Rot Fungus Fomes annosus (Fr. Cooke.-Comparative studies of cultural and physiological Forest Insect Survey.-In 1952, a total of 2,203 samples characteristics of sixteen isolates of Fomes annosus (Fr.) Cooke were received. In addition to the general sampling, a branch- from various localities and hosts in North America and sampling technique was used to determine the status on white Europe are being conducted to discover the possible existence spruce of the populations of the black-headed budworm, of distinct European and North American forms. The scope Acleris variana (Fern.) ; the spruce budworm, Choristoneura of these investigations includes such phases as the variation fumiferana (Clem.), a spruce budworm, Zeiraphera fortunana in cultural characteristics; the relative effect of H-ion con- Kft., and the balsam-fir sawfly, Neodiprion abietis (Harr.). centration in malt agar on the radial growth rate; and the From this sampling it was noted that the species, Zeiraphera effect of H-ion concentration and temperature on the ability fortunana, was most abundant at Ferrier and Strachan in the of the different cultures to utilize cellulose for their growth. Rocky Mountain House area; the black-headed budworm was While a more critical analysis of these data is essential before most numerous at Ferrier and Strachan, at Mistaya River in it can be stated that distinct European and North American Banff National Park and at Marble Canyon in Kootenay forms of this fungus do not occur, the following general National Park; the spruce budworm was most prevalent in observations indicate that no consistent differences are to be Banff, Yoho, and Kootenay National Parks; the balsam-fir found between the two groups. sawfly occurred in greatest numbers along the Belly River in Studies of four North American and twelve European Waterton Lakes National Park. All branch samples were cultures grown in Petri dishes were conducted over a period made between June 21 and July 21. A table with the results of five months. Growth data and colony characteristics were of this sampling will appear in the Annual Report of the recorded after one week. The effect of sub-culturing did not Forest Insect and Disease Survey for 1952. markedly influence the growth rate, or the general appearance The infestation of the lodgepole needle miner, Recurvaria of the mycelial mat in the individual cultures, although a few milleri Busck, remained at approximately the same levels in sub-cultures of the series developed the slow-growing char- 1952 as in 1951 in Yoho and Kootenay National Parks. In acteristic of "degenerated" mycelia as defined by Roll-Hansen * Banff National Park there were heavy but patchy infestations The individual variation in growth rate and colony appearance, between the 5,000- and 6,000-foot levels of altitude. In Jasper however, was very great, with fast- and slow-growing cultures National Park there were medium to heavy infestations at occurring in both the European and North American groups. Poboktan Creek and along the Edith Cavell road. In 1952 the forest tent caterpillar, Malacosma disstria (Hbn.), infes- 50 tations occupied considerably more territory than they did in -o-AMERICAN 1951. West of Rimbey the outbreak spread south to Ferrier -6-EUROPEAN and Saunders. The infestation in the vicinity of McKay and 40 Chip Lake covered a large area; it may even extend to White- court. The outbreak near Smith decreased in intensity.- W. C. McGuffin. â 30 BRITISH COLUMBIA u Pitch Moth Infestation in Western White Pine.-During u 20- November, 1952, personnel of the Laboratory of Forest Biology, Vernon, visited a timber sale at Magna Bay, Shuswap Lake, to determine if insects were a factor in the unhealthy 4 condition of western white pine (Pinus monticola Dougl.), on 10 the area. The inspections revealed that two species of pitch moths, tentatively identified as Dioryctria zimmermani Grote and Vespamima novaroensis Hy. Edw., were present in J- epidemic proportions. It was estimated that about 50 per 3 • 4 5 cent of the stand of white pine over 6 inches d.b.h., were infested in varying degrees. The intensity of the infestation PH indicated that it extended beyond the area of the timber On 2.5 per cent malt agar adjusted to a pH range of sale (2,000 acres). 3.1 to 6.9 with a phosphate buffer, growth optima after a Spot checks along highways, logging roads, and trails period of 7 days at a temperature of 23° C. were observed at revealed a similar degree of infestation on the shores of initial pH-values 4.6 to 5.5 as shown in the accompanying Shuswap Lake, on the eastern shore of Mara Lake, at Enderby, table and graph. The direction and magnitude of the change Hupel, Lumby, and Mable Lake. The infestation was traced from the initial pH due to the metabolism of the fungus is across the Monashee Pass to Needles, Burton, Arrowpark and indicated by the horizontal arrows from the curve values. It Nakusp on Upper Arrow Lake, and New Denver and Silverton can be seen that the most favourable H-ion concentration for on Slocan Lake. Generally, from 10 to 50 per cent of the the growth of both fast- and slow-growing cultures is essen- white pine in the stands were infested but saplings were tially the same and no consistent differences are seen to occur usually attacked only when open-grown or under a light in the growth response of cultures from the European and canopy. North American groups. Consultation with pathologists of the Laboratory of Forest *Roll-Hansen, Finn. 1940. UndersØkelser over Polyporus Biology, Victoria, B.C., showed that in most cases the pitch annosus Fr. saerlig med henblikk pa dens forekomst i dat moth attacks were associated with blister rust cankers. Appar- s¢nnafjelske Norge. Norske Skogsfors¢ksv. Meddel. 7:1-100. ently, the pitch moth population built up on diseased trees to its present status where it attacks healthy trees. The pitch moth population is extremely large as indi- With the exception of viability and regional distribution, cated by the proportion of attacked trees in the stands and it is apparent from the above that no significant differences the intensity of the attacks on individual trees. Forty-five have been found to date between the sporophores of the fresh pitch nodules and approximately as many old nodules fungus on Douglas fir and P. weirii on cedar.—G. W. Wallis. were counted on one tree of 12 inches d.b.h. The moths lay their eggs on that portion of the stem Pole Blight of Western White Pine.—Of the nine fungi within the crown, all or parts of which are eventually girdled most frequently isolated in 1949 and 1950 from white pines by the larval tunnels in the cambium. As the top dies, the affected by the pole blight, only a species of Leptographium moths continue their activities in the green part of the crown. (syn. Scopularia Preuss, and Hantzschia Awd.) was found The entrance to the irregularly shaped tunnel is usually indi- capable of producing lesions similar to those associated with cated by a pitch nodule. Where trees offer little resistance to the disorder. Since that time, ten other fungi have been attack, the entrance may be indicated by the presence of tested in inoculation experiments. None of these have shown webbed larval castings. At the time of the inspections only ability to produce any of the pole blight symptoms. Although late-instar larvae were found. Leptographium sp. has been isolated more consistently from Because of the frequent association of the pitch moths lesions occurring on pole-blighted trees in the interior of with blister rust, it is difficult to separate those symptoms British Columbia, than has any other single organism, the attributable only to the attacks of the pitch moths. Infested frequency of isolation has been low. The fungus has been trees, however, generally exhibit all or some of the following isolated from only 24 of the 304 lesions sampled. The lesions symptoms: (1) yellow, sparse, stunted foliage; (2) red foliage were collected for culturing from the stems of 123 trees. Since on a section of the crown or on individual branches; (3) spike- the discovery of a disorder similar to pole blight in the coastal top; (4) pitch nodules and resinosis.—J. Walters. region of British Columbia in 1951, the fungus has been isolated from 100 of the 132 lesions on 27 trees sampled in Root Rot of Douglas Fir.—A root disease, similar to this region. yellow ring rot caused by Poria weirii Murr. on western red Inoculation experiments have been undertaken in the cedar, is causing considerable localized damage to young interior and coastal regions to determine the role played by stands of Douglas fir in British Columbia. Preliminary sporo- the Leptographium sp. in the pole blight complex. Of the phore examinations have been undertaken to ascertain the 149 trees between 40 and 100 years of age inoculated during; relationship between the two diseases. Results of these the past three years, none have developed any of the crown investigations may be summarized as follows:- symptoms attributed to pole blight. All have developed Sporophores on Douglas fir.—Fruit bodies abundant in resinosis above and below the points of inoculation, indicating the fall of occasional years on the base of logs and upturned the presence of lesions. In many cases the number of lesions stumps, not usually forming until the wood is in a final stage present as a result of inoculation was more numerous than of decay, common on the coast while sparse to absent in the that found on diseased trees. Up to this time, the short-term interior, annual, soft and pliable when fresh, rigid and fragile inoculation experiments on white pine with Leptographium when dry, separating readily from the substratum; tubes 2-6 sp. have indicated that: lesions similar to those found on mm. long; pore surface coarse to moderately smooth, deeply pole-blighted trees are produced by the fungus; trees from cracked in old specimens; pore mouths angular, thin-walled, entire, 4-6 mm.; spores smooth, hyaline, 2.4-3.4 x 4.6-5.4u; 1 to at least 175 years of age are susceptible; roots and all setae abundant, 2.7-9.3u diameter, tapering to a point, pro- parts of the stem are susceptible; trees are susceptible at all jecting up to 60u above the basidial layer. times of the year: wounding is necessary for entrance for Sporophores on western red cedar.—Fruit bodies very establishment of the fungus; individual isolates from the abundant in the interior but relatively sparse on the coast, interior and coastal regions may vary somewhat in patho- perennial up to a maximum of 15 years (commonly 6 to 8 genicity but there are no consistent differences between those years), separating readily from the substratum; tube layers from one region as compared with those from the other. 1-4 cm. thick, definite subicular mat between each layer, tubes The above isolation and inoculation studies indicate an 2-8 mm. long each season; pore surface fine, occasional deep cracks when dry, pore mouth angular, thin-walled, entire, association of the Leptographium sp. with pole blight. In the averaging 3-5 per mm.; spores smooth, hyaline, globose to light of data obtained through current studies and from subglobose when young, ellipsoid when mature, 3.0 x 5.6µ; previous analyses of affected trees, however, there is con- setae abundant, tapering to a point, projecting well above siderable doubt that this fungus is the sole cause of the the basidial layer. disorder.—A. K. Parker. CORRECTION Our attention has been drawn to an error in the article "Damage to Red Pines by the Saratoga Spittle bug" by L. A. Lyons, Vol. 8, No: 6. Sentence 1, paragraph 2, reads as follows: "Adult spittle bug feeding... results in shortened growth during year of attack and sometimes death of subsequent shoots." The author has pointed out that "Adult feeding does not result in shortened growth during the year of attack; shortened growth does not appear until two years following the year of attack". —Editor.

EDMOND CLOUTIER, C.M.G., O.A., D.S.P., Queen's Printer and Controller of Stationery, Ottawa, 1953.

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■ DEPARTMENT OF AGRICULTURE SCIENCE SERVICE-DIVISION OF FOREST BIOLOGY

Vol. 9 March-April REPORT BI-MONTHLY PROGRESS REPORT 1953 Number 2 Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

CURRENT ACTIVITIES

MARITIME PROVINC',ES 2. When the trees are too large to be completely sprayed with available equipment, satisfactory control can be Post-logging Attack by Borers and Bark Beetles on Jack obtained by thoroughly spraying the basal 8 Ito 10 feet of Pine.—A report by Mr. J. S. Prebble, Newcastle, N.B., of the tree trunks with DDT in the fall. The wingless moths injury to jack pine near the Bartibog River, N.B., was investi- are killed as they crawl over the sprayed surface before gated in December, 1952. Peeled pulpwood cuttings of jack laying their eggs in the crevices of the bark and under pine had been carried on in the area for three years, leaving a lichens on the trunks and branches. For this spray, DDT considerable number of trees for the next crop. In the late emulsion is used at the rate of 20 pounds of technical DDT summer of 1952, the crowns of many residual trees on the 1951 to 100 gallons of spray. Because of the long period over and 1952 cut-over areas turned yellowish, then red, and finally which the adults emerge, two applications of spray are brown. Similar trees were commonly present in the fringes of necessary. The first should be applied immediately after adjacent uncut areas but absent at depths of 5 to 6 chains into the first male moths are seen in flight, which is between these stands. October 25 and 31; and the second, about two weeks later. Examination of the discoloured trees showed that the bark 3 Spraying individual trees or small parts of an infested of twigs, many small branches, and often the upper 4 feet of area has very little value as reinfestation rapidly takes the main stem was badly damaged by the feeding of adult place as a result of the small larvae drifting in the air on sawyer beetles, Monochamus spp. This injury, often to the silk threads from unsprayed trees.-C. C. Smith. extent of complete girdling of the twig or branch, was no doubt the cause of death of the foliage. Trees with yellow needles QUEBEC bore numerous pitch exudations on their trunks from unsuc- The Spruce Budworm on the North Shore of the St. cessful attacks of bark beetles. Such trees had only limited Lawrence River.—The spruce budworm in this region was bark beetle damage in the cambial region. In trees with red first noticed in 1944, in a few samples collected on the to brown foliage, pitch spots were few but the cambial injury Escoumains River. The population remained at a low level was extensive. The pattern of nuptial chambers and :egg until 1948, when it suddenly increased and spread in an galleries indicated that the beetle was probably Ips pini Say. easterly direction as far as the Manicouagan River. In 1951, Recently dead trees showed considerable infestation by the population had reached considerable proportions in these secondary borers and numerous egg slits of the adult sawyers. areas. Although there was little to indicate what course the Examination of roots by a pathologist showed no evidence of outbreak would take in 1952 and following years, it was feared disease. that it might develop eventually to greater proportions and It seems probable that fresh pine slash in 1950 attracted cause considerable damage to the valuable coniferous reserves many sawyer beetles from surrounding areas. During the on the North Shore. For this reason, the forest limit holders mating period, the beetles fed on the bark of nearby trees operating in this region, were anxious that a complete and which were already temporarily weakened by exposure. Slash detailed survey should be made at once to clarify the situation. produced in 1951 set the stage for a rapid build-up of the Following a specific request, a project was elaborated in borer population. Despite apparently extensive twig girdling in early spring, and carried out during the summer. This pro- 1951 discoloration of the crowns had not been reported. This gram, which provided for intensive larval sampling, egg-mass was probably due to the modifying effects of a cool, moist sampling and damage appraisals in simple plots, involved the summer. The trees weakened by exposure were attacked both co-operation of the newly 'established Laboratory of Forest unsuccessfully and successfully by Ips. In contrast to the Zoology in Quebec City, the Bureau of Entomology of the moist conditions of 1951, the dry, hot summer of 1952 acceler- Quebec Department of Lands and Forests, and the limit ated the desiccation of girdled twigs, and the effects of the holders. build-up of the borers and bark beetles combined to make the damage more noticeable. Summary of Larval Samples The injury may be attributed to: No. Samples 1. Temporary weakening of residual trees by exposure follow- Watersheds Sampling No. Trees ing cutting, intensified by dry weather in 1952. Period Sampled Posi- Nega- With- tive tive out Total 2. Attraction of Monachamus and Ips to the cut-over areas. rec- 3. Multiplication of the borers and bark beetles in slash. ords 4. Severe injury to twigs by the feeding of Monochamus adults. Escoumains and June 19—June 26 B. Fir 34 32 2 0 5. Both unsuccessful and successful attacks by Ips, success Portneuf June 27—July 1 W. Sp. 3 2 0 37 depending on the vigour of the trees attacked. Such out- S. au Mouton and June 19—June 21 B. Fir 15 14 0 breaks are not likely to outlive the cutting operations.— Papinachois July 4— 15 J. Clark. S. au Cochon and June 5—July 4 B. Fir 53 40 11 2 Control of the Winter Moth.—The winter moth, Laval and Bersimis Bl. Sp. 1 1 o 54 Operophtera brumata Linn., is a troublesome pest of shade Aux Outardes and June 19—June 24 B Fir 61 33 22 6 trees in parts of southwestern Nova Scotia, particularly be- Manicouagan June 20—July 10 BI. Sp. 2 2 0 63 tween Halifax and Liverpool. The native fall cankerworm, Franklin and June 30—July 8 B. Fir 30 17 13 0 Alsophila pometaria Harr., which has very similar habits, is Mistassini July 1—July 7 30 generally associated with it. The possibilities of biological Aux Rochers and July 1—July 25 B. Fir 30 o 30 control are being studied but the continuance and increase Vachon of the outbreak have made spraying necessary in Liverpool, 30 Bridgewater, and Lunenburg. Experiments and spraying Trinity Bay June 30—July 9 B. Fir 13 9 4 0 13 operations have indicated the following: Pentecôte July 7—July 19 B. Fir 18 8 10 0 18 1. When proper equipment is available, the most effective control is obtained by spraying the foliage in the spring Godbout June 27—July 3 B. Fir 15 12 3 0 15 when the caterpillars are small, after the leaves have flattened out and are about 1 to 11/2 inches in length. In During the first year of work, the budworm was found the south shore areas this would be about May 25. For in all the main watersheds along the North Shore, from the foliage spraying, DDT should be used at the rate of 3 Escoumains River at the western end to the Moisie River pounds of 50 per cent wettable powder to 100 gallons of to the east. In areas where the insect was most abundant, water. its presence was easily detected with the usual standard 66421 2 sampling methods, whereas in areas where these methods 1951, when a greenhouse built for this purpose was available. failed to give positive results, it was sometimes possible to At the same time the selection of apparently healthy trees find the insect after careful examination of balsam-fir foliage. that had escaped infection in heavily diseased areas, was The following table is a summary of the results obtained undertaken. Seedlings and cuttings secured from those trees with larval sampling. in 1951 were the first materials used for experimental rooting The area where the insect was most abundant included a and inoculation techniques. A group of 118 seedlings, obtained stretch of land extending along the shore of the St. Lawrence from 14 selected trees replanted in the greenhouse during from Escoumains to Aux Anglais River approximately 40 November, 1951, were inoculated with a spore suspension of miles wide on the Escoumains watershed, and 10 miles wide Ceratostomella ulmi (Schwarz) Buis. In the middle of March, at the eastern extremity. With the exception of this stretch, 1952, less than one month after, symptoms of the disease the budworm was not very abundant, and a large number of were noticed on a proportion of 50 to 100 per cent of samples gave negative results, particularly east of Comeau inoculated individuals of each strain. This first attempt Bay. showed that resistance testing could be carried out in the Referring to total defoliation data recorded on balsam greenhouse on seedlings of less than one year and, consequent- fir, the highest plot average, 40.9 per cent, occurred on the ly, that a large number of useless and cumbersome plants Escoumains, Sault-au-Mouton and Portneuf watersheds which could soon be eliminated. Similar tests were made at the end included the areas where the budworm was first noticed on of June, on three-year-old stock from 8 different strains, and the North Shore. In this section, defoliation of some balsam- on seedlings from 12 other strains. From the positive results fir trees might be as high as 75 per cent, but such conditions obtained, it is obvious that no evidence of resistance has as were limited to small, restricted areas. yet been found, but the results of the inoculation show that a Balsam-fir top killing was also general in the above suitable testing method is being used. Other tests on watersheds. The highest plot average for top killing was resistance will be carried out next spring on cuttings collected 30.9 per cent, but no mortality could be definitely attributed in 1952 from 21 trees selected the previous year. At the end to the budworm. of the summer of 1952, trees were again selected in locations Egg-mass sampling gave surprising results; the number of high disease incidence to secure another crop of cuttings of egg-masses found was very low, and this seemed to indicate for 1953. This working procedure will be kept running until a decline in population density. Such a condition is also the discovery of a resistant strain to be used in future breeding shown by comparison of 1951 current year shoot defoliation work for new varieties. In addition to the scouting for with 1952 defoliation. Over the entire area of heavier infesta- natural immunity in native elms a program of breeding work tion, defoliation was lower in 1952 than in 1951.—René with strains from outside this Province, and with exotic Martineau. species, is under preparation. The development of elm Dutch Elm Disease Control in the Province of Quebec.— varieties resistant to this virulent disease, remains the most It has been shown by prior investigations that the Dutch Elm practical answer to the problem, and will allow the gradual disease is too firmly established in the Province of Quebec replacement of the casualties from attack by this exotic to be displaced by the eradication of centres of infection. pathogen.—René Pomerleau. With the exception of towns and cities where sanitation ONTARIO offers a fairly effective means of control, it is not possible Mortality of White Spruce, Lake Nipigon Area.— either to confine the disease to a particular area. This out- The bark beetle infestation involving mortality of white break, introduced in this country before 1944, has rapidly spruce trees in the Lake Nipigon area, described in a previous progressed and spread throughout most of the range of elm issue of this Report (Vol. 7, No. 6), was re-examined in 1952. in the Province in less than ten years. Yet, instead of Red-topped white spruce which had been prevalent over showing signs of diminishing, it is steadily increasing in a large area to the south, southwest, and west of Lake distribution and intensity. It is most important, therefore, Nipigon in 1951, occurred only rarely in 1952. This situation that efforts should be maintained towards the finding or which had been suspected from intensive ground reconnais- improvement of the most practical methods Ito control this sance during the early part of the summer, was confirmed by disease, which threatens this beautiful ornamental tree. flights over the area in early August and again in September. Sanitation, involving the quick removal of diseased trees In the aerial surveys, considerable numbers of dead trees were and the suppression of insect breeding material, is still the seen, and on checking some of these closely from the ground foundation of every control program in limited areas. How- they were found to contain new adults of the eastern spruce ever, it is generally accepted that the responsibility for sanita- bark beetle, Dendroctonus piceaperda Hopk. From the air, tion work belongs to municipal authorities or private agencies, these trees had a rusty-brown appearance owing to the com- who are in a better position to direct this cleaning-up work, pletely bare twigs. Examination of trees known to have been undertaken in conjunction with Government services for "red-tops" in mid-summer 1951 revealed similar conditions. scouting and laboratory diagnosis of diseased trees. Examination in September, 1952, of trees known to have Control of this malady by insecticide sprays was tested been attacked by D. piceaperda during the preceding spring in the United States and in Canada with promising results. and summer revealed mature or developing broods of this In order to demonstrate the practical value of this method insect under the bark, although the foliage was still on the of protection, its application and its effects in selected sites trees and was normal in appearance. It is therefore possible should be closely followed. A favourable occasion to collect that the red-topped white spruce trees which were plentiful in useful data on this treatment arose when the Oblate Fathers 1951 were first attacked in 1950, and that in 1953 there will expressed their desire to protect some 350 elms growing on be a recurrence of red-topped trees indicating the extent of their estate at Cap-de-la-Madeleine. In this particular loca- the 1952 attack. tion about 15 trees have already succumbed from this Two study plots, one of 7 . 5 acres on Black Sturgeon Lake dise-se, and were promptly cut down, most of them in 1951. and one of 0 . 4 acre on Obonga Lake were established in 1952 The insecticide was applied with a 700-pound pressure sprayer for the purpose of establishing the time which elapses before for the first time in May, 1952, before the opening of the buds. foliage of attacked trees discolours and finally drops. These The formula consisted of the following: DDT-10 lb., Xylene- plots will also be used to study the spread of bark beetle 2 gallons, Triton X-1004 pint, water to make 100 gallons. attack within the next few years. Then during the summer, each tree on the estate and all A preliminary study of the vigour of white spruce trees elms in the town of Cap-de-la-Madeleine were carefully in the area was begun in 1952, but the data collected are as examined, and every suspected tree was sampled for determina- yet insufficient to determine whether or not there is a corre- tion of disease. As expected, nine new infected cases were lation between tree vigour and mortality, and bark beetle discovered, eight of which were in the Oblate Fathers' Park, attack. Discs examined in 1952 again showed a reduction in and one in the surrounding area. These diseased trees were radial growth some 35 years ago; at present, no explanation immediately eradicated after the first treatment. The yearly can be offered for this, nor of the relationship between this examination of trees in an area of such a high disease hazard reduction and subsequent tree mortality.—J. B. Thomas. will provide useful data on the value of this preventive treat- Borer Control in Balsam, Fir, Spruce, and Jack Pine ment, which will be repeated every consecutive spring. Logs.—In 1951, logs were sprayed with an oil solution of Difficulties encountered in the execution of a sustained DDT and with water-wettable DDT in experiments on the program of sanitation and the high cost of DDT spraying prevention of borer damage in skidways in northwestern restrict the control of this disease by such methods. Hence, in Ontario; both types of sprays gave equally good results. (1) order to combat this serious malady by every means possible, (1) Blois, J. R. Borer Control in Jack Pine and Spruce Logs. the National Committee on Dutch Elm disease agreed as Can. Dept. Agric., Div. For. Biol. Bi-Mon. Prog. Rept. early as 1948 to seek immune trees and to establish a breeding 8 (1). 1952. centre directed towards the long-term task of developing In 1952, experiments were repeated using the same DDT resistant varieties. This project was first begun in 1949 at sprays to ascertain whether wettable DDT would again prove the L'Assomption Experimental Station in co-operation with to be as effective as the oil solution. the staff of that institution. Except for some exploratory Three individual standard cords of jack pine, three of work on vegetative and seed reproduction of the American spruce and three of balsam fir were selected in a cut-over elm. rooting of stem and leaf cuttings succeeded only in area. One of the piles of each species was held as a control, u one was sprayed with an oil solution of DDT (5 lb. of DDT, These results indicate that many more insects were killed 1'6 gallons of "Velsicol AR-50-G", 10 . 8 gallons of kerosene), on emerging from the egg in the logs sprayed with DDT in oil and the remaining one with 50 per cent wettable DDT (8 lb. than in the controls or the logs sprayed with wettable DDT. of powder to 10 gallons of water). In addition, three one-tier This would seem to account for the greater efficacy of the oil skidways of jack pine logs were similarly treated. The sprays spray. The DDT oil solution is able to penetrate '.the bark to were applied with a hand-operated stirrup pump prior to the some extent but the wettable DDT remains on the surface emergence of Monochamus adults. and has little or no toxic effect on the eggs or the small larvae. In mid-September, eight logs from each pile of pulpwood The disparity of results between 1951 and 1952 may be (four from the surface and four from the interior of each largely due to the much heavier rainfall during the period of pile), and four logs from each of the jack pine skidways were oviposition of Monochamus in 1952. In 1951, only 3 . 6 inches chosen at random for examination. One-foot sections at the of rain fell during the oviposition period, but in 1952, 10.9 middle and at each end of each log were examined in detail. inches of rain fell during the same period. As a consequence, All larvae occurring on the surface of the wood, except bark the wettable DDT left as a powder residue on the surface of beetles, and all entrance holes into the wood were recorded. the logs was washed off to a much greater degree in 1952 A representative portion of the larvae in the wood was than in 1951.-J. R. Blais. collected and identifications were made by Mr. L. M. Gardiner. TABLE 1 ,.. „',,,m„c., Since Monochamus were the only deep boring species encountered in the experiment, data concerning other borers Density of Monochamus larvae per square foot of log surface. ^l will not be considered here. A summary of the number of Monochamus larvae Area No. of Species Treatment examined in insects per recorded per square foot of log surface in the check and the square feet square foot treated logs is shown in Table I. It is quite apparent that DDT in oil was more effective than wettable DDT in the Balsam fir Check 40.1 6.6 1952 experiments. Wettable DDT 42.4 1.8 (72%) Monochamus egg slits were recorded on the areas DDT in oil 52.9 0.1 (98%) examined for two logs from the interior and two logs from the surface of each pile. The density of egg slits in the Spruce Check 42.7 9.5 sprayed logs averaged about 12 per square foot of log surface, Wettable DDT 42.0 2.9 (69%) whether the treatment was with DDT in oil or with wettable DDT in oil 42.2 0.9 (91%) DDT. In the unsprayed logs, the density was much greater, Jack pine Check 46.7 4.1 averaging about 30 egg slits per square foot. Thus, both sprays (cords) Wettable DDT 53.1 1.8 (57%) were equally effective in discouraging Monochamus adults DDT in oil 53.3 0.5 (89%) from ovipositing. The bark was dissected on sections of some of the treated Jack pine Check 30.0 3•7 and untreated balsam fir and jack pine logs, and records (skidways) Wettable DDT 24.5 2.1 (43%) were kept of the number of egg slits with and without eggs, DDT in oil 31.3 0.1 (98%) the number of dead eggs, the number of dead newly hatched (Per cent control, in brackets, calculated by comparison with appropriate larvae, and the number of successful larvae. The results are check logs.) shown in Table 2.

TABLE 2 Number of Empty Egg Slits and Number of Dead Eggs, Dead Larvae, and Successful Larvae in Treated and Untreated Logs Examined.

Species • Treatment Area examined Total Num- Empty Dead Dead Successful in square feet ber of slits egg slits eggs Larvae Larvae Balsam fir Check 6.2 180 109 8 1 62 (60 . 6%) (4'4%a) (0'6%) (34.4%) Wettable DDT 10.9 168 82 11 5 70 (48. 8%) (6.5%) (3.0%) ' (41.7%) DDT in oil 13.2 161 65 22 72 2 (40.4%) (13.7%) (44.7%) (1.2%) Jack pine Cheek 12.5 227 84 2 5 136 (37.0%) (0.9%) (2.2%) (59.9%) Wettable DDT 15.3 166 68 7 10 81 1 (4.2%) (6.0%) (48.8%) DDT in oil 8.6 164 (41 6 (37 . 2%) (6.1%) (50.6%) (6.1%)_.

Control of Fletcher Scale, Lecanium fletcheri Ckll., on Assessment- of the effects of the sprays on the scale insect Japanese Yew.-This insect is a widespread and serious pest of was commenced one month after application and completed Taxus in parks and ornamental plantings throughout southern before the nymphs had migrated from the foliage to the Ontario. Injury to the host plant results from a heavy foliage twigs. Mortality counts of the nymphs were made under a drop and killing of the twigs and branches. The scales pass dissecting microscope on twigs of the first and second year the winter as partly grown nymphs on the twigs and axil of the growth taken at random from near the central area of each foliage. The nymphs become active again in late April and block. The parathion spray gave 100 per cent control. The early May, and by June have settled on the twigs and formed combined nicotine sulphate and summer spray oil (2 pints their scale covering. The, small, whitish eggs are deposited, in nicotine sulphate, 1 gal. Ortho-K oil, in 100 gal. water) rated large numbers beneath the parent scale and commence to 92 . 3 per cent control and malathon 87 . 5 per cent. The other hatch about the middle of June. The young insects crawl to materials tested did not provide satisfactory control. Some the leaves, where they feed until the latter part of September, slight yellowing of the tip leaves was noted in the blocks when they move to the twigs to overwinter. sprayed with nicotine sulphate and summer oil combination. Chemical control experiments involving twelve different However, this discoloration disappeared before the end of the formulations were conducted on a heavily infested hedge of season. No foliage injury was observed in any of the other Japanese yew, Taxus cuspidata Sieb. and Zucc. The hedge blocks.-K. E. Stewart, R. J. Finnegan, C. S. Kirby. was divided into blocks, each aproximately 20 feet in length. Two blocks were used for each spray formulation except the PRAIRIE PROVINCES parathion and malathon sprays, when 200 feet of hedge were Disease Caused by Weak Parasites Associated with allotted to each. Seven blocks were interspaced among the Shade in Seedbeds.-Scots pine (Pinus sylvestris L.) seedlings treated blocks and left unsprayed to act as checks. The in nursery seedbeds at Indian Head showed a peculiar disease materials were applied with a small, portable, power sprayer, in the fall of 1952. High mortality occurred in certain patches, adjusted to develop 250-1b. pressure at the pump. The spray but rarely elsewhere. In addition to the death of approxi- gun was set to produce a finely divided but forceful spray. mately one-quarter of the 2-year-old seedlings in these patches, Both the sides and top of the hedge were treated. The sprays, a still greater number developed abnormally, showing various with the exception of parathion and malathon, were applied symptoms. Many needles had been killed, often at one side during the first week in July. At this time 90 per cent of the of a seedling more than the other. Frequently the tip was eggs had hatched and 60 per cent of the young nymphs had dead and the stem swollen. Sometimes buds, branches, or moved out from under the parent scale. The parathion (15 abnormal needles were developing. Also, many of the 3-year- per cent wettable powder at 21- lb. per 100 gal. water) and old seedlings were killed. malathon (25 per cent wettable powder at 3 lb. per 100 gal. The disease occurred only where double lath at thee* water) were applied on July 22 after all the eggs had hatched junction of two screens caused heavy shade. Because the and the nymphs approaching the second instar. protection otherwise should be of advantage for the seedlings, the disease evidently resulted from the lack of sufficient light. living tree of lodgepole pine, 55 years old and 9 inches in However, the shade alone could hardly kill the seedlings, but diameter. The tree received close inspection when several probably lowered their resistance to parasites. sporophores of a Basidiomycete (Poria sp.?) were found fruit- In experiments at Helsinki and Yale Universities, it was ing on the outer bark. Fifty per cent of the cambium at found that Scots pine seedlings were killed by several weak breast height was dead from undetermined causes. The fungus parasites under shade, but not in full light'. Because the is unknown and is receiving further consideration for identifica- symptoms in these experiments resembled those described tion as to species. The tree was felled and sectioned and above, it is supposed that the disease at Indian Head is also several isolations were made from the abnormal wood variously caused by the combined effect of shade and weak parasites. discoloured in blue ,and pink. In addition to the Basidiomycete Isolations from diseased stems yielded several fungi. At least a f ew interesting Hyphomycetes were obtained in culture. some of these are known as weak parasites, namely Fusarium These fungi, confirmed as to identity by Mr. S. J. Hughes, monilif orme Sheld. emend. Snyder & Hansen, F. acuminatum are listed in the following tabulation: Ell. & Ev., F. oxysporum Schlecht. emend. Snyder & Hansen, Dematium pullulans de Bary, Alternaria sp., and (in one case) Number Helminthosporium sativum Pamm., King & Bakke. The study of Decay or Stain Associated Fungus is being continued.-0. Vaartaja. Isolate Diseases of Insects.—The polyhedral virus disease which 1 White, flaky decay Poria sp.- wiped out the balsam-fir sawfly, Neodiprion abietis (Harr.), in 2 Pink stain Zythia resinae (Ehrenb.) Karst. northern Saskatchewan during 1950 and 1951 has not been 3 Pink stain Cephalosporium sp. 4 Pink stain Leptographium lundbergii found in Manitoba and Alberta, although the sawfly is still Lagerb. and Melin present there. Overwintering larvae of Archips conflictana 5 Blue stain Cephalosporium sp. (Wlkr.) from an outbreak area near Grenfell, Sask., were 6 Blue stain Cytospora sp. infected with the fungus Beauveria globulifera. The small larvae had been numerous under the bark of aspen poplar, A Leaf-Spot Disease of Aspen.--,A leaf-spot disease of but all that remained of about 90 per cent of them was the trembling aspen, (Populus tremuloides Michx.), developed in head capsule and a mass of compact white mycelium. A epidemic proportions in the Canmore-Banff area of Alberta polyhedral virus disease was present in Nymphalis antiopa (L.) in 1952. The disease was noted first in late August when the feeding on willow at Swan Lake, Man., and Bladworth, Sask.; crowns of affected trees showed a bronzed discoloration. a polyhedral virus was also found in Vanessa cardui (L.), Premature defoliation occurred. The associated fungus, which was common on thistle in 1952. In 1949, an undeter- identified with the genus Marssonina, was confirmed by Dr. mined disease caused the decline of an outbreak of Hyalophora R. F. Cain to be M. tremuloidis Kleb. This appears to be cecropia (L.). This year Microsporidia were found in dead the same fungus which other investigators have included prepupae from Pashley, Alta., but it is not known if they under M. populi (Lib.) Magn. The high rainfall in the region were the primary cause of death.—Margaret E. P. Cumming. during the past season has provided conditions ideal for ROCKY MOUNTAIN REGION epidemic development.—Vidar J. Nordin. Dwarf Mistletoe on Spruce in Alberta. —A species of RECENT PUBLICATIONS Arceuthobium has been found attacking white spruce (Picea glauca (Moench) Voss) on the Kananaskis Forest Experi- Foster, R. E. and A. T. Foster. mental Station, Seebe, Alberta. This mistletoe plant appears Estimating decay in western hemlock. Suggested aids to different from the mistletoe (Arceuthobium pusillum Peck) the inventory in the Queen Charlotte Islands. B.C. that attacks white spruce in the East. Arceuthobium pusillum Lumberman, 36 (11) : November 1952. rarely attains a height of more than 4 inch, while the plants Ghent, A. W. collected at Kananaskis were up to 11 inches in length. This A technique for determining the year of the outside ring attack was noted in mid-September when there were no flowers of dead trees. For. Chron. 28, 4:85-93, 1952. present, hence positive identification must be delayed until an Lindquist, 0. H. examination of the flowers can be made. The affected spruce A device for capturing adult insects in rearing containers were the remnants of a spruce-pine (Pinus contorta Dougl. var. and cages. Can. Ent. 84, 12:380-381, 1952. latifolia Engelm.) mixture whose pine component had been Balch, R. E. cut out as a control measure after attack by the lodgepole Current practices and future trends in forest insect pine mistletoe (Arceuthobium americanum Nutt.). There is control. For. Chron. 29:6-13, 1953. a possibility that A. americanum may have in this case become Holoway, C. F. and G. H. Bergold. parasitic on white spruce.—R. J. Bourchier. Iron content of an insect virus. Science 117, No. 3036: Miscellaneous Fungi in Lodgepole Pine in Alberta.—A 251-252, 1953. number of interesting fungi have been found occurring in a Turner, K. B. The relation of mortality of balsam fir caused by the 1Vaartaja, 0lli. Forest humus quality and light conditions as factors spruce budworm to forest composition in the Algoma influencing damping-off. Phytopathology 42:501-506. 1052. forest of Ontario. Publ. 875, Canada Dept. Agr. 1952. EDMOND CLOUTIER, C.M.G., O.A., D.S.P., Queen's Printer and Controller of Stationery, Ottawa, 1953.

• *i CANADA DEPARTMENT OF AGRICULTURE SCIENCE SERVICE-DIVISION OF FOREST BIOLOGY

Vol. 9 May-June REPORT BI-MONTHLY PROGRESS REPORT 1953 Number 3 Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

CURRENT ACTIVITIES MARITIME PROVINCES collars of the trees during the years 1949 to 1951. Reports from the Forest Insect Survey indicate that similar 'conditions Biennial Cycle of Injury by Pine Leaf Chermes.- have prevailed throughout New Brunswick. Studies of the pine leaf chermes, Pineus pinifoliae (Fitch), in The following five arbitrary classes were used on the central New Brunswick since 1946 have shown a biennial cycle plots as a measure of scale abundance: None, Trace, Light, of abundance and injury to white pine. This is related to its Medium, and Heavy. The abundance of the predacious beetle, complex two-year life cycle. A winged form (gallicola) goes Chilocorus stigma, was determined by counts made on the from red spruce to white pine one year and another winged basal 6 feet of each tree. The relationship of Nectria infection form, descended from it (sexupara) returns to the spruce the to tree mortality was also noted. The five classes of scale following year. There are intermediate wingless forms. In abundance were given numerical ratings in approximate pro- any one year two generations are present, each represented portion to the populations represented, as follows: None, by different forms. All forms are subject to various factors 0; Trace, 1; Light, 8; Medium, 27; and Heavy, 64. The of natural control. Any factor operating selectively on one average ratings by years of all surviving trees on each plot form would establish a difference between population levels are shown in the table. The data have been arranged in of the species in alternate years. The life cycle is such that different ways in order to portray the scale abundance trends this is likely to be maintained until the rhythm is disturbed common to all trees, and the relationship of low winter by unusually severe selective mortality operating on the temperatures, and to determine the probable role of the abundant generation. predator. The following conclusions are drawn: The greatest mortality observed has been to the dormant 1. The scale outbreak in the Fredericton area has lasted first stage offspring of the gallicola on the new shoots of the for a period of about 14 years. During this !time the pine. Studies near Fredericton, N.B., in 1951 and 1952 showed percentage of beech killed amounts to about 20 per cent that the mortality during the summer (June to October) by stems and about 40 per cent by volume. Some trees averaged about 68 per cent, based on 15,287 larvae, and during appear to be dying as a delayed result of severe attack the winter (October to April) this increased to about 90 per followed by Nectria infection. Many of the surviving trees cent, based on 15,795 larvae. indicating an equal mortality of are considerably cankered. A considerable increase in about 68 per cent in both seasons. The shoots were moderately scale abundance took place in 1952 and a new outbreak infested. Mortality is often complete on heavily infested may be developing. shoots owing to the death of the shoot or competition for food. 2. A general build-up in the scale infestation on plot 1 This type of mortality might tend to disturb the cycle of commenced about 1938 and reached a peak in 1942. A abundance but has not yet been observed to do so.-G. R. reduction in scale abundance occurred in 1943 and 1944 Underwood. following the low winter temperatures during 1942 and Additional Observations on the Beech Scale.-The re- 1943. During 1945 the scale again increased in abundance. sults of studies on the beech scale outbreak and associated This was followed by a further decline during 1946 and Nectria infection in the Fredericton area of New Brunswick 1947 at a time when the predator population was reaching its peak on this plot. It was not until 1948 that the up to 1946 were recorded in a previous number of this report elimination of practically all infestations above the root (Vol. 3, No. 4, 1947). About 1948 there was a sharp decrease collars took place. On plot 3 the scale population com- in the abundance of scale near Fredericton, N.B., and the menced building up in 1942, reaching a peak of abundance residual scale population was confined mostly to the root in 1946 and 1947.

Abundance of Scale (S) and Predator (P), Tree Mortality and Winter Temperatu es 1939-52

Scale or Abundance ratings predator 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952

P of 1 S 3 9 29 38 22 15 21 14 7 3 2 3 2 6 P 0 0.1 0 . 2 0 . 8 1 . 2 0 . 3 0 . 9 4 . 2 1 . 4 0 . 6 0 . 2 0 0 0 Plot 3 S 0 0 0 1 3 3 7 9 9 3 3 3 2 3 P 0 0 0 0 0 0.1 0 . 2 0 . 8 1 . 6 0 . 6 0 . 2 0 . 1 0 . 1 0 Southeast half Plot 1 S 5 11 33 42 20 10 12 8 6 3 2 3 2 6 P 0 0.1 0 . 3 1 1.3 0 . 2 0 . 3 0 . 7 0 . 9 0 . 5 0 . 2 0 0 0 Northwest half Plot 1 S 2 8 24 35 25 20 30 21 9 3 3 4 2 6 P 0 0.1 0 . 2 0 . 7 1 . 1 0 . 3 1 . 6 8 2 0.6 0 . 2 0 0 0 57 Trees becoming heavily infested S 5 14 41 , 56 30 21 32 19 9 3 2 3 2 6 P 0 0.2 0 . 4 1 . 2 1 . 9 0 . 4 1 . 3 6 1.6 0 . 6 0 . 2 0 0 0 41 Trees becoming moderately infested S 2 4 14 18 15 10 14- 12 9 3 2 4 2 6 P 0 0.1 0 . 1 0 . 2 0 . 4 0 . 1 0 . 6 2 . 4 2 0.8 0 . 1 0 . 1 0 . 1 0 33 Trees becoming lightly infested S 0 1 3 4 4 3 4 6 6 3 2 3 2 4 P 0 0 0 0 0 0.1 0 0.3 0 . 7 0 . 4 0 . 2 0 0 0

Air temperatures in ° F. for 3 winter Lowest -19 -18 -21 -29 -27 -21 -22 -21 -25 -31 -21 -21 -20 -25 months, Dec.-Feb. Days-25° or lower 0 0 0 1 1 0 0 0 1 4 0 0 0 1

72744 2

3. The predator population was also later in reaching its for hybridization is calculated to be about 12 per cent. Again peak. This, and the data for 1943-1944, 1946-47, for in relation to population density, a sample of 200 mating plot 1, suggest that perhaps predator activity played an pairs should comprise about 138 spruce budworm pairs, 12 of important role in reducing the scale during those years. each of the two reciprocal hybrid pairs, and 38 jack-pine pairs. A similar conclusion may be reached on examining the Actually, the approximately 230 budworm matings observed data for the southeast and northwest halves of plot 1; during the period of overlap provided none that were inter- also that for the heavily, moderately, and lightly infested specifics. Sexual isolation was therefore absolute. trees. It may be mentioned here that during these studies In agreement with extensive records compiled from the predator generally did not become very abundant on insectary experiments, the mean daily mating time for the trees until they became moderately or heavily infested. spruce budworm preceded that of the jack-pine budworm by 4. An examination of air temperatures for a 20-year period approximately two hours. Although contributing to sexual from 1933-1952 showed that 1948 was the coldest of any isolation, this difference played only a minor part, however, winter since 1934, at which time populations of the balsam for the overall mating period extended from the early after- woolly aphid, Adelges piceae (Ratz.), occurring above the noon until well after midnight. snow-line were reported to have been eliminated. The These observations thus show the efficacy of reproductive lowest temperature in 1948 (-31° F.) came within one isolation and nullify the possibility that hybrids, with en- degree of the lowest recorded in 1934 (-32° F.). It is hanced vigour and unknown food preferences, constitute a suggested that the widespread reduction in scale in 1948 threat to the welfare of the Canadian forests.—S. G. Smith. was due to conditions associated with low winter tempera- References tures and that decreases occurring on some plots or trees Freeman, T. N. 1953. Can. Ent., 85: 121-127. in 1943-44, 1946-47 was due in part to the increased Smith, S. G. 1953. Reproductive isolation and the integrity activity of C. stigma.—G. W. Barter. of two sympatric species of Choristoneura (Lepidoptera: ONTARIO Tortricidae). Can. Ent., 85: 141-151. A Breakdown among the Components that Provide Wellington, W. G. 1948. The light reactions of the spruce Reproductive Isolation between the Spruce and Jack-pine budworm, Choristoneura fumiferana (Clemens) Lepidop- Budworms.—The spruce and jack-pine budworms are con- tera: Portricidae). Can. Ent., 80: 56-82. sidered to be distinct but closely related species in the genus PRAIRIE PROVINCES Choristoneura (Freeman, 1953). Because they will hybridize Substitute Shoot Production by Tamarack. —The larch with comparative ease in captivity yet show no evidence that sawfly acts in two ways to bring about a reduction in, and cross-mating occurs in nature, the factors which ensure their a suppression of, terminal shoot development of the host trees integrity, the so-called isolation barriers, have been studied in years following initial attack. Injury is caused directly over a number of years and have been summarized recently by the ovipositing adult and indirectly due to after effects of (Smith, 1953). defoliation by the feeding larvae. It has been reported that Large populations of the two species are isolated geo- such injury may influence sawfly population trends by reducing graphically owing to the different distributions of their host the number of available oviposition sites. trees. Where populations occur together, crossing is seem- In the Whiteshell Forest Reserve, Manitoba, and in the ingly prohibited by a number of components that, taken as a southeastern corner of the Province, severe defoliation has whole, constitute reproductive isolation. These have been been reported for five and six successive years, respectively. found to include ecological, temporal, and sexual isolation. Last summer, trees throughout both these areas were observed The most obviously effective of these is the temporal factor, to have produced large numbers of substitute shoots. Many for, so far as was known up until March, 1952, the mating of the trees bore few or no apical shoots but had produced season of the spruce budworm is finished before adults of the substitute shoots in great profusion. Most of these shoots jack-pine budworm appear. This seasonal difference results arise from lateral buds or "spurs" which under normal condi- from the later spring, emergence of overwintering jack-pine tions would produce fascicles of needles. In 'many cases budworm larvae combined with a slower rate of subsequent epicormic shoots were observed growing from the main stem development. and larger lateral branches. These abnormalities of growth In May, 1952, Forest Biology Ranger W. J. Miller and I were observed on trees varying in height from 5 to over found that the two species had resumed activity at much the 30 feet. same time, doubtless owing to the unseasonably high tempera- The stimulus for the production of these substitute shoots tures that prevailed earlier throughout western Ontario. The appears to originate from the injury resulting in the destruc- anticipated breakdown of the temporal barrier promised a much tion of the apical buds and killing of the terminal portions of sought-for opportunity to assess the relative efficacy of the the branches. Mechanical injury caused by pruning or other ecological, temporal, and sexual components of reproductive means induces a similar growth response. isolation. The substitute shoots provide suitable oviposition sites Mass collections of budworms made at about pupation for the adult sawfly. It would seem therefore that reduction time near Vermilion Bay in the Kenora District revealed that in foliage volume, of those trees whose vigour has been only spruce budworm was present on balsam fir, but that reduced by repeated defoliation, would exert a greater influ- about 3 . 2 per cent of the moths emerging from the collection ence on larch sawfly population than a reduction in apical taken off jack-pine were of this species, the remainder being shoot production—R. J. Heron. jack-pine budworms. The delayed eclosion of the 3 . 2 per cent Some New Predators of the Larch Sawfly. —In the course relative to those emerging from the balsam fir collection was of investigations into the ecology of the larch sawfly several sufficient evidence that they had actually matured on jack- previously unrecorded predators were observed. Four species pine. Adjusting the numbers available in accordance with of mirid bugs, Phytocoris neglectus Kgt., Deraeocoris laricicola the relative population densities (about three spruce bud- Kgt., Plaziognathus repeticus, Kgt., and Tetraphleps sp., were worms to one jack-pine) sets the efficacy of larval ecological found feeding on larch sawfly eggs and newly hatched larvae; isolation at between 97 and 98 per cent. Adult flight results an orb spider, Neoscona arabesca Walckenaer, fed upon young in a considerable lowering of this value, for although those larvae that became trapped in its web; and a small pink mite, females found on the `wrong' trees were almost invariably Balaustium sp.. preyed upon first- and second-instar larvae. spent, the occasional misplaced male was noted before females The effectiveness of these predators is difficult to assess, but of the saine species entered the population. The isolation from the numbers of individuals present on tamarack sup- imposed on the species by the different feeding preferences porting a larch sawfly population, it appears that the mirids appears, then, to be sustained at maturity by the females and the mites may be fairly important in natural control. alone; this is attributable to their inability to fly when fully The spider is unlikely to be of importance as it habitually gravid (Wellington, 1948). The freedom of flight shown by preys on flying insects.—W. J. Turnock. males, however, reduces its efficacy as an isolation barrier in Population Studies on Bessa harveyi.—Preliminary studies the direction of one-half. en Bessa harveyi Tns.. a parasite of the larch sawfly, suggest Adults were present on the wing over the period June 29 that this parasite is poorly synchronized with its host. Adults to July 25 inclusive. Between July 6 and 23 about 80 per cent of the parasite emerged in the fall from approximately of the male and 86 per cent of the female population of spruce 10 per cent of a group of 750 parasitized larvae collected budworms occurred with some 85 per cent of the male and during the summer. However, the majority of these adults 77 per cent of the female jack-pine budworms. Weighted on emerged after the last host larvae had fallen from the trees. the basis of the different relative population densities, these Such adults are therefore ineffective against the larch sawfly proportions show that temporal isolation broke down to the unless they are able to overwinter successfully. Adult para- extent of 86 per cent. sites emerged from 63 of 71 puparia that were formed in the Tests of the nuptial status of females established the pro- fall. Seven of these puparia were dead when found and portions of the overlapping females (and by inference of the only one remained to overwinter in an apparently healthy males) that were unmated at any particular time of the overall condition. Thus, most B. harveyi overwinter as larvae within flight season. Assuming mating to be at random, the potential the bodies of their hosts. 3

The seasonal period of B. harveyi oviposition determined It is apparent from the accompanying table and diagram the time of adult emergence in the fall, i.e., the first eggs laid that in this instance at least the stand condition is related produced the first fall adults, etc. Those eggs which were to the soil conditions. It is concluded that unfavourable laid later in the season required increasingly longer periods soil conditions in Plot 2 have affected the vigour of the trees of development probably due to the decreasingly favourable and this may have rendered them susceptible to attacks by climatic conditions. fungi and insects. Possibly also the environment is favourable The percentage of the parasitized host larvae in each of for the development of fungi and insects. six collections made during the summer from which B. harveyi Further investigations are required to be sure that at larvae emerged in the fall and formed puparia was as follows: least some of the factors mentioned above are constantly associated with the stand openings. Other factors also should Percentage parasites be investigated. The study is being continued in 1953 in Date of collection producing puparia co-operation with a forest entomologist of the Winnipeg July 8 9.4 Laboratory-H. van Groenewoud. July 14 11.7 Tree Seed Insects.-On May 4, 1953, cones which were July 21 22.1 produced in 1952 were collected from the ground below white July 28 10 •6 spruce trees on the Forest 'Nursery Station, Indian Head, August 4 2.9 Sask. A sample of 74 cones was examined to ascertain the extent of infestation by the cone seedworm Laspeyresia August 11 0.6 youngana (Kft.), and to obtain information on the stage of -J. Muldrew development of the insect and mortality caused by parasites. Openings in White Spruce Stands at Candle Lake, On May 5, a similar sample (75 cones) was collected from a Saskatchewan.-This report is supplementary to a report white spruce tree on which the cones had remained during under the saine title by R. D. Whitney and H. van Groenewoud the winter. The following information was obtained: in the Bi-Monthly Progress Report for November-December, 1952. The object of this project is to explain the mortality of Cones No. and stage of groups of white spruce in otherwise uniform stands. Pre- Infested insects present Mortality in larval stage liminary investigations have indicated that a relationship Insects exists between mortality, root-rot diseases, a root-attacking Parasitized insect, and soil conditions. Cause Unknown Sample No. % Larvae Pupae Unknown % of total Following is a comparison of soil conditions in a stand No. Insects opening caused by dying trees (Plot 2) and a control plot (Plot 4). The stand is approximately 85 years old. The plots were on the same ground-level and approximately Ground 60 81 . 1 61 19 17 35 43.8 80 feet apart. Tree 58 77 . 3 56 24 8 32 40.0

o Ao In both samples the number of insects present is greater Al than the number of cones infested. This is explained by the fact that some cones were infested by more than one larva. In A2 the "ground" sample the number per cone varied from one to three and in the "tree" sample from one to four.-A. F. Hedlin and C. Y. Hovey A2 Summer Program, Laboratory of Forest Biology, B Winnipeg.-Infestation trends of two important forest insects, the spruce budworm and the forest tent caterpillar, will be closely watched in 1953. In 1952, the presence of a spruce G - 1 FOOT budworm infestation at Namew Lake on the Manitoba- Saskatchewan border was confirmed. The infestation covered B about 5,000 acres in a predominantly white and black spruce area. Plans have been made to determine the extent and severity of the infestation in 1953 and assess the danger of tree mortality occurring in the stands attacked. Tent cater- pillar outbreaks are expected in eastern and southeastern Manitoba and in northern Saskatchewan. Outbreak areas will be mapped and mass rearings of larvae, pupae, and eggs undertaken to determine the degree of control being exerted C by parasites and disease. An egg survey is again planned for the fall of the year to aid in predicting probable outbreak - 2 FEET areas for 1954. The following is a summary of research projects in progress * FIELD CAPACITY PERCENTAGE during the current season. At Prince Albert, Sask., work is ** AIR CAPACITY PERCENTAGE continuing on studies to determine the effect of site differences *** SOIL VOLUME PERCENTAGE on larch sawfly infestations and on the injury sustained by the tamarack trees. Two typical site types are being investi- Diagram showing the two profiles with some of gated, the wet, pure tamarack type, and the drier spruce- the physical features tamarack mixture. In the Whiteshell Forest Reserve, Man., four projects on the larch sawfly are underway. One has as its objective the development of reliable sampling techniques TABLE I to measure changes in sawfly populations. Such techniques are essential for determining the effect of various natural Plot 2 Plot 4 control factors on sawfly abundance. A second project is concerned with the effect of starvation and competition for 1. Shallow Beta-gley profile 1. Well developed ABC- food on infestation trends. The third deals with the role of 2. High field capacity (36%) profile small mammals as predators of the larch sawfly; small mam- 3. Low air capacity (7%) 2. Normal field capacity mals are important larch sawfly predators but their part in 4. Carbonates absent in top- (22%) the biological control picture has received scant attention in soil 3. Moderately low air capa- tire past. The fourth project is a study of the factors 5. pH humus 4.4 city (12.5%) influencing the effectiveness of Bessa harveyi, an important 6. Clay content A2-layer 7% 4. Carbonates present in top- parasite of the larch sawfly. 7. A2-layer very low in soil At Candle Lake, Sask., in co-operation with the Labor- water soluble salts 5.. pH humus 7 atory of Forest Pathology, Saskatoon, the causes responsible 8. Low temperature, 4°C. at 6. Clay content A2-layer 11% for openings in spruce stands are being investigated. The 2 feet, July 28, 1952 7. A2-layer moderate amount main efforts of personnel from the Winnipeg Laboratory will of water soluble salts be directed towards determining the importance of Hypomolyx 8. Higher temperature, 8°C. piceus, a root weevil, as a factor contributing to these at 2 feet. July 28, 1952 openings. 4

Other laboratory projects are studies on the taxonomy associated with two pitch moths tentatively identified as of sawflies and the life history of the large aspen tortrix, a Dioryctria zimmermani Grote and Vespamima novaroensis Hy. defoliator of poplar.—R. R. Lejeune Edw. The habits of the Laspeyresia sp. appear similar to those of the pitch moths in that a short, irregular gallery ROCKY MOUNTAIN REGION is mined in the inner bark and pupation occurs in the pitch Red Stain and Decay of Lodgepole Pine in Alberta.— nodule.—J. Walters Investigations have been made of stain and decay in 133 living trees of lodgepole pine distributed in five 1/10-acre Nursery Insect Investigations.—The practice of preven- plots located in the vicinities of Strachan (2 plots), Nordegg tive application of chlordane to land undergoing fallow phase (2 plots), and Water Valley (1 plot). An unidentified fungus, of rotation received support this spring. Chlordane as dust arbitrarily called "Unknown L" according to the original was applied to fallow in the Duncan Forest Nursery, Vancouver designation by Dr. M. K. Nobles, was the basidiomycete Island, in 1950, at the rate of 6 pounds actual chlordane per isolated most frequently from red-stained heartwood. The acre. The area was later seeded to a cover crop of oats and basidiomycetes identified in association with "red stain" are plowed in at heading. A check area, three beds wide, tra- listed in the following table: versed the entire length of this field. Although the strawberry root weevil (Brachyrhinus ovatus (L.)) began in this area as a light infestation, no losses Number Percentage due Fungus of of to root-weevil attack were evident within the treated portion Isolations Isolations when the seedlings were lifted this spring. Of the thirty beds in the untreated check area, three beds (about 30,000 seedlings) Unknown L 129 85 were unfit for planting because of root injury by weevils. Fomes pini (Thore) Lloyd 10 6 This observation is encouraging since 8 pounds of actual Stereum sanguinolentum Alb. Schw. ex Fr. 5 3 chlordane per acre have been applied by spray, in succeeding Polyporus anceps Peck 4 3 years, to other sections of the nursery. Poria taxicola (Pers.) Bres. 1 1 Fomes pini and Unknown L 1 1 At the Green Timbers Forest Nursery, in the Fraser Unidentified 2 1 Valley, a recurrence of strawberry root weevil has taken place after a period of over ten years during which no Totals 152 100 attacks occurred. As at Duncan, no prior indication of In the three areas and age class (84 years) of lodgepole infestation was found, detection being made when stock was pine examined, it is particularly interesting that Fomes pini lifted for planting out this spring. About 200,000 seedlings was associated with only a small percentage of the isolations were destroyed. This was a very serious loss because planting • from "red stain". Previously, F. pini has been considered to and labour conditions were ideal this year and large areas are be the major fungus responsible for this decay. Eighty-five suitable for reforestation. Plans are now underway to put this additional isolations from "red stain" yielded a variety of nursery on a permanent preventive program based upon experi- hyphomycetes, including genera such as Cytospora and Zythia. ence with chlordane in the Duncan Nursery.—D. N. Smith The significance of these fungi is being investigated. Three Insects Afectingf Wood in Service.—The problem of infections of brown cubical decay and eight infections of insects affecting wooden structures is becoming increasingly white pitted decay were associated respectively with Conio- acute on the West Coast. The principal insects concerned phora puteana (Schum. ex Fr.) Karst. and Polyporus abietinus are termites, carpenter ants, and powder-post beetles Dicks. ex Fr.—Vidar J. Nordin, Willma Sutton, and J. W. (bostrichids). The last-named are apparently the most Heming. serious pests. As the result of years of continuous infestation BRITISH COLUMBIA by the anobiid beetle Hadrobregmus destructor Fisher, an Laspeyresia sp. as a Bark Moth on Western White Pine, old house recently collapsed in Victoria, B.C. It is certain —Although some of the species of the genus Laspeyresia are that many houses in Victoria are heavily infested in the same cambium miners on various coniferous trees it appears that manner and several are definitely known to this laboratory. none have been reported from Pinus monticola Dougl. One Two buildings are under observation following spray adult and two pupal cases, identified by T. N. Freeman, treatments. One house received a commercial preparation Systematic Entomology Unit, Ottawa, as Laspeyresia sp. of copper naphthenate, with an additional spray of pentach- probably piperana Kft., were recovered in April, 1953 from the lorophenol to some parts of the infested timber. The second bark of white-pine logs collected in November, 1952, at house received the latter compound in two formulations. The Magna Bay, Shuswap Lake, B.C. In January, 1953, sections results have not yet been evaluated.—D. N. Smith of the logs were placed in an incubator at the Vernon Labor- atory of Forest Biology. Correction.—The names of the authors, V. J. Nordin and Laspeyresia piperana Kft. is well known as a cone moth Willma Sutton, were inadvertently omitted from the article but had not previously been reported as a 'cambium miner. entitled "Miscellaneous Fungi in Lodgepole Pine in Alberta" The species of Laspeyresia collected from white-pine bark was on page 4 of the March-April number.—Editor. EDMOND CLOUTIER, C.M.G., O.A., D.S.P., Queen's Printer and Controller of Stationery, Ottawa, 1953.

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• CANADA DEPARTMENT OF AGRICULTURE SCIENCE SERVICE-DIVISION OF FOREST BIOLOGY

VOL. 9 REPORT July-Aug. BI-MONTHLY PROGRESS REPORT 1953 NUMBER 4

Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

CURRENT ACTIVITIES

MARITIME PROVINCES on the 'Green River Watershed, NB., in 1948, and in 1950 Susceptibility of Species of Fir to Balsam Woolly it became an important factor in the natural control complex Aphid Adelges piceae (Rata.). -In Canada this insect kills of a light budworm infestation. balsam fir, Abies balsamea, in two or three years by heavy Although little is known of the life history of the attack on the stem or causes stunting and slow death by lighter parasite in this area there are two general characteristics attacks on the twigs. It produces a swollen condition of the of the species that limit its effectiveness as a natural control twigs known as "gout disease", and also an abnormal agent of the budworm. One is the necessity for alternate growth of the tracheids resulting in a dark, brittle type of hosts prior to the time of budworm oviposition. The other wood known as "redwood". is that a number of eggs are deposited in each host egg; Reports from Europe have suggested that Adelges piceae an average of 3 . 7 adults per host egg emerging from bud- caused little damage and that injury to fir was attributable worm egg masses collected in 1950. The latter characteristic to A. nusslini, a closely related species that has not been limits the total number of eggs that could be parasitized found in Eastern Canada. This difference might be the and may be the result of poor searching ability coupled with result of a difference in the insects or in the tree species a high rate of oviposition. involved. Recent observations by the writer in Europe The accompanying table shows the number and per- seem to show conclusively that it is !a matter of difference centage of eggs parasitized by T. minutum on certain repre- in the susceptibility of balsam fir and the European silver sentative plots. On Plots 5, 2, 4, and Q the percentage of fir, Abies pectinata, to be salivary injections of Adelges eggs parasitized declined in 1951. Presumably this decline piceae. was related to a decrease in the availability of one or In Switzerland and Germany a number of heavy in- more alternate hosts in that year. On Plot 4 the percentage festations of silver fir by Adelges piceae were seen which of eggs parasitized decreased in 1950. although the actual would have been sufficient to kill balsam fir rapidly, but the number of eggs increased owing to a relatively high host silver 'fir showed no signs of injury, "gout", or "redwood". density. This latter fact is a further indication that the This was confirmed by Dr. J. Franz and Dr. V. Delucchi effectiveness of the parasite in this study was limited by the with whose kind assistance the examinations were made. alternate host or by other factors, and was not a function In Holland, through the courtesy of Dr. 'Th. C. Oudemans, of budworm egg density when this density rose above a 15-year old plantings of many species of Abies were seen at certain level. This level is difficult to define but in 1950 it the Schovenhorst Arboretum near Putten. Of these, only was much lower than 458 eggs per 10 square feet of foliage. Abies balsamea and A. fraseri (a very closely related species The results for Plot K1 were included to show the low per- found at high elevations in the southern Appalachians) showed centage of eggs parasitized in 1951 and 1952 in a heavy any injury. They were suffering severely from "gout". budworm infestation. much stunted, and only a few feet high. All other species Egg-population sampling was carried out on 10 co- had grown rapidly, although slight "gout" was found on dominant trees on each plot with each 'crown divided into Abies nobilis. No heavy infestations were seen. quarters and denoted as levels A, B, C, and D. In 1950 the This confirms the previous conclusion that A. piceae total number of eggs and percentage of eggs parasitized were was introduced to Canada from Europe and its greater recorded separately for each crown level. Percentages were destructiveness here is due to the high sensitivity of our converted to angles and the data analysed for intra-tree native fir to the salivary injections of the insect as well as variability in the percentage of parasitized eggs. On Plots 2 the inadequacy of natural control. and 4 no significant difference was found, although on Plot A very large number of species of conifers from different 4 there was a significantly higher host egg population within parts of the world have been planted during the past level B. On Plot 5, after combining the data to levels AB hundred years at Schovenhorst by Dr. Oudemens' family- and CD, the percentage of eggs parasitized was significantly a remarkable example of private effort in forestry research higher within the top half of the crown. Plot 5 is a dense from which much information of this kind can be obtained. stand of young balsam fir where the lower crown levels are -R. E. Balch. shaded to a certain extent. The presence of the parasite in Parasitism of Spruce Budworm Eggs by Trichogramma the upper crown might be attributed to the relative amount minutum Riley.-T. minutum has been recorded previously of light since other workers have shown that the amount as a spruce budworm egg parasite, but its control value has of light is a factor influencing the activity of T. minutum.- generally been rather low. It was found for the first time C. A. Miller. Egg Population, and Number and Percentage of Eggs Parasitized per 10 Square Feet of Foliage (1), 1917 to 1952, Green River, N.B.

1948 1949 1950 1951 1952 Plot Par. Par. Par. Par. Par. Eggs Eggs Eggs Eggs Eggs No. % No. % No. % No. % No. %

5(2) 13 . 1 4.7 35.5 21.2 8.9 41.9 35.2 17.0 48.3 7.6 1.0 11.2 37.1 3.3 8.8

2 (3) 39 . 3 13.1 33.3 38.1 9.9 26.1 64.7 31.1 48.0 21.6 4.3 20.1 71.9 0.0 0.0 4(3) 39 . 3 0.0 0.0 86 . 5 31.0 35.8 458 . 0 104. 9 22.9 194.0 13.2 6.8 173 . 7 4.0 2.3 Q(4) 69 . 3 31.7 45 . 7 21.2 5.4 25.6 62.7 8.2 13.1 K1(3) 2778 . 0 25 . 0 0.9 1125 . 5 5.6 0.5

(1)An average of 600 square feet of foliage on a mature balsam fir. (2) Dense stand of 35-year old balsam fir. (3)Mature balsam fir. (4)Mixed wood stand. 75402-1 2 Decay of Balsam Fir.—During the period 1949-1952, unsuccessful in accounting for the differences observed.— approximately 3,450 living balsam fir from six areas located A. G. Davidson. in New Brunswick, Nova Scotia, and Newfoundland were examined to determine whether differences in the amount White Pine Blister Rust in Newfoundland.—In June, of cull due to decay existed between widely separated 1953. an extensive survey was made of the easily accessible localities in the Maritime Provinces. Since previous studies portions of Newfoundland to determine the occurrence of on decay relationships in forest trees have shown that age white pine blister rust. Samples of this fungus have been is an important influencing factor on the amount of decay, collected from Stephenville Crossing in the west to St. this variable was used to examine the relationship between John's in the east, and as far north as Lomond, Hampden, the amount of cull and locality. The distribution of trees and Springdale. The white pine observed were for the by age classes was not uniform throughout the areas most part heavily infected, particularly in the central portion investigated. and the computations were restricted to the age of the Island, where most of the white pine were either dead range of 61 to 120 years, which was fairly well represented or had dead tops with many dead branches. The population from each of the areas. Within this age range. a straight of Ribes is very high in Newfoundland.—A. G. Davidson. line relationship between age and percentage of cull seemed to fit the field data and regression lines have been used to ONTARIO express this relationship. To test the significance of the differences obtained, the Unusual Predation of the Larch Sawfly.—For the methods of covariance analysis were used. The results past four years populations of the larch sawfly, Pristiphora showed that the effect of age on the percentage of cull was erichsonii (Htg.), have been examined for disease in study essentially the same in the four mainland areas sampled plots located near the Cedar Lake Field Station, in north- (3 in northern New Brunswick and 1 in central Nova Scotia) western Ontario. and any differences between them disappeared when the During August of 1949, 1950, and 1952, a number of means were adjusted to common age. Age had a less pro- beheaded larvae were found in collection trays placed under nounced but similar effect in the samples from western marked branches, but until 1952 the agent responsible was Newfoundland and highlands of Cape Breton Island. After unknown. On 18 separate occasions in 1952, the swamp adjusting for age, however, the percentage of cull in the trees sparrow, Melospiza georgiana* (normally a seed feeder) was from western Newfoundland was significantly lower than observed through field glasses, decapitating the larch sawfly that in the trees from Cape Breton Island. The percentages larvae and discarding the bodies. The gizzards of two of of cull in trees from these two areas were also significantly these birds were examined and found to contain only sand. lower than the percentages of cull in the trees from the seeds. and fragments of larch sawfly head capsules. In five mainland regions. The following regression lines show the larch stands under observation, flocks of swamp sparrows relationship between age and percentage of cull by localities. varying in numbers from 11 to 42 birds per flock were The data from the four mainland regions have been pooled observed feeding in this manner. The white-throated sparrow because of their similarity. Zonotrichia albicollis*, the olive-backed thrush Hylocichla ustulata, and several species of warbler were also observed There are a considerable number of factors which might feeding on larch sawfly larvae, but in every case these species be expected to affect the amount of cull but the superficial ate whole larvae.—A. M. Heimpel. examination of a number of them to date has proved *Identification of the swamp sparrow and the white-throated sparrow were confirmed by Mr. L. L. Snyder, Curator of the Division of Ornithology, Royal Ontario Museum of Zoology and Palaeontology Toronto. A. MAINLAND REGIONS 40 B. CAPE BRETON ISLAND. N.S. C. WESTERN NEWFOUNDLAND PRAIRIE PROVINCES û The Spotless Fall Webworm.—Although populations oLL 30 of the spotless fall webworm, Hyphantria textor Harr., were w very low in 1952, publication of the information obtained 0 seems worth while, due to the importance of this insect in southern Europe. gi 20 Five collections were received, four larval collections o. from Manitoba and one adult collection from central Sask- atchewan. No heavy infestations were reported and only one 10 or two colonies were found at each location where larvae were collected. Feeding began in early July and pupation of the insectary reared larvae took place about mid August. Data on parasitism of the larvae have been summarized in 60 80 100 120 AGE the following table:

Larval Mortality Pupal Mortality (Man.) Living Living Living Locality Larvae Parasites Unknown Pupae Parasites Unknown Adults causes (e) causes (a) (b) ' (c) (d)

Darlingford 12 12 Oak Bluff 107 1 77 16 13 11 2 Carman 89 2 71 4 12 8 4

St. Claude 292 1 1 9 1 105 175 • 24 43 108

The hymenopterous parasites were identified by the pupae revealed that many adults were well formed, but failed Systematic Unit at Ottawa as: (a) Hyposoter pilosulus to emerge from the pupal cases.—C. E. Brown and O. H. (Prov.), (b) Apanteles hyphantriae Rly., (c) Meteorus bakeri Lindquist. C. & D., (e) Therion sassacus Vier. One dipterous parasite Egg Parasitism of Forest Tent Caterpillar.—During (d) died as a pupa and could not be identified. the fall of 1951 and 1952, forest tent caterpillar egg surveys H. pilosulus emerged as adults from the bodies of third- were conducted in the forested areas of Manitoba and Sask- and fourth-instar host larvae about one month after the atchewan in order to forecast the distribution and abundance host had died; the mean emergence date was August 24. of this insect the following years. One phase of the survey A. hyphantriae emerged as larvae from the third- and fourth- involved rearing and dissecting representative eggs bands to instar larvae of the host and immediately spun white cocoons, determine the degree •of hatchability. Results of these attached to the underside of the host larvae. The mean studies indicated that egg parasitism in 1951 was at a very emergence date of the larvae was July 28 and the mean of low level. Only 5 . 1 per cent of the egg bands were attacked adult emergence was August 8. M. bakeri emerged as larvae by parasites and of these 5 . 9 per cent of the eggs were from the host larvae. T. sassacus emerged as adults from parasitized. In 1952 there was' a marked increase in egg the pupae of the host in the incubating cabinet. . parasitism; 56 . 3 per cent of the bands were attacked by Many of the larvae and pupae died in rearing from parasites and of these 20 . 8 per cent of the eggs were unknown causes. The dead larvae and pupae were examined parasitized. The species mainly responsible for the increase for disease, but no pathogens were found. Dissection of the were identified by J. C. Martin of the Insect Parasite 3 Laboratory, Belleville, Ontario. as the chalcid fly Telenomus Since the disease affects mainly needles of spruce seedlings clisiocampae Riley. and is associated with a snow mould, it suggests the disease The number of eggs parasitized in individual bands caused by Phacidium infestans Karst. However, the fruiting appeared to be related to the amount of protective coating bodies of this fungus have not yet been found.-0. Vaartaja. or `spumaline", as defined by Hodson', present on the eggs. Radulum casearium, a Poplar Decay Fungus.-In The amount of spumaline coating varied in most areas, but a study (1) carried out on the decay of trembling aspen in egg bands could be divided roughly into three types. Table northern Ontario, Radulum casearium (Morgan) Lloyd was 1 shows the average per cent parasitism of each group. found to cause over 20 per cent of all cull losses caused by decay. In Manitoba a still higher percentage was found (2). TABLE 1 Communications with forest pathologists in North and Per cent egg parasitism in relation to spumaline covering. South America, Europe, and Northern Asia, indicate that R. casearium is confined to the north temperate region and to Canada in particular. A search of the literature revealed that Type of Egg Band Per cent very little work had been done on the physiology of this Parasitism fungus. A number of physiological experiments have been carried Completely covered with spumaline 2.3 out to establish the growth characteristics of this fungus. The rate of growth is presented in Table 1. Partly covered with spumaline TABLE 1. Area covered 2.2 Rate of average radial mycelial growth of Radulum Area not covered 60.9 casearium on malt agar at various temperatures.

Average 31.5 Temperature Daily average (Deg. C.) (mm.) Completely free of spumaline 79.4 5 slight 10 0.3 15 2.5 Hodson found that parasitized eggs in individual egg 20 3.8 bands occurred most commonly along the outer or marginal 25 7.9 rows. Eggs in this area of the band are frequently free of 30 11 2 or only partly covered with spumaline. The apparent pre- 35 10.0 ference for marginal eggs during oviposition was also observed 40 0.0 in the present studies, but the preference appeared to be lost Table 1 indicates that the optimum temperature for on bands that were free of spumaline. growth is 30°C. From this optimum the rate of growth In 1952, the rearings and dissections were conducted with tapered off gradually to 35°C., above which it fell off egg bands collected from points within the 1952 outbreaks quite sharply. Only slight growth occurred at 5°C. and from peripheral areas outside the outbreak centres. It The growth of R. casearium continues after the infected was observed that poorly coated egg bands were more frequent tree has been cut down. It is probable that extensive in the latter areas. Table 2 shows the average per cent losses may occur where pulp piles are held over for a summer, parasitism in Manitoba and Saskatchewan in the different due to the rapid growth of the fungus at high temperatures. types of study areas. The pH of the substrate has a decided effect upon the TABLE 2 rate and amount of fungal growth. To determine the optimum pH for growth, a malt agar series ranging from pH Per cent egg parasitism in different types of areas. 2 . 5 to 10 . 0. at intervals of approximately 0 . 5, was used. The optimum pH was established between 5 . 1 and 6.0. Slight growth was observed on the alkaline side of this Per cent parasitism optimum, and no growth was observed in any of the plates Location having a pH value of 3 or less. Coefficient of Range Mean variability R. casearium has never been found in balsam poplar which has the same distribution as trembling aspen. It is Manitoba- suggested that the pH of the sap of balsam poplar may be Outbreak areas 1 . 2-18 . 1 6.7 83.6 inhibitory to the growth of this fungus. Peripheral areas 4 . 5-72 . 1 20.7 99.0 Experiments on the rate of decay of wood blocks at Saskatchewan- different temperatures compared with Fomes igniarius var. Outbreak areas 1 . 7- 8 . 9 4.6 97.8 populinus and Ganoderma applanatum are in progress. Other Peripheral areas 1 . 2-34 . 3 13.1 72.5 experiments on the physiological characteristics of R. casearium are also proceeding.-R. L. Black. 1Hodson, A. C. Factors affecting recovery from dispause and (1) Black, It. L. Interim Report on the decay of trembling aspen hatching of eggs of the forest tent caterpillar, Malacosoma disstria Hbn. (Populus tremuloides Michx.) in the Upper 'Pic region of Northern Minn. Agr. Expt. Sta. Bul. 170: 1-31. 1945. Ontario. Forest Pathology Laboratory, Toronto. 1951. ) W Black, R. L. Interim report on the decay of trembling aspen ZHodson A. C. Biological notes on the egg parasites of Malacosoma •„,.4 (4. tremuloides Michx.) in Manitoba and Eastern Saskatchewan. (In disstria Hbn. Ann. Ent. Soc. Am. 32: 131-136. 1939. ,7 preparation). Forest Pathology Laboratory, Saskatoon. The results of these studies indicate that a relationship exists between the per cent parasitism of egg bands and the ÿ BRITISH COLUMBIA; extent of spumaline covering. In areas outside the 1952 ;j The Mountain Pine Bark Beetle Outbreak at Winder. outbreaks where the spumaline covering appeared to be tyre Creek.-This outbreak was first reported in 1949 when lighter, egg parasitism in some cases reached levels capable oral trees were observed to be turning red, indicating of limiting the spread of tent caterpillar.-R. M. Prentice. at mortality had occurred either one or two years previously. "Red patch" Disease in Seedbeds.-A red discolora- wring 1950 and 1951, the infested area increased to include tion of white spruce seedlings (Picea glauca (Moench) Voss) approximately 2,000 acres besides several small localized has occurred;at the Big River nursery in 1949 to 1953. This groups of trees within the Windermere Creek Watershed. disease appears as conspicuous red patches in seedbeds after ring 1952, spread was limited and indications were that the snow has melted. The affected needles remain attached. the infestation was abating. to twigs and turn gradually from rusty-red to brown ands !`+ A study of the incidence of bark-beetle attack in relation grey. The disease is capable of killing needles, twigs. and' Ike stand composition, volume per acre, density in trees per small seedlings.. A whitish mould growing in snow is associ-" àdre, crown class, diameter, age, and periodic increment over ated with the disease. The number and area of red patches Ce fast twenty years was carried out in 1952. Thirty fifth- have increased every spring, especially in 1953, when 21 new* e. plots were established and silvicultural characteristics patches appeared, covermg an area of 5 square feet altogether.; . p4fi ovér 2,000 trees obtained from' these plots. The old patches have widened every spring. Experiments ÿ o correlation was found to exist between the percentage showed that the disease spreads directly from both dead and ei lodgepole pine attacked and stand composition, stand living seedlings that bear affected needles; it is capable of, density, age, or periodic increment. There was a direct advancing over a gap of 4 inches from which all seedlings correlation between percentage of lodgepole pine attacked were removed; probably by means of hyphae growing through ând volume per acre. There was also a correlation of attack snow. In an experimental plantation the disease so far has . with diameter and crown class, the larger, more dominant not spread from diseased transplants to healthy ones, although trees having suffered most severely. it persisted in the former during one year. Isolations from - Further examination of increment borings in conjunction diseased needles, stems, and snow moulds gave several fungi, with data already tabulated will be undertaken. There is some of which grow well at low temperatures (0° and 7°C.). already some evidence from microscopic examination of the 4 borings that a comparison of the summerwood with the width RECENT PUBLICATIONS of the springwood during the four or five years preceding mortality may be of importance. There are indications that Annual Report Forest Insect and Disease Survey, 1952. Canada this may be directly related to soil drought, a matter under- Dept. Agr. 1953. going further study.-G. Stuart Brown. Bergold, G. H. On the nomenclature and classification of Chemical Control of Bark Beetles.-Earlier work has insect viruses. Annals New York Acad. Sci. 56, Art. 3, indicated that DDT 25 per cent emulsion concentrate produced 1953. a higher percentage control of Dendroctonus monticolae Brown, C. E. Control of the balsam-fir sawfly in the agri- broods beneath the hark of lodgepole pine than other tried cultural areas of the Prairie Provinces. Proc. Publ. No. 2, chemicals. Nevertheless, mortality produced by DDT was Div. For. Biol. Can. Dept. Agr. 1953. neither rapid enough nor high enough to be considered Campbell, I. M. Morphological differences between the pupae adequate for reducing brood potential. During 1952 heavier and the egg clusters of Choristoneura fumiferana (Clem.) dosages of all insecticides were used in chemical control and C. pinus Free. Can. Ent. 85, 4: 134-135, 1953. experiments carried out at Windermere Creek. In the testing Foster, R. E. and A. T. Foster. Estimating decay in western of eleven insecticides on 2Z foot log sections infested with hemlock. Suggested aids to the inventory in the Queen Dendroctonus monticolae, a standard rate of 0 . 8 pounds of Charlotte Islands, Part 2. B. C. Lumberman 37 (4) : active ingredient was formulated into each imperial gallon April 1953. of 20 per cent oil in water emulsion. A blend of 0 . 6 ounce Graham, K. and M. L. Prebble. Studies of the Lecanium scale, Triton X-100 and 1 . 0 ounce Triton B-1956 was used to Eulecanium coryli (1.), and its parasite, Blastothrix sericea emulsify the oil. Aldrin, dieldrin, heptachlor, ethylene (Daim.), in British Columbia. Can. Ent. 85, 5: 153-181, dibromide, and lindane effected rapid mortality and upon 1953. final examination had killed over 90 per cent, and in some MacKay, M. R. The larvae of Choristoneura fumiferana cases 100 per cent of the broods. Technical grade DDT dis- (Clem.) and C. pinus Free. Can. Ent. 85. 4:128-133, 1953. solved in Velsicol AR 50 exhibited little bark penetrability, Smith, S. G. Reproductive isolation and the integrity of two so that early mortality was low. Later, however, the DDT sympatric species of Choristoneura. Can. Ent. 85, 4: was effective in killing over 90 per cent of the beetles as they 141-151, 1953. began to emerge. Wellington, E. F. The effect of relative humidity on the In another experiment, ethylene dibromide alone was reaction of ninhydrin with amino acids on paper chrom- tested at three concentration levels, 0 . 4, 0 . 8, 1-2 pounds of atograms. Can. J. Chem. 31: 484-487, 1953. active ingredient per gallon, and at four rates of diesel fuel oil. The lowest percentage of oil used was the minimum White, L. T. Studies in forest pathology. X. Decay of white required to take up the insecticide. The other rates were pine in the Timagami Lake and Ottawa Valley areas. 20, 50 and 100 per cent oil. All the 0 . 8 and 1 . 2 pounds per Can. J. Bot. 31: 175-200, 1953. gallon treatments caused over 95 per cent mortality. Similar Basham, J. T., P. V. Mook, and A. G. Davidson. New infor- results were obtained from the light insecticide treatments mation concerning balsam fir decays in eastern North that were formulated with 50 and 100 per cent oil. It America. Can. J. Bot. 31: 334-360. 1953. appears that the 0•8 pounds of ethylene dibromide in a 20 Bird, F. T. The effect of metamorphosis on the multiplica- per cent oil emulsion is the most satisfactory concentration tion of an insect virus. Can. J. Zool. 31: 300-303. 1953. that provides an added margin for inadequate bark coverage. Fraser, D. A. and C. A. Mawson. Movement of radioactive This preparation was also sprayed on short log sections of isotopes in yellow birch and white pine as detected with Douglas fir infested by Dendroctonus pseudotsugae. Com- a portable scintillation counter. Can. J. Bot. 31: 324-333.. plete control was effected in this small experiment. 1953. Pilot field testing is now under way at Windermere Green, G. W. and W. R. Henson. A new type of coprometer Creek in order to confirm 1952 findings under more natural for laboratory and field use. Can. Ent. 85, 6: 227-230. conditions. Only ethylene dibromide. lindane, and aldrin 1953. are being tested. The latter was chosen as representative of Richmond, H. A. Douglas fir bark beetle in B.C. British the effective chlorinated hydrocarbon group of insecticides Columbia Lumberman, 37, 5. 1953. employed last year. Smith, S. G. and D. E. Maxwell. Post-reduction of the X Although the use of systemic insecticides appeared chromosome and complete chiasma interference in the effective in earlier work, recent field testing casts doubt of Lampyridae. Can. J. Zool. 31: 179-192. 1953. their use in the control of Dendroctonus. Although they Turnock, W. J. Some aspects of the life-history and proved to be very toxic to adult beetles, field testing proved ecology of the pitch nodule maker, Petrova albicapitana disappointing. It is assumed that the failure is largely due (Busck). Can. Ent. 85: 233-243. 1953. to inadequate injection and to the disruption of the vascular Smith, S. G. Chromosome numbers of coleoptera. Heredity, system by the bark-beetle galleries.-J. M. Kinghorn. 7. Part 1: 31-48. 1953.

EDMOND CLOUTIER, C.M.G., O.A., D.S.P., Queen's Printer and Controller of Stationery, Ottawa, 1953. CANADA DEPARTMENT OF AGRICULTURE SCIENCE SERVICE-FOREST BIOLOGY DIVISION

Vol. 9 REPORT BI-MONTHLY PROGRESS REPORT Sept.-Oct. Number 5 1953 Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

SPRUCE BUDWORM SPRAYING PROJECT IN NEW BRUNSWICK, 1953 In August, 1952, representatives of Canada, the Province separation distances, were considered a spraying unit. The of New Brunswick, and four major pulp and paper companies emission rate was the same for all aircraft and was that used with operations in northern New Brunswick met to discuss in 1952 (when, for the first half of the program, aircraft flew means for saving from destruction budworm-infested forests singly, and, as the result of tests carried out at that time, of the Province. Experience gained in 1952, when 300 square employed a theoretical swath width of 100 feet and a theor- miles of forests were sprayed by New Brunswick International etical dosage of one gallon per acre). The results of the tests Paper Company with the financial assistance of the New indicated that in fairly still air, the aircraft could be separated Brunswick Government, indicated that large-scale aerial 250 feet with the certainty that their swaths would overlap. spraying operations were the only possible solution. A tenta- They also indicated that the effective swath outside the planes tive plan was adopted for the spraying of 4,000 to 5,000 square for the purpose of matching consecutive runs was of the order miles of infested forest over a period of three years at an of 75 feet per aircraft. This gave an effective swath width estimated cost of $9,000,000. The two Governments each for the unit of 400 feet and a theoretical dosage of one-half agreed to provide one-third of this cost and the companies gallon per acre. These tests were backed up by field tests undertook to bear a share of the cost on a basis to be of an operational nature under ordinary spraying weather developed in later discussions. The companies agreed to conditions. Indications were that the area missed was very provide management for the program. small; in fact, less than had been experienced with single The 1953 program as planned was for a minimum of aircraft the year before. All spraying operations in 1953 were 1,000,000 acres and was patterned closely after the Upsalquitch carried out by aircraft flying in pairs, trying to maintain a forest spraying project of 1952. separation distance between planes of 250 feet. The spraying Five airfields were constructed between September and plan had been developed with this change in technique in December 1952, and with "Budworm City" made six bases for mind and much more than the minimum target of 1,000,000 operations in the spring of 1953. acres had been delineated on maps and photographs. This The formulation used in 1953 consisted of technical DDT test is, to the knowledge of Forest Protection Ltd., the first dissolved in oil (Picco Hi-Solv #473)—one pound to one U.S. of its kind and seems to have great significance. An advantage gallon or approximately at 121/2 per cent solution by weight. which seems to stand out in this flying technique beyond that In all, 1,100,000 gallons were purchased. The formulator of safety is the rapidity with which forest areas can be delivered insecticide to railhead over a four month period— covered. This allows the sprayer to buy time when time is December to March. Sixty per cent was in drums, the very precious, even to the point where a second application remainder in bulk. All but a small part was delivered to the can be carried out on the same area in the same season. At airfields by truck or tank truck before the spring break-up. one airfield, two applications were given to an area of almost Approximately 175,000 gallons were moved to destination 250,000 acres. during the spraying operation. At three fields insecticide was The spraying plan called for an early start (as soon as stored entirely in 10,000-gallon tanks. At the three more the new foliage had flared enough to intercept the spray and remote fields, tank storage for one day's operations was pro- the insect was at a stage of development where the insecticide vided and transfer was made from drums to storage during could effect a kill). The plan as prepared was conservative spraying operations. Both systems worked well. provided ordinary weather was experienced during the develop- The application of insecticide was carried out under ment of the budworm larvae. contract, the prime contractor being Wheeler Airlines Ltd. Care was taken in advance to make the operation as of St. Jovite, P.Q., with seven aircraft. Canadian sub- safe as possible. At all fields, extreme precautions were taken contractors were Bradley Air Services Reg'd., Carp, Ont., against the occurrence of fire, both in the camps and on the with two aircraft; Leavens Bros. Air Services Ltd., Toronto, fields. Fire fighting equipment was provided wherever neces- Ont., with four aircraft; and Skyway Air Services Ltd. of sary. First aid men were present at each field and a doctor Langley Prairie, B.C., with five aircraft. The United States was employed full time during operations. All possible pre- sub-contractors were Central Aircraft Inc., of Yakima, Wash- cautions were taken to ensure safe flying. Each field had its ington, supplying fifty-seven aircraft, and Ueding Air Services own traffic pattern and a close check was kept on the perform- with two aircraft. This made a total of seventy-seven line ance of all aircraft. Fifteen mechanics were necessary to keep aircraft; all Stearman equipped with Pratt & Whitney Wasp the fleet flying. Over and above the requirement of the Junior engines of 450 h.p. Stearman aircraft (established as a reliable and comparatively In order to control' flying operations, Forest Protection safe forest spray plane) and the practice of flying in pairs, Ltd. engaged seven chief pilots, purchased one observation which in the event of accident, cuts down the necessity for plane (Stinson 108) and leased eight others. search, a helicopter stood by at the Chatham R.C.A.F. basé During the winter months, accommodation to house per- during the spraying operations in the event that rescue opera- sonnel was built, extensive aircraft servicing facilities were tions were necessary. purchased, delivered to the fields, and installed as soon as the No large forest spraying program could be launched snow disappeared. A detailed breakdown of the forest into without a reliable communications system. The New Bruns- spraying blocks was carried out and the necessary maps and wick Forest Service provided Forest Protection Ltd. with an aerial photographs provided in advance of the spraying extensive radio hook-up, linking together ten fire towers, six operation. airfields, eight observation aircraft. one motor vehicle, and The spraying fleet began to arrive at New Brunswick the Forest Protection Ltd. office. The fire towers were occu- spraying airfields about May 20th. Calibration of aircraft pied by weather observers and a very close tab was kept on was carried out within a week, and all aircraft were checked the weather at all times. and ready for spraying by May 27th. Spraying began at the The Forest Biology Division was a full partner in all earliest field on May 26th and was completed at the latest the planning that was done in advance of spraying operations field on June 30th. In 1952, spraying began on June 14th and worked very closely with Forest Protection Ltd. during and terminated on June 29th. In both instances, the work was the spraying period. Staff of the .Fredericton Laboratory completed at the beginning of pupation of the insect. handled the biological control phase of the program, were Out of experience gained in 1952 it was decided to try almost the first ones in the field, and, of course, conducted to extend the insecticide. During calibration, tests were run their own program of study during and after the spraying for swath width in which two aircraft, flying at controlled period. 77961 Plans are made to be changed, and the 1953 spraying plan method which will allow large forest areas to be covered was no exception. It is difficult to anticipate the vagaries more than once if necessary in its campaign to keep trees of the weather. After the time had arrived when spraying alive through a budworm epidemic.—B. W. Flieger, Forest could be undertaken with sonic degree of success, every Protection Ltd. advantage was taken of spraying weather; areas that had been sprayed first were watched closely by entomologists who NEW LABORATORY ESTABLISHED AT advised whether further application of insecticide was neces- MAPLE, ONTARIO sary. As the days went by and primary areas were completed and it appeared in some cases that the one application might At the Southern Regional Research Station of the Ontario produce a good result, spraying was carried over into secondary Department of Lands and Forests a new Laboratory has been areas. Almost 1,100,000 gallons of insecticide were sprayed built by that Department for the use of this Division. The over approximately 1,800,000 acres of forest, almost one- building is of brick construction, well lighted, two stories in quarter of which received a second application. height with a full basement, and has a floor space of approxi- This year, an attempt was made to save as much of the mately 19,000 square feet. Early in September, Dr. L. T. current year's foliage as possible before the insect had a White, Officer-in-Charge of the Forest Biology Laboratory at chance to destroy it completely and the entire \effort was 144 Front Street West, Toronto, moved with his sta ff to the designed to remove budworm feeding pressure from the forest. new Laboratory. On September 30th and October 1st, a The results of the spraying have been studied since the regular meeting of the Forest Advisory Committee of the beginning of July and will shortly be available. Research Council of Ontario was held in the new building Forest Protection Ltd. are very happy that this large to mark its recent completion and occupancy. There was a scale operation was carried out this year without loss of life. representative attendance both from Canada and the United Considering the number of persons involved and the amount States and, under the joint chairmanship of Dean J. W. B. of flying that was done, accidents involving aircraft were Sisam and Dr. J. E. Bier, a number of papers on various singularly few. There were six incidents: 4 accidents, 2 aspects of forest pathology under investigation in Canada aircraft washed out, no pilots hurt. were presented. In the evening Mr. W. R. Day, Lecturer in The technique used this year has resulted in a great Forest Pathology and Hygiene, of the University of Oxford, reduction in the cost of a single application. Forest Protection addressed a dinner meeting on recent developments in forest Ltd. is very much interested in working out a fast, cheap pathology in Great Britain.

CURRENT ACTIVITIES ONTARIO A nematode (identified by Dr. A. D. Baker as Panagrol- aimus sp.) was associated with damping-off at Indian Head Extensive Tree Mortality Caused by Hail in Quetico nursery. At other nurseries small pieces of seedlings which Provincial Park—In 1952, a large area in which the trees were surface sterilized by various chemicals bore nematodes were almost all dead was observed from the air in the vicinity of various species only occasionally. The common isolation of William Lake, Quetico Provincial Park, in. the Fort Frances of Panagrolaimus from heavily sterilized seedlings at Indian District. By 1953 the affected area extended eastward to Head suggests that it might be pathogenic. However, the Suzanette Lake and westward to Darky Lake, resulting in a nematode so far has failed to penetrate the seedlings grown band of dead timber a little over a mile wide and about in agar in culture tubes where no fungi were present. 10 miles long in an east-west direction. Ground observations Top drying of slow-growing, 2-year-old P. sylvestris disclosed that this mortality had been caused by a severe occurred in patches in the over-dense seedbeds (more than hail-storm that probably occurred late in the 1951 growing 150 seedlings per square foot) at Indian Head. In less dense season. seedbeds the seedlings were more vigorous and top drying Ail twelve tree species growing in the area were affected, did not occur. Several fungi, including Rhizoctonia solani, although jack, red, and white pine appeared to be most were isolated. Some vigorous 2-year-old pines showed red susceptible. Wounds on the trunks of trees were in all cases lesions on new shoots. This was probably caused by sun burn. practically confined to the western side, and twigs and Frost on June 30 damaged and killed a number of spruce branches on the eastern side and lower down on the trees transplants at Big River nursery. Frost and also some had far fewer wounds than those on the opposite side and near drought damage of spruce transplants was constantly associ- the top. No wounds were found on the 1952 and 1953 twig ated with Phoma glomerata (Corda) Wr. & Hochl. This was growth, and dissected cankers showed that two annual rings slightly pathogenic to young P. sylvestris seedlings in agar in had formed outside of the exposed cambium. culture tubes. Chrysomyxa was common but not heavy in The shape of the affected area and the periods of mor- spruce seedbeds at Big River. Experiments for controlling tality suggest that a severe hail-storm moving almost due these diseases are being conducted.-0. Vaartaja. east in the late summer or early fall of 1951 reached sufficient intensity at Darky Lake to kill the red and jack pine trees A White Trunk Rot of Poplar Caused by "Fungus A".— there by 1953, reach its peak in the William Lake area where, Investigations of decay of poplar in the Manitoulin district in some spots, practically all trees were killed by 1952, abated of Ontario revealed that a fungus of unknown identity was somewhat toward Suzanette Lake so that the trees there did associated with a characteristic type of rot. It was referred not die until 1953, and then was reduced to an intensity not to in the report as "Fungus A". severe enough to have caused tree mortality up to the present The rot occurred mainly in the trunk but in some time.—J. T. Basham. instances extended into the butt. In cross section the incipient decay is light to rusty red with an undulating margin. In longitudinal section the advanced decay column is made up PRAIRIE PROVINCES of streaks of dark red-stained firm wood intermixed with Seedling Diseases of Conifers in Saskatchewan. —Damp- el ongated pockets or columns of yellow rotten wood. Dark ing-off losses of Picea glauca (Moench) Voss, Pinus resinosa flecks may also be seen in longitudinal section. On exposure Ait., Pinus sylvestris L., and Larix sibirica Ledeb., were serious to air the stain increases in intensity until it is a very bright in Saskatchewan nurseries in the summer of 1953. Rainy orange-red colour. The rot has a faint cheese-like odour. weather may have favoured the disease: Several hundred In 1952 this fungus was found extensively in the Prairie lings showing early symptoms Provinces, but accurate figures as to its frequency could not isolations were made from seed be definitely established owing to the presence of heart rot of damping-off. Pythium., Fusarium, Alternaria, Stemphylium, Fomes igniarius var. populinus and Phoma spp. were most commonly isolated. Preliminary caused by which tends to mask inoculations suggest that Pythium isolates were very virulent the presence of other trunk rot fungi. Careful observations and probably the main cause of the disease. Rhizoctonia in the Whiteshell Forest Reserve, Man., in 1953, indicated solani Kuhn was also more virulent than the other isolates that approximately 10 per cent of living poplars are infected but it was not commonly associated with conifer damping-off. with "Fungus A" in that region.—H. L. Black. The following species of Fusarium were isolated (identifications confirmed by Dr. W. L. Gordon) : F. oxysporum Schlecth. ROCKY MOUNTAIN REGION emen. Snyder S. Hansen, F. oxysporum var. redolens (Wr.) Lodge pole Pine Mistletoe on White Spruce in Alberta.— Gordon. F. acuminatum Wr., F. equiseti (Cda.) Sacc., and In a previous note, a species of Arceuthobium was reported F. sambusinum Fuckel. Other possibly parasitic fungi that to have attacked white spruce, Picea glauca (Moench) Voss, were associated occasionally with the disease were Cylindro- in Alberta. Positive identification was postponed at that carpon sp., Pullularia spp., Botrytis sp.. Epicoccum sp., time to enable observations at flowering time of the species. Rhizoctonia sp., and Trichoderma sp. The last one was Considerabl e evidence has now beén found to indicate that tested and it proved to he slightly pathogenic to Pinus this species is the lodgepole pine mistletoe, A. americanum sylvestris in agar culture tubes. Nutt. Three species of dwarf mistletoe have been found parasitic to the larch mistletoe in all characters that are at present on spruce in the United States: Arceuthobium pusillum Peck, considered to have taxonomic value. In every case, the A. douglasii Engelm. (artificially), and A. campylopodum f. infected pine were surrounded by severely infected western microcarpum (Engelm.) Gill. Only A. pusillum has been larch, and no other mistletoe was found locally. found on spruce in Canada to date, its most western location The fact that lodgepole pine is susceptible to larch mistle- known being near Hudson Bay, Saskatchewan. toe has been known for some time. Weir successfully The following facts indicate that the mistletoe species inoculated this mistletoe on lodgepole pine, and found also involved is Arceuthobium americanum rather than any of the cases of this transfer in nature. Susceptibility of western three others mentioned above: white pine to larch mistletoe has, to the writer's knowledge, 1. The fruit of this mistletoe matures in the second not been reported. Both records are believed to be new for season after pollination. Canada.—J. Kuijt. 2. The time of flowering coincides with that of A. americanum on lodgepole pine locally (late April till early BRITISH COLUMBIA June). Report on Ambrosia Beetle Control in the Nimpkish 3. Branching, if present, is collateral rather than super- Valley, B.C.—Field trials in various parts of the world have posed. shown that gamma benzene hexachloride (BHC) confers 4. Some male flowers are supported by pedicel-like joints. considerable protection on logs exposed to attack by ambrosia '5. The size of the shoots ranges from 0 . 5 cm. to more beetles. For this purpose it has been almost unique among than 5 cm. insecticides, far surpassing in effectiveness any other chemical or combination of chemicals yet tested. During 1953 our 6. When plants are sufficiently large, pistillate flowers attention was called to a failure of BHC to protect logs in a often occur in whorls. commercial operation. We wished to determine, if possible, 7. Most shoots seem to produce more than one crop of the circumstances which might account for any failures. flowers. Following procedures which have given highly encourag- 8. The original lodgepole-pine stand surrounding the area ing results elsewhere on Vancouver Island, foresters of Cana- is heavily infected with Arceuthobium americanum. No other dian Forest Products Ltd. made several large-scale trials in species of Arceuthobium has been reported to date in Alberta. their operations in the Nimpkish Valley. Benzene hexa- The above facts seem sufficient to identify the dwarf chloride was applied in a water emulsion containing 0 . 4 per mistletoe with A. americanum Nutt. For confirmation, how- cent of the gamma isomer, at a dosage of 1 gallon per 100 ever, specimens were sent to Dr. L. S. Gill, who concurred square feet of log surface. The emulsion was made up from with our identification. a grade of BHC containing 36 per cent gamma isomer, dis- Since Arceuthobium americanum had not previously been solved in Velsicol AR 50 and rendered emulsifiable in water reported on white spruce, some description of the disease with Antarox A-400. Applications were made in three separate seems warranted. One of the most striking features of spruce areas of logging in the region. Western-hemlock and Douglas- infections is the compactness of the mistletoe brooms, often fir logs under the following conditions were treated: clear-cut resulting in a solid ball of dead needles and small branches, felled-and-bucked, right-of-way logs, and cold-decked logs. from which larger branches radiate out. These characteristics, Some treatment on nondecked logs consisted of close-range as well as the swelling produced on the main branch, serve applications on selected logs; others consisted of broadcast to distinguish the mistletoe brooms from the yellow witches' spraying over logs along a right of way. The one cold-deck broom caused by the rust, Peridermium coloradense (Diet.) given treatment was subjected to a searching spray from all A. & K., which is also common on spruce in the area. How- possible ang'es. In all applications the logs were drenched ever, as on lodgepole pine, infections are sometimes found with the BHC emulsion. The treatments began April 15 and without any evidence of broom formation. ended May 12. The mistletoe plants on spruce are usually quite small, Trypodendron sp. adults appeared in flight May 4 and 5. rarely attaining the size of the plants on pine. Curiously In most areas they were in such unprecedented abundance as enough, the ma j ority of the brooms have no external evidence to draw comment from loggers in the woods. It appears of mistletoe plants whatsoever. If plants are present at all, likely that the tremendous beetle population in one area they are minute and scarce. may have originated from great volumes of hemlock blow- down resulting from a windstorm early in 1951. Much of this The question of susceptibility of white spruce to Arccu- thobium americanum seems somewhat puzzling, since many timber produced large numbers of Trypodendron during 1951 infected pine stands in this Province have an understory of and 1952. In contrast, another area has had but very light apparently healthy white spruce. From observations at the beetle populations in recent years despite extensive logging original Kananaskis location it seems that variation in sus- for the past decade. Even the slash and stumps have had few ceptibility of spruce may occur. Here, a heavily infected attacks. It is also noteworthy that Gnathotrichus is very spruce is frequently found in close contact with a completely scarce generally throughout the valley. This is in contrast to healthy one. It is also possible that opening up of the stand other areas of Vancouver Island. increases the chances of mistletoe transfer from pine to spruce. One series of treated logs received no attacks, notwith- A quick count at the Kananaskis location showed at least 43 standing the fact that they were not treated until a whole infected spruce within an area of approximately ten acres week after the beginning of the mass beetle flights. These where all pine had been removed, but only two infected logs were in the area of extremely low population. All the spruce were found within the surrounding, severely infected, treatments in the other areas failed to give any practical undisturbed pine stand. It is hoped that inoculation tests protection despite the killing of large numbers of attacking can be made this fall to determine the degree of susceptibility beetles by the residual action of the BHC. Some Douglas-fir of local spruce to the lodgepole pine mistletoe. logs, though drenched with spray, received as many as 200 Two more cases of attack of Arceuthobium americanum attacks per 'square foot of log surface, and the beetles pro- on white spruce have since been found in the Province, one duced successful broods which eventually emerged during July. at Malign Canyon, the other at Athabasca Viewpoint, both Among untreated logs, company foresters observed, only in Jasper National Park. In both cases, only one infected those felled before March 1st were attacked during the current spruce was found among heavily infected lodgepo'e pine and season. Our own records from other areas over a period of apparently healthy spruce. Since the locations of the three years show that while Trypodendron attacks on fresher logs infections are quite separate, it seems likely that A. ameri- are less severe they nevertheless may occur during the same canum is parasitic on spruce more commonly than is known.— season, in logs felled several weeks later than the date R. J. Bourchier and J. Kuijt. indicated above. Failure of the spray to give protection for even 2 or 3 Larch Mistletoe on Lodge pole and Western White Pine. weeks could net be accounted for by leaching away with —Two more unusual hosts of larch dwarf mist letoe have been rain, .because the period concerned was dry. Even es late found. The larch mistletoe. Arceuthobium campylopodum as August 11 the logs had a strong odour of BHC. There is Engelm. f. laricis (Piper) Gill. common on western larch good reason to believe that the materials were used and (Larix occidentalis Nutt.), was found on lodgepole pine applied in a manner which has given protection elsewhere. (Pinus contorta Dougl. var. latifolia Enge'm.) at the three No satisfactory reason can yet be advanced for the failure following British Columbia localities: Cascade, west of Grand on this occasion while other tests have been highly encouraging. Forks, and Needles. Infections were fairly common, though It is evident that the attractiveness of the logs was not not abundant. appreciably affected by the chemicals used. It is possible A single western white pine (Pinus monticola Dougl.) at that the solvent is actually attractive to the beetles. It is Slocan Lake, B.C., was found heavily infected with a dwarf increasingly evident that there is much need for studies on mistletoe, also believed to be Arceuthobium campylopodum the behaviour of the beetles and of the factors which attract f. laricis. The plants on both species of pine appear identical them to loge but not to living trees. Incidental observations here also point to the need for knowledge of the overwintering the first time in British Columbia. In addition, 78 alternate habits of Trypodendron, for while they make very occasional host records new to this region and 23 records apparently attacks on logs during August, the great bulk of the popula- new to science have been determined. The survey has shown tion overwinters outside of the logs, and not necessarily in the distribution of economically important rusts, such as the the vicinity of their origin. It is not inconceivable that these broom and cone rusts of spruce and the blister rusts of pines, beetles may migrate to higher altitudes during summer, to and has led to the discovery of important rusts hitherto not redistribute themselves in unexpected areas the next spring.— known to occur in British Columbia, such as Chrysomyxa K. Graham. woronini Tranz. on spruce and cone rusts on fir (Abies sp.) and Sitka spruce. Dwarf Mistletoe on Ponderosa Pine in British Columbia. --In the United States, three species of Arceuthobium have Since tree rusts, with very few exceptions, cannot survive been found to attack ponderosa pine (Pinus ponderosa Laws.). in the absence of an alternate host and can therefore be The first, Arceuthobium vaginatum forma cryptopodum controlled by eradication of the alternate hosts, studies were (Engelmann) Gill, is a southern form, and is restricted to also extended to other host plants. Alternate hosts of 6 tree the Rocky Mountain form of ponderosa pine. The second, rusts have been discovered and the rusts' complete life cycles A. campylopodum forma typicum (Engelmann) Gill, is rela- have been determined by observation of the infected hosts tively common throughout most of the range of its host in the in the field and in the greenhouse. Over 100 inoculations were united States, and has been found up to approximately 30 performed to confirm or refute host relationships of a number miles from the Canadian border. The third, A. americanum of incompletely known tree rusts. Nutt. is found according to Gill "in rare instances only" on The preliminary survey and biological studies have indi- ponderosa pine. Apparently, dwarf mistletoe has not been cated, therefore, the nature and extent of further investigations collected on this host to date in Canada. required to clarify or increase existing information on this In May of this year, a conspicuous broom formation was important group of forest fungi. More intensive studies are noted on ponderosa pine approximately 8 miles north of in progress to provide information of the latter nature.— Kimberley, B.C. The brooms were fairly dense and of vary- W. G. Ziller. ing proportions, in one instance the entire tree being affected. On closer examination, dwarf mistletoe was found to be present in abundance on the brooms. This dwarf mistletoe RECENT PUBLICATIONS is believed to be A. americanum Nutt., for the following Cumming, Margaret E. P. Notes on the life history and reasons: seasonal development of the pine needle scale, Phenacaspis 1. The flowering time of this dwarf mistletoe coincided pinifoliae (Fitch). Can. Ent. 85: 347-352, 1953. with that of Arceuthobium americanum. Flowering times of Davidson, A. G. and W. R. Newell, Pathological determina- A. vaginatum and A. campylopodum are May-June and tion in wind-thrown balsam fir in Newfoundland For. August-September respectively, while that of A. americanum Chron. 29: 100-107, 1953. in this region is April-May. Denyer, W. B. G. Cephalosporium canker of western hemlock. 2. Accessory branches apparently had been produced from Can. J. Bot. 31: 361-366, 1953. collateral buds, and pistillate flowers often occurred in whorls. Both of these features are considered typical of A. americanum. Hottes, F. C. and G. A. Bradley. Two new species of Cinara 3. The infected ponderosa pine was mixed with lodgepole from Ontario. Proc. Biol. Soc. Wash. 66: 85-88, 1953 pine (Pinus contorta Dougl. var. latifolia Engelmann) which Muldrew, J. A. The natural immunity of the larch sawfly was infected with A. americanum. This identification was (Pristiphora erichsonii (Htg.)) to the introduced parasite later confirmed by Dr. L. S. Gill. Mesoleius tenthredinis Morley, in Manitoba and Saskatch- This collection is interesting because it represents, to the ewan. Can. J. Zool. 31: 313-332, 1953. writer's knowledge, the first record of dwarf mistletoe on Riley, C. G. Hail damage in forest stands. For. Chron. 29: Pinus ponderosa in Canada.—J. Kuijt. 139-143, 1953. Studies of Forest Tree Rusts.—The rusts represent one Ross, D. A. Key to puparia of the dipterous parasites of of the few taxonomic groups of fungi in which all members Malacosoma spp. in British Columbia. Ent. Soc. British are obligate parasites in all stages of their life cycle. A Columbia, Proc. (1952), 49: 19-23, 1953. knowledge of their physiology and ecology, geographical dis- Sullivan, C. R. Use of radioactive cobalt in tracing the tribution, host relationships, and life histories is therefore movements of the white-pine weevil, Pissodes strobi Peck. considered of fundamental and economic importance. Can. Ent. 85: 273-276, 1953. Investigations were begun in British Columbia in 1949 Sullivan, C. R. and W. G. Wellington. The light reactions to obtain information on rusts affecting forest trees. An of larvae of the tent caterpillars, Malacosoma disstria extensive survey contributing over 2,000 collections has re- Hbn., M. americanum (Fab.), and M. pluviale (Dyar). vealed 59 species of tree rusts, 14 of which are reported for Can. Ent. 85: 297-310, 1953.

EDMUND CLOUTIER, C.M.G., O.A., D.S.P., Queenls Printer and Controller of Stationery, Ottawa, 1953. CANADA DEPARTMENT OF AGRICULTURE SCIENCE SERVICE-FOREST BIOLOGY DIVISION

Vol. 9 REPORT BI-MONTHLY PROGRESS REPORT Nov.-Dec. Number 6 1953

Published by Authority of the Right Hon. James G. Gardiner, Minister of Agriculture, Ottawa

CURRENT ACTIVITIES MARITIME PROVINCES osis, stunting, poor needle retention, and are often marked by Spruce Budworm Surveys in the Maritime Provinces in dead tops, or are completely dead. 1953.—Spruce budworm surveys in the Maritime Provinces The situation in the Grand'Mére plantations appears to determining differ markedly from that in other areas under study. The consist principally of two phases. They are: (1) serious damage occurs on porous, sandy soil in pure white the present situation by aerial and ground surveys of defolia- spruce plantations. Preliminary investigation does not indicate tion of balsam fir and spruce trees, supplemented with larval direct attack by micro-organisms or insects to be responsible sampling; and (2) predicting the area of severe attack a year for the disease. in advance from the results of egg-mass sampling. Four study plots, each of about five acres, have been Completion of the first phase shows a considerable exten- set up. Two of these plots are located on rolling terrain in sion of the outbreak. In New Brunswick, it has extended 30-year-old plantations, one plot is on nearby level ground in southerly to the Southwest Miramichi Watershed, and easterly the same region, and one plot is situated on rolling land in a to the coast as far south as Cocagne. Moderate infestations 12-year-old plantation south of St. Louis de France, near occurred as far south as Albert County. Outside of the Three Rivers, P.Q. sprayed areas, larval sampling showed population increases Damage surveys of 13,600 trees, 30 years old, reveal that in most counties east of the St. John River. A new outbreak between 80 and 92 per cent of the trees must be considered appeared in Prince Edward Island. It was concentrated along lost to future utilization under present management practices. the north shore, especially between New London Bay and Some 17 to 29 per cent of the diseased trees still appear Dalvay, and between Goose River and Hermanville. Spruce, capable of recovery should the cause or causes of the injury being the predominant species in these areas, was severely be corrected in the near future. In the 12-year-old plantation, infested, but balsam fir had also lost most of its new foliage trees ranged from 0 . 5 to 14 feet in height. An average of where this species occurred in nearly pure stands. The Cape 79 per cent of the 2,640 trees examined were either dead, Breton outbreak also increased considerably in severity. This chlorotic, or less than 4 . 5 feet in height. covered a large part of the National Park and adjacent areas, Where appreciable changes in slope exist, a correlation or the northern part of the Island, which supports the only has been shown with the disease pattern. In general, the important balsam fir stands in the Province. The new foliage disease is most severe in basins. The pattern is altered, of balsam fir was almost completely stripped in many parts however, in the 12-year-old plantation where the worst damage of the highlands and some stands of spruce were severely occurs on high ground, followed in severity by depressions, attacked. A general increase in the larval population on with the best conditions consequently occurring on the slopes. spruce was noted along the north shore of the mainland of Material and data are available for determination of Nova Scotia, but defoliation was generally light. A popula- possible correlations between the disease pattern and soil tion increase also occurred on spruce trees in Newfoundland, texture, soil pH, soil temperature and moisture, soil horizons especially in the district of St. George's. The highest loss of (including an extensive hardpan layer), soil nutrients, and new foliage in this Province was observed near Stephenville toxic substances. The disease pattern suggests that the'damage Crossing and St. George's, but it did not exceed 20 per cent. may be associated with soil moisture conditions or with toxic Assuming that there will not be unusually high larval accumulations. In accordance with this observation, and work mortality between the fall of 1953 and the summer of 1954, by M. C. Rayner and W. Neilson-Jones, and by R. O. Earl, incomplete egg sampling lends some support to the following investigations of the existence and distribution of such toxic predictions for 1954. In New Brunswick, balsam fir stands substances are now in progress. severely attacked for the first time in 1953 will likely suffer Lack of available nutrients is undoubtedly an important considerable defoliation again in 1954. This includes a large factor in the damage occurring in these plantations. The part of northern New Brunswick south to approximately the trees are all situated on abandoned farm land. Where animal Southwest Miramichi and Boiestown in central New Bruns- manuring was most frequent, damage appears to be at a wick, and to Cocagne in the coastal area. Stands in some minimum. The edge effect whereby relatively good trees often eastern areas that were lightly to moderately attacked in occur along the edges of roads and fields may be due partly 1953 may show some intensification of attack in 1954, especi- to less exhausted soil and partly to drainage. This has yet ally near the east coast from Cocagne through to Albert to be investigated. It is noteworthy, however, that artificial County. Little or no change is expected west of the St. John manuring carried out in the past on experimental plots has River: The future of outbreaks in spruce stands is difficult resulted in relatively excellent growth and high survival. to predict because of inadequate study in this type of stand Furthermore, the hardpan layer has been lowered some four in the Maritime region. This is especially true in Prince feet below the level at which it occurs on adjacent areas. Edward Island, Nova Scotia, and Newfoundland. However, Mycorrhizal development is generally rather sparse, but attains in Prince Edward Island, there is evidence of renewed severe its best development where the trees are in good condition, infestations in the north to northeastern coastal areas, and and where manuring may be assumed to have occurred. Root extensions of moderate infestations covering the entire north- development is generally superficial, penetrating to depths of ern coastal area and eastern third of the Province. In Nova four or five feet only in the artificially and naturally-fertilized Scotia, considerable population increases can be expected in areas. Random observation indicates that other spruce species spruce stands along the northern part of the mainland from are affected, but not to the same extent as white spruce.— Cumberland County to the Straits of Canso. Severe defolia- Lee A. Paine. tion is almost certain to occur in all nr most balsam fir stands in Cape Breton Island, especially in the highlands. Egg sampling in Newfoundland is still in progress, but sampling ONTARIO to date indicates light populations in this Province next year. Studies of Bacillus Spp. Pathogenic for Silkworm.- —W. A. Reeks. The susceptibility of some lepidopterous larvae to infection by strains of Bacillus cereus is well known. Recent tests QUEBEC indicate that under certain conditions Anisota spp., Datana spp., Nymphalis spp., and others are also susceptible. In the Deterioration in White Spruce Plantations.—Serious development of suitable methods of testing pathogenicity, deterioration is occurring in young plantations of white spruce Bombyx mori larvae were used and it was found that they (Picea glauca (Moench) Voss) in the region centring around are quite susceptible to some B. cereus strains and particularly Grand'Mère, P.Q. Stand damage varies from openings of to Bacillus sotto, Ishiwata. A series of papers on B. sotto about one-tenth acre to a general condition where the healthy was published in Japan about 30 years ago by Aoki and trees are isolated exceptions. Individual trees exhibit chlor- Chigasaki. Concepts, techniques, and equipment developed 79831 2

since that time made it advisable to repeat some of this Nematus and Euura spend a part of their life cycle in living earlier work and their results are confirmed. plant tissue. Just prior to pupation most of the larvae have B. sotto is a variety of B. cereus which differs only been found to leave the galls and enter the ground or litter to slightly from B. thuringiensis in morphological and biochemical spin cocoons. Any method of rearing galls in the laboratory characteristics but when compared as to an LD 50 based on must, therefore, fulfil two conditions; it must prevent the viable spores, B. sotto is at least 10 times more virulent for living plant tissue from drying out and it must provide a silkworm. It causes a toxaemia which results in a paralysis, place for the larvae to spin their cocoons when they leave the onset of which may vary from 2 to 6 hours after ingestion the galls. and is dependent on a number of conditions, culture age and Large samples of gall-infested willow foliage and stems dosage being the most important. Cells from young cultures were placed in dishes 9 inches in diameter and 4 inches deep. do not exhibit this paralysing power and its occurrence is The bottom of each dish was covered to a depth of 1 inch related to the physiological age of the culture. Media com- with coarse sawdust, which was kept slightly moist. The position, incubation temperature, oxygen tension, and inoculum dishes were covered and kept at room temperature (72°F.) source all affect sporulation in a culture and in general away from the direct sunlight. Modifications of this procedure virulence is related directly to sporulation. employing 4-inch screw-cap jars have been used for small lots The toxic principle responsible for the paralysis is not of galls. Moisture gathering on the inside of dishes had to be excreted into the medium in which the organism is grown removed periodically to prevent excessive moulding. Any and if a toxic broth culture is centrifuged at high speed the mould that did form apparently did not harm the larvae supernatant is not active but the sediment can still cause providing the mould did not enter the galls. Under these infection. Toumanoff and Vago report that the supernatant conditions galls have stayed fresh for several weeks. The of centrifuged water suspensions of B. cereus var. alesti con- larvae remained healthy and were able to emerge from the tains an active principle but we have not been able to show galls when the feeding period was over. Pupation took place this in similar preparations of B. sotto. readily in the coarse, moist sawdust. The emergence of Cultures of B. sotto grown on nutrient agar were sus- adults, particularly those of Nematus (Pontania) hyalinus pended in clarified gut juice, incubated overnight, and centri- (Nort.), from, material treated this way has been quite fuged. The supernatant was filtered through an ultra-fine successful.—N. W. Watson. filter and the filtrate was found to be sterile and toxic. Similar results were obtained by treating old cultures of PRAIRIE PROVINCES B. sotto with dilute potassium or ammonium hydroxide. Leafhoppers Attaching Poplar.—A characteristic type of Hannay has recently observed alkali-soluble crystalline damage, first reported on poplar in 1952, is believed to result inclusions in sporulating cells of certain strains of B. cereus mainly from oviposition and feeding by leafhoppers. It was and generously made his results available prior to publication. first thought to be a "poplar blight" but the possibility of Because these crystals were seen only in strains known to be disease organisms being associated with the condition should pathogenic for some insects, Hannay has speculated about a not be entirely discounted. The symptoms include browning causal relationship between the crystals and the disease. of leaves and slit-like ruptures in the bark of the twigs. As A suspension of B. sotto grown on nutrient agar at 22°C. this damage is common and widespread in Manitoba and for 7 days was examined and revealed, in addition to spores, Saskatchewan, a preliminary study was conducted in 1953. crystals of the type described by Hannay. Treatment of the The following leafhoppers have been collected from poplar in suspension with 0 . 1 M NaOH resulted in the disappearance areas where the problem occurs; Idiocerus lachrymalis Fitch, of the crystals but the spores nevertheless remained viable. I. suturalis Fitch, Oncometopia lateralis F., Idiocerus sp., Although when ingested 100,000 viable untreated spores (and Macropsis sp., Oncopsis sp., and Agallia sp. an undetermined number of crystals) are capable of paralysing New oviposition damage is found on the current year's a larva in 4 hours, up to a hundred times as .many viable twigs and on twigs two to three years old; on the new growth alkali-treated spores are without effect within 36 hours. These it assumes the form of a thin, black, longitudinal ridge about treated spores, centrifuged and washed several times, are still 3 mm. long, but on the older twigs it tends to form a thin capable of causing septicaemia within 12 hours of injection slit. The eggs are about 1 mm. long and averaged eight per into the body cavity. The alkaline supernatant, rendered oviposition site examined. Old (1-2 year) oviposition damage sterile by filtration, paralyses larvae within 2 to 4 hours of assumes the shape of an elliptical bark rupture about 6 mm. ingestion but is apparently without effect 24 hours after injec- by 3 mm. This exposes the cambium and sapwood. Some tion into the body cavity. The toxic principle is not dialyz- inquilines were noted in the old ruptures. Early-instar leaf- able and is inactivated by heating for 30 minutes beyond 70°C. hopper nymphs were observed emerging from what appeared At least 5 strains of B. cereus causing paralysis in silk- to be overwintered eggs between May 23-30 at Prince Albert, worms are available at Sault Ste. Marie and all of these Saskatchewan. Nymphs were collected periodically and the produce crystalline inclusions on sporulation. They show first adults were caught on July 7. This coincided with the some difference in virulence but it is not known if this is appearance of adults reared from nymphs in cages. New quantitative or qualitative. It should be stressed that the oviposition damage was first found on August 22.—E. Smereka paralytic effect has been noted only in infected B. mori larvae, and R. R. Lejeune. for in other susceptible insect species, infected larvae are not Small Mammals as Predators of the Larch Sawfly.—It paralysed but die in a manner typical of bacterial septicaemias has been thought that the larch sawfly is extensively preyed in lepidopterous larvae. Those bacterial strains not producing upon by small mammals chiefly because the insect remains crystals are either not toxic or only weakly so "per os" for in the ground within a cocoon from mid-August until mid- silkworm larvae and the other insect species tested. Much June the following year. Theoretically there are 10 months in more work will be necessary but the production of crystalline which small mamimals can prey upon the cocoons. However, inclusions and the effect on silkworm may prove of assistance during 1952 it was found by using planted cocoons that 28 in the evaluation of newly isolated strains. per cent were taken by small mammals in the latter half of Thus, separation of toxic material from cultures of August, 41 per cent by the end of September, and 63 per cent B. sotto has been accomplished and it seems probable that by the end of October. During the period November 1, 1952 this material is associated with the crystalline inclusions to May 15, 1953, an additional 6 per cent were taken, making described by Hannay. The investigation of its nature and the total predation 69 per cent. Between May 15 and August mode of action is being continued.—T. A. Angus. 17, 1953, virtually no cocoons were taken by small mammals, but during the week of August 17 to August 24, 4 per cent of A Mutation of Eye Colour in Choristoneura fumiferana the new cocoons were taken. The percentage of predation (Clem.).—Two females and four males with scarlet-red eyes then increased to 22 by August 31, 36 by September 7, 49 by have been found this fall in two progenies of a series of sib- September 14, 78 by September 21, and 86 by September 28. matings. The normal eye has a dark purple, plum-like, colour. After the end of September, predation began to drop rapidly, The scarlet eyes are larger in size than the normal type. The the percentage of larvae consumed being 91 on October 4, larvae of the new form, up to the fifth instar, were strikingly 93 by October 11, 93 . 5 by October 18, 93 . 7 by October 25, pale and the testes were unpigmented. The males therefore and 94 . 1 by November. The greatest predation appears to could not be recognized in the third and fourth instars, which occur during September when the small mammal population normally are the convenient stages for routine determination is at its yearly peak. Predation seems to continue until freeze of sex, because of the pigmented testes. From the observa- up, after which little or no predation occurs until the following tions to date, the new mutation seems to have phenotypic August or September.---C. H. Buckner. effects similar to the eye-colour gene a in Ephestia kuehniella Z. (A. Kühn, 1930), which is caused by a single recessive ROCKY MOUNTAIN REGION gene and interferes with the metabolism of tryptophan to the dark pigment(s). (Reference: A. Kühn and •K. Henke, Spruce Budworm Head-Capsule Measurements.— During Roux'Arch. Entwicklungsmechanik, 122:204, 1930.) .—G. W. K. the course of an ecological investigation of the two-year-cycle spruce budworm, head-capsule widths were measured to Stehr. establish growth curves for the different areas under study. A Method of Rearing Saw flies from Willow Galls.—The Following is a table showing the head-capsule widths of the larvae of gall-forming sawflies belonging to the genera larvae occurring in 1952. The larvae were sexed on the presence or absence of gonads. As the characteristics used Lodge, west of Edson, the northern boundary ran east and for identification of female larvae was a negative one (i.e. north beyond Chip Lake- and then to within a few miles of the absence of male gonads), the identification was not always Edmonton, south to Gull Lake and Sundre, west to Bearberry certain, therefore, if the sex characteristic was not clear the and northeast to Rocky Mountain House. The heaviest larvae were classed as unknown. Even so, some male larvae defoliation was north of Chip Lake. The larch sawfly has probably were classified as female. This would tend to reduce extended its range in Alberta. Damage from this insect was the measured mean below the true mean of the female larvae. noted as far west as Calling Lake, Smith, and Clyde. A few An interesting point to note is that the head-capsule larvae were found at Weald, southwest of Edson, and at width of the last instar of the two-year-cycle budworm is Caroline, south of Rocky Mountain House. The heaviest much larger than that of the one-year-cycle budworm. It defoliation was at Cold Lake on the Saskatchewan border has been suggested that this may be due to the difference in where in some cases the upper third of tree crowns were com- the length of the feeding period. The feeding period is from pletely stripped.—W. C. McGuffin. 21 to 40 days in Eastern Canada, (Swaine and Craighead Decay of Subalpine Spruce on the Rocky Mountains 1924) and from 60 to 75 days in the Rocky Mountain Region. Forest Reserves in Alberta.—During 1950 and 1952 an inves- HEAD-CAPSULE MEASUREMENTS tigation of the decays and decay losses occurring in subalpine spruce, Picea glauca (Moench) Voss, P. engelmannii Parry, and P. mariana (Mill.) B.S.P., was conducted on the Rocky Mead Head Width Mountains Forest Reserves by members of the Saskatoon Instar Sex Number Measured Rocky Mt. Eastern and Calgary Forest Biology (Pathology) Laboratories. Four Budwo rm Budworm hundred and fifty-six living spruce trees on 12 sample plots (totalling 1-8 acres) distributed in the Brazeau, Clearwater, Bow River, and Crowsnest Forest Reserves were critically I Unknown 96 0.263 examined for the presence of decay. IV Female 177 0-627 0.660 An analysis of the individual trees showed that 35 per Male 121 0.625 0-635 cent were infected, cull amounting to slightly under 20 per cent of the gross merchantable volume of the sample. Butt V Female 203 1.108 1.129 infections were present in. 22 per cent of the trees examined Male 132 1.031 1-039 and approximately the same percentage of trees in the VI Female 364 1.920 1.803 sample had decay in the upper portion of the stem. Butt Male 282 1-817 1.662 infections were responsible for 35 per cent of the cull deduc- tions made for decay with the average length of the rot *Based on 1950 Annual Report by B. M. McGugan. — R. F. Shepherd. column at the butt extending 6 . 5 feet above a one-foot stump. An examination of the age-decay relations of the indi- Forest Insect Survey, Most Important Outbreaks.—A vidual trees reveals that spruce occurring in this region are total of 2,303 samples were received in 1953. These samples, relatively free from infection at 100 years, since at this age along with reports, disclosed that the important forest insects only 1 per cent of the trees were found to have decay. After of the season were the lodgepole needle miner, the forest tent 100 years there is an increasing number of infected trees in caterpillar, and the larch sawfly. the stands until at 160 years half the trees can be expected The infestation of the lodgepole needle miner, Recurvaria to possess some decay. All the trees examined over 300 years sp., in the national parks has changed but little since 1952, old were infected. except for the re-establishment of a light population in the The accompanying table summarizes the average gross bottom of the Bow Valley. The forest tent caterpillar, merchantable volumes (Scribner's Log Rule), average cubic Malacosoma disstria Hbn., occurred in spotty outbreaks over volumes, and percentage losses from decay of merchantable a great stretch of west central Alberta. From Medicine and understory trees in the immature, mature, and overmature

Average No. of Average Average Trees Grossa Percentage Age Age Class Height Tree Class 2 No. of Gross Percentage ( Total Class 1 Trees Volume Cull (Total Cuoic DecayY Total (Bd. ft.) s Sample) Volume Sample)

Immature (80-160) 2 Understory 84 14.82 7.1 184 5.33 2.1 131 3 Merchantable 27 117.51 3.1 27 27.01 1.2 140 Mature (161-200) 2 Understory 11 17.58 21.5 24 5.99 8.5 178 X1.4 4 Merchantable 22 314.17 18.9 22 60.62 9-9 185 Overmature (201 plus) 2 Understory 50 23-86 25.2 73 7-62 10.4 243 4 Merchantable 89 252.19 23.7 89 53.47 8.1 250

1 Height of tree of average volume (1) up to 30 ft., (2) 31 ft. to 60 ft., (3) 61 ft. to 80 ft , (4) 81 ft. and over. 2 Understory—trees 4" to 11" d.b.h. Merchantable—trees over 12" d.b.h. s Board foot volumes computed according to Scribner's Log Rule. Volume between stump height (1 foot) and a 4-inch top diameter inside bark. age classes. It is evident that cull losses are proportionally butt-rots are Polyporus circinatus var. dualis Peck, Flammula higher in the slow-growing understory trees, i.e. trees under connissans Fr., "Unknown C", and Coniophora puteana 11 inches d.b.h., than in the faster growing trees of merchant- (Schum. ex Fries) Karst. Fomes pini (Thore) Lloyd, which able size. Since the understory trees are also characterized was responsible for 25 per cent of the total cull, Stereum by a younger mean age this relationship might be explained sanguinolentum Alb. & Schw. ex Fries, and "Unknown M" on the basis of a differential in rate of decay or in age of are the most important causes of trunk rots.—D. E. Etheridge. infection in the two groups of trees. Both merchantable and understory trees, however, appear to enter a critical period BRITISH COLUMBIA after 160 years when the increasing rate of decay accounts for Some Aspects of Conifer Seed Micro flora.—Moulds are cull losses of 18 to 23 per cent of the average gross merchant- recognized agents of deterioration of seed under sub-optimum able volumes. storage conditions and of reduced germination of planted Thirteen of the 14 species of fungi most frequently seed, especially where germination would be delayed; at isolated from decayed wood in this investigation are referred least one common storage and soil mould has a definite to wood-destroying Basidiomycetes. Three fungi of this group pathogenic relationship with corn seedlings. still remain unidentified. Until the positive identity of the Collection, extraction, and storage of conifer seed some- unknown fungi has been established two of these have been times takes place under conditions that encourage the growth assigned to Dr. M. K. Nobles' temporary designation or survival of moulds in large numbers, measured as viable "Unknown C" and "Unknown M". The one non-basidio- spores. Assays of 23 seed samples, mostly from British mycetous fungus which has been most frequently isolated Columbia, showed that many commercial lots of conifer seed from decayed wood is thought by Miss Doreen Wells to be have a large number of viable moulds, up to 10,000,000 per the imperfect form of Coryne sarcoides (Jacq.) Tul. It is gm. The assays failed to show close correlation between high not known, however, whether this fungus is capable of de- mould content and low viability of seed. This is attributed, stroying wood. in part, to the fact that the seed samples were of various ages. In order of their importance as wood-destroyers in this It has. been observed that, on some species of conifers, region the fungi most frequently ,isolated from root- and the immediate injury to seed resulting from moulding does not appear to be great. This is probably because of the volume was lost through the action of decay. In the larger protection given by the relatively heavy seed coats. The diameter classes, the decay losses remained high but de- microscopic examination of apparently undamaged seed creased from 90 per cent in the 25-inch class to 59 per cent showed that mycelium was present in the outer layer of cells in the 50-inch class. of the hard seed coats. Mycelium was not observed in the The average depth of radial penetration has not been inner papery seed coats in the samples examined. Cultural determined to date. While taking field data, however, it was tests were carried out of dissected seed surface sterilized with noted that the depth varied considerably in trees of the same 0 . 1 per cent mercuric chloride for 5 minutes. Fungi were diameter as well as in trees of different diameters, but in all isolated from kernels with and without corresponding isola- cases increased toward the tops which were mostly 100 per tion from seed coats. cent decayed. This evidence suggests that moulds may penetrate Brown crumbly rot, caused by Fomes pinicola (Sw.) Douglas-fir seed and may occur both externally and internally. Cooke, the principal decay found associated with the deteri- These findings appear to substantiate the following statement oration of the looper-killed hemlock, accounted for 87 per of Davis, Wright, and Hartley: "Organisms that may cause cent of the recorded decay volume. Yellow stringy and white decay after the seed is sown are sometimes found inside the spongy rots were responsible for most of the remaining decay seed coats of apparently sound, stored seed." volume which was confined primarily to the lower sections In the mould assays made, the fungi most commonly of the butt logs. The principal fungi associated with these found were Penicillium spp., Mucor spp., Aspergillus glaucus latter rots have been tentatively identified as Armillaria Lk., and Pullularia sp. Within these four groups, five out of mellea (Vahl ex Fr.) Quél. and Fomes annosus (Fries) Cooke. six isolates of Aspergillus glaucus did not grow at 5° C., but Pitted saprot, caused by Polyporus abietinus Dicks. ex Fries, almost all the 18 isolates tested from the other three groups was noted in the sapwood of some of the trees but not in did. Thus, some of the more common seed moulds can grow measurable quantities, although in the earlier examinations at temperatures comparable to those under which conifer seed this fungus was one of the more important saprots. Several is usually stored in British Columbia. Growth of moulds other fungi, still unidentified, were also isolated from the would not be expected, however, in conifer seed stored at a affected trees, but the volume of decay associated with them moisture content of 8 (per cent or less.—P. J. Salisbury. was generally insignificant.—N. T. Engelhardt. Deterioration of Looper-killed Western Hemlock on Lower Vancouver Island.—During 1945 and 1946 extensive RECENT PUBLICATIONS stands of mature western hemlock on lower Vancouver Island Davis, J. M. and K. R. Elliott. A rapid method of estimating were attacked by the western hemlock looper. As a result, aerial spray deposits. J. Econ. Ent. 46: 696-698. 1953. these defoliated stands suffered heavy mortality and thus Denyer, W. B. G. and C. G Riley Decay in white spruce at became subject to pathological deterioration. Since informa- the Kananaskis Forest Experiment Station. For. Chron. tion was lacking in regard to the deterioration of such timber, 29: 233-247. 1953. a series of periodic examinations were undertaken by the Evans, David. Field key to Geometrid larvae of the British Forest Pathology Laboratory at Victoria, B.C., to determine Columbia coast. (Multigraphed publication). the rate of decay of these stands and the identity of the Foster, R. E. and A. T. Foster. Estimating decay in western causal fungi. Three such examinations have been made, the hemlock. III. Suggested aids to the management of first in 1948, the second in 1950, and the third and final in mature hemlock-spruce forests on the Queen Charlotte 1953. This report presents a brief summary of results obtained Islands. British Columbia Lumberman 37, No. 10. 1953. to date from the final analysis. Greenidge, K. N. H. Further studies of birch dieback in Fifty-five hemlock, ranging in diameter from 12 to 50 Nova Scotia. Can. J. Bot. 31: 548-559. 1953. inches, were analysed on a representative 1-acre rectangular McGinn, W. K. and A. G. Davidson. Studies on white pine plot in a 100 per cent looper-killed stand in the Wilson Creek blister rust in Nova Scotia. For. Chron. 29: 267-272. area. Although all the trees were standing, none had retained 1953. • their tops and only a few had retained any of their branches. Reeks, W. A. The establishment of introduced parasites of In many cases a sizable portion of the upper bole was also the European spruce sawfly (Diprion hercyniae (Htg.)) missing. These losses, estimated to average between 5 and in the Maritime Provinces. Can. J. Agr. Sci. 33: 405-429. 10 per cent of the original gross volume, were attributed to 1953. the combined action of weathering, principally wind and Smith, C. C. Control of the winter moth on shade trees. snow, and weakening by fungi and insects. Can. Dept. Agr. For. Biol. Div. Processed Publ. No. 3. The total volume of decay, excluding that occurring in 1953. the trees prior to their death, measured 74,278 board feet or Smith, S. G. A pseudo-multiple sex-chromosome mechanism 66 per cent of the total gross volume. Eighty-five per cent in an Indian gryllid. Chromosoma. Bd. 5: 555-573. 1953. of the decay volume was recorded as advanced decay and Thomas, G. P. and D. G. Podmore. Studies in forest pathology. 15 per cent as incipient decay. In the lower diameter XI. Decay in black cottonwood in the middle Fraser classes, 20 inches and under, almost the entire merchantable region, British Columbia. Can. J. Bot., 31: 675-692. 1953.

EDMOND CLOUTIER, C.M.G., O.A., D.S.P., Queen's Printer and Controller of Stationery, Ottawa, 1954.

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