Forest Insect and Disease Conditions Vancouver Forest Region • 1992 Rod Turnquist and Dennis Clarke

FIDS Report 93-6

Forestry Forêts lel Canada Canada Canada Table of Contents

Page

FOREWORD 3 INTRODUCTION 4 SUMMARY 4 DOUGLAS-FIR PESTS 7 Western spruce budworm, Choristoneura occidentalis 7 Douglas-fir beetle, Dendroctonus pseudotsugae 10 Douglas-fir tussock moth, Rusty tussock moth, Orgyia pseudotsugata, 0. antiqua badia 12 Laminated root rot, Armillaria root rot, Phellinus weirii, Armillaria ostoyae 13 Abiotic damage 14

PINE PESTS 14 Mountain pine beetle, Dendroctonus ponderosae 14 Pine sawfly, Neodiprion nanalus contortae 15 European pine shoot moth, Rhyacionia buoliana 17

SPRUCE PESTS 17 Spruce beetle, Dendroctonus rufipennis 17 Spruce weevil, Pissodes strobi 17 Spruce aphid, Elatobium abietinum 18

TRUE FIR PESTS 18 Western balsam bark beetle, Dryocoetes confusus 18 Balsam woolly adelgid, Adelges piceae 18 Needle blights, Isthmiella sp., Phaeocryptopus nudus 19

CEDAR PESTS 19 Cedar leaf blight, Didymascella thujina 19 Cedar flagging 19

HEMLOCK PEST 19 Western blackheaded budworm, Acleris gloverana 19

SPECIAL SURVEYS 21 Pinewood nematode, Bursaphelenchus xylophilus 21 Acid rain plots 21 Pests of young stands 23 Seed orchards 23

DECIDUOUS TREE PESTS 26 Gypsy moth, Lymantria dispar 26 Winter moth, Operophtera brumata 26 Cottonwood sawfly, Nematus currani 27 Bigleaf maple scorch and leafspots, Xylella fastidiosa, Rhytisma punctatum, Cristulariella depradens 27 Western winter moth, Erranis tiliaria vancouverensis 28 Dogwood leaf blight, Discula destructiva 28 Birch leafminers, Fenusa pusilla, Profenusa thomsoni 29 Fall webworm, Hyphantria cunea 29 Jumping gall wasp, Neuroterus saltatorius 29 An oak leaf phylloxeran, Phylloxera sp. near glabra 30

NEW RECORDS OF OCCURRENCE AND DISTRIBUTION 30

OTHER NOTEWORTHY AND MINOR PESTS 31

QUEEN CHARLO FIE ISLANDS

SUMMARY 33

HEMLOCK PESTS 33 Western blackheaded budworm, Acleris gloverana 33 Hemlock sawfly, Neodiprion tsugae 34 Hemlock dwarf mistletoe, Arceuthobium tsugense 34

SPRUCE PESTS 34 Spruce aphid, Elatobium abietinum 34 Cooley-spruce gall adelgid, Adelges cooleyi 35 Spruce needle blight, Lirula macrospora 35 Large-spored spruce-Labrador tea rust, Chrysomyxa ledicola 35

PESTS OF YOUNG STANDS 35

MINOR PESTS 37

APPENDICES 39 Foreward

Forest Insect and Disease Survey (FIDS) is For the Vancouver Island district: a nation-wide network within Forestry Canada with the responsibility of: (1) producing an Forest Insect and Disease Survey overview of forest pest conditions and their Forestry Canada implications including predictions where possi- Kye Bay, R.R.#1 ble; (2) maintaining records and surveys to sup- Comox, B.C. port quarantines; (3) supporting forestry V9N-5N1 Ph. 339-4722 research with field studies, records, Herbarium and Insectary collections; (4) providing advice For the Queen Charlotte Islands: and extension on forest insect and disease conditions; (5) developing and testing survey tech- Forest Insect and Disease Survey niques; (6) and conducting related biological Forestry Canada and impact studies, Box #23, Terrace, B.C.

During the year, correspondence and V8G-4A2 Ph. 635-7660 inquiries regarding forest pest problems, and requests for publications can be directed to For the Bella Coola/Mid-Coast area: FIDS headquarters at: Forest Insect and Disease Survey Pacific Forestry Centre Forestry Canada Forestry Canada Sidcum sub., Comp. 33, R.R. #3 506 West Burnside Road Williams Lake, B.C. Victoria, B.C. V2G-1 M3 Ph. 392-6067 V8Z-1 M5 Ph. 363-0600

During the field season, May to October, inquiries can be directed to the FIDS field sta- tions.

For the Vancouver Mainland district:

Forest Insect and Disease Survey Forestry Canada P.O. Box 692 Agassiz, B.C. VOM-1A0 Ph. 796-2042 The Queen Charlotte Islands section, Introduction included seperately in this report, was submitted by the Prince Rupert west FIDS Ranger, John This report outlines the status of forest pest Vallentgoed. The annual survey of the Queen conditions in the Vancouver Forest Region for Charlotte Islands was conducted from July 13 to 1992 and forecasts population trends of some 24. Insect and disease data from the Mid-coast Forest District was collected by Cariboo FIDS potentially damaging pests. Pests are listed by host in order of importance with emphasis given Ranger, Bob Erickson. FIDS insectary biologist, to those capable of sudden damaging out- Robert Duncan contributed to the sections on breaks. Most of the information was gathered the oak leaf phylloxeran and the jumping gall wasp as well as providing information on the through the monitoring of already known or recently reported insect or disease problems; winter moth situation in the Greater Victoria the detection of pest problems through travels area. The FIDS pathologist/mycologist Dr. through the region; annual aerial surveys during Brenda Callan contributed to the bigleaf maple scorch and leafspot section. The author wishes which major pest problems are mapped for area and severity; and several special surveys and to acknowledge the support of the British Columbia Ministry of Forests which assisted collections. with air transportation and Scott Paper Ltd., Special surveys carried out during the field which assisted with ground transportation and season included: inspections of provincial parks, defoliator and disease sampling. ecological reserves, seed orchards and acid rain Defoliation intensities are referred to a num- plots; pheromone trapping of spruce budworm, gypsy moth and Douglas-fir tussock moth; ber of times in the report are defined as follows: Douglas-fir tussock moth egg mass surveys; Trace - evidence of feeding barely poplar pest surveys; young stand surveys; detectable close up European pine shoot moth and pine shoot beetle Light - some branch and/or upper crown surveys at Christmas tree farms and; pinewood defoliation, barely visible from the air nematode surveys at log sort yards. Additionally, Moderate - pronounced discoloration and many enquiries from public and industry were noticeably thin foliage, severe top defoliation investigated with pest identification and, where Severe - top and many branches completely possible, control advice provided. Cooperation was also extended to a graduate student from defoliated, most trees more than 50% defoliated Simon Fraser University doing pheromone trapping studies on the western hemlock looper. Summary Special collections made during the field season included woodborers and woodborer infested material, pinewood nematode samples, This summary of pest conditions in the cottonwood sawfly larvae, maple leaf scorch, Vancouver Forest Region in 1992 includes a Douglas-fir tussock moth larvae, spruce weevil summary of weather conditions and lists the infested leaders, and worms. These collections most damaging pests, generally in order of contributed to current and continuing studies at importance by host affected. the Pacific Forestry Centre and other research institutes. The winter of 1991-92 and the 1992 growing season were marked by noticeably warmer The forest pest survey field season extend- than normal temperatures. Mean tempera- ed from early May to late September. One hun- tures at the Vancouver, Victoria, and Port Hardy dred and sixty insect and 140 disease collec- Airports from October 1991 to March 1992 were tions were submitted to the Pacific Forestry warmer than the 30 year (1951-80) average by Centre by FIDS personnel. Figure 1 shows the 21, 21, and 19% respectively. Temperatures at locations where samples were collected and the these locations from April to September 1992, area covered by 11 hours of fixed-wing aircraft (considered to be the growing season) were surveys. warmer than the 30 year average by 8, 7, and VANCOUVER FOREST REGION

0 40 80 km

FOREST INSECT AND DISEASE SURVEY

Figure 1. Locations where one or more forest insect and disease samples were collected and areas covered by aerial surveys to map bark beetle and defoliator infestations in 1992. 8% respectively. These warmer temperatures Balsam bark beetle killed mature alpine fir probably contributed to the marked increase in over 625 ha, down from 1105 recorded in 1991, defoliator populations and resulting damage mostly in the Fraser TSA. New balsam woolly seen regionally this year. adelgid quarantine zone boundaries have offi- cially been adopted. Also, populations and Western spruce budworm lightly to damaged trees were found for the first time on severely defoliated mostly Douglas-fir over Lasqueti Island. Needle blights were 21 130 ha, an almost fourfold increase from the widespread on amabilis fir near Sayward on 5850 ha recorded in 1991. Defoliation increased Vancouver Island and in watersheds in greater in most previously infested stands in the Vancouver. Birkenhead River area and expanded significantly up the Lillooet River valley north of Western blackheaded budworm popula- Pemberton. New areas of defoliation were also tions remained at endemic levels following their mapped in the Nahatlatch River valley near collapse last year. Boston Bar. Top-kill of up to 3m was recorded on up to 40% of trees in areas that have suf- Cedar leaf blight infections were similar to fered repeated defoliation. Although the area of those recorded in 1991 while the incidence of Douglas-fir beetle attacks declined to 170 ha cedar flagging increased. from 240 ha recorded in 1991, the number of infestations increased to 210 from 57 in 1991. Pinewood nematode surveys concentrat- Douglas-fir and rusty tussock moth popula- ed on western hemlock and its susceptibility to tions in the Fraser Valley collapsed by mid-sum- attack by sawyer beetles. Assessments at 10 mer in the third year of high populations. Some acid rain national early warning system light to moderate defoliation was recorded (ARNEWS) plots in the region found no evi- before the collapse. A nuclear polyhedrosis dence of acid rain damage. Additionally, one virus (NPV), along with direct control action at new ARNEWS plot was established in the two golf courses, contributed to the collapse. Vancouver region. Fifteen seed orchards were Root rots, a common and ongoing widespread visited at least once for the detection of pests, problem in both young and mature stands, were some of which included balsam woolly found in various locations region-wide. Multiple adelgid, cooley spruce gall adelgid, and the tops resulting from previous winter-killed termi- hemlock woolly adelgid. A total of 36 young nal buds were recorded at several locations in stands were surveyed for pest problems, two of the southwestern part of the region. which were abiotic damage and needle diseases. Mountain pine beetle killed an estimated 15 000 trees over 775 ha in 152 infestations, up from Gypsy moth traps were placed at 105 loca- 7000 trees over 465 ha in 71 infestations in 1991. tions by FIDS staff throughout the region. Three Most mortality continues to occur in the Soo adult males were caught in traps placed in the Timber Supply Area (TSA). Pine sawfly caused lower mainland. As well, about 163 adult males moderate to severe defoliation in a 15-to 20-year- were caught in traps placed by Agriculture old stand at Spuzzum Creek, northwest of Yale. Canada in various locations on Vancouver There was no further recorded spread of Island and the lower mainland. All of these European pine shoot moth populations in native adults were European, no Asian biotype adults trees at Richmond. Infested Scots and Austrian were trapped this year. Winter moth popula- pine were found in the same general area. tions increased on the lower mainland causing patchy light to moderate defoliation in, widely Spruce bark beetle populations remained scattered areas. Damage on Vancouver Island low for the seventh consecutive year. About remained similar to last year. Western winter 2 ha of recent mortality were recorded in the moth populations collapsed, there was no Mid-Coast Forest District. Spruce weevil popu- recorded defoliation at any previously infested lations continued to cause significant leader mor- sites. Severe scorching of Garry oak by the tality throughout the host range. Spruce aphid jumping gall wasp in the the Capital Region populations increased, causing widespread light continued for the seventh consecutive year. to severe defoliation in coastal areas. Damage was also reported for the first time near Duncan and Nanaimo. Oak leaf phylloxeran Defoliation continued at levels higher than or spread to Comox, but damage levels in Greater similar to 1991 in the Haylmore-Spruce-Eight Victoria remained similar to those recorded last Mile creeks area and in the Birkenhead-Gates year. Defoliation by a cottonwood sawfly on rivers and Sockeye Creek areas while declin- islands in the Fraser River in the Chilliwack- ing slightly in the Blackwater-Phelix creeks Agassiz area increased to 685 ha of light to area (Table 1). These latter areas are the severe damage, up from 50 ha recorded in some of oldest defoliated during this outbreak. 1991. Dogwood leaf blight infections continued at moderate to high levels throughout the In the Fraser TSA, defoliation increased host range. The incidence and intensity of and was recorded in several new locations. bigleaf maple scorch and Ieafspot increased New defoliation, consisting of two patches of in lower mainland areas while remaining similar mainly light and one small area of severe, were to levels recorded last year on Vancouver recorded near Hannah and Francis lakes. One Island. Fall webworm populations continued new area of light defoliation was seen on south- at high levels throughout the region, especially west facing slopes above the Nahatlatch River in the upper Fraser Valley. in the Four-Barrel main area. A very small area of light defoliation was again recorded near A table summarizing other noteworthy Hannah Creek. and minor pests is included in this report, as well as a summary of occurrences of new The 21 130 ha recorded this year is both records in the region. the largest area defoliated, and the first time that severe defoliation has been recorded during this current outbreak, which is in its seventh Douglas-fir Pests consecutive year (Figure 3).

Damage Spruce budworm Choristoneura occidentalis Although no tree mortality has been recorded during this current infestation, cumulative The area of western spruce budworm-dam- top-kill on both mature and younger douglas-fir aged Douglas-fir increased almost fourfold to was observed. Top-kill was most evident in 21 130 ha in 47 pockets from 5850 ha in 23 areas where defoliation has been recorded for areas in 1991 (Figure 2). There were 14 230 several years, mainly in the SOO TSA. Areas ha of light, 5420 ha of moderate, and 1480 ha of where top-kill was noted included North Creek, severe defoliation. 40% of semi-mature trees with 1-3m top-kill; Blackwater Creek, up to 1m on 20% of young to Defoliation semi-mature trees; Eight Mile Creek, approximately 2-3m top-kill on up to 50% of young to The area and intensity of defoliation semi-mature trees, worse on understory trees; increased in most previously defoliated areas and Birkenhead River (Fowl Creek), up to m in the Soo TSA. New areas were recorded in top-kill on approximately 10% of semi-mature patches up the Lillooet River valley from the and mature trees. Johnny Sandy Creek area on the northeast side of the valley near Pemberton through the Defoliation was also recorded in young Railroad-North-Pebble-Salal creeks area stands that had recently been spaced. Light almost to Silt Lake at the head of the valley. defoliation was recorded in one stand near Some defoliation was also recorded on the Blackwater Creek and was reported in stands in southwest side of the valley at South, the Birkenhead River-Tenquille Creek area, Meagher, and Manatee creeks. The North while moderate to severe defoliation was Creek area was defoliated last year, however, observed near Eight Mile creek. Growth loss the rest of these areas were newly defoliated and top-kill will result from repeated defoliation in 1992. Defoliation in the upper valley near in these younger, higher value, spaced stands. Pebble, Salal, and Manatee creeks was mod- Some budworm larvae were also noted in plan- erate to severe, and mostly on amabilis fir. tations adjacent to defoliated stands. Near

VANCOUVER FOREST REGION

0 40 80 km

C AAA P B E L..L NNE' ,„,E ,,,,,4 1- CE'rN E..„-, L. L F?? „LER NIS L F N y I ,,,, = 17— , E L 7 rEN- \ \lo.A i , - 4 ,;",1, "z„:1 "„t,..L .iD ti F:LI. EN AY lik) ,E-L-70 77/741,1- . ft:4 it :: „t,,, . , \ ., ,,, st, \\ ,i,""1.• N . , . i 1 12 ,..... . /Ai • ddddd d g

ca • • --- - -, ,A=j i • ) 7 .A BPEC 7 1". ---‘-- VAN C CI ti V E N t-;=-.1 lt - • ,. _EN

N A N A M 0 Y 'w , N /rrk3,7 w • F-, w , ni

plei). V i C TO R I A FOREST INSECT AND DISEASE SURVEY

Figure 2. Areas where current defoliation by the Western spruce budworm was detected during ground and aerial surveys in 1992. Figure 3. Area of Douglas-fir defoliated by Western spruce budworm during current outbreak, 1986-1992, Vancouver Forest Region.

Blackwater Creek, 90% of 1-to 2-year-old increasing populations continued in 1992; how- seedlings suffered trace feeding, as did 10% of ever, the larval sampling phase was dropped. newly planted seedlings near Hannah Creek. Pheromone-baited dry "Multipher" traps were These seedlings should not be affected by placed (5/site) in each of four areas of previous minor feeding, however, repeated moderate to infestations - Devine, Skagit Valley, North Bend severe defoliation could result in growth loss and Anderson River - to attract male adults and leader/stem deformities. (Table 3). While the average number of moths per trap increased at all four sites, only trace Based on previous outbreaks, the incidence defoliation was recorded at two sites. of top-kill will continue as long as the infestation does, and probably even after the infestation This is the second consecutive year of subsides. Increment cores taken in 1989 in increasing moth catches at 3 of the 4 sites, how- lightly to moderately defoliated stands showed ever, higher numbers of moths were recorded in an average 12% growth loss. the late 1980s at 3 of the 4 sites (Figure 4). Even with high numbers of moths recorded in Forecast the late 1980s, only light (1 988-90) or trace (1987,91,92) defoliation has ever been record- An average of 50 egg masses/10m2 of ed at the Devine site. Also, this is the first year foliage (range 35-73) were collected at 7 loca- that any defoliation has been recorded at the tions, 6 North of Pemberton and 1 near Boston Anderson River site. Bar, down 43% from an average of 81 (range 21-174) in 1991 (Table 2). Despite declining All locations where more moths were populations, defoliation is predicted to continue, caught in 1992 than in 1991 will be monitored mainly at light levels, in 1993. closely next year, particularly the Anderson River site. Calibrating the traps to relate the The pheromone trapping portion of a bud- number of moths to defoliation will take at least worm sampling project started in 1987 to detect another year. Table 1. Defoliation of Douglas-fir by western spruce budworm, from aerial surveys, Vancouver Forest Region, 1992 and 1991.

Area of defoliation (ha) Light Moderate Severe Total Tsa and location 1992 1991 1992 1991 1992 1991 1992 1991

SOO TSA

Birkenhead R. 1 420 470 800 720 2 220 1190 Blackwater-Phelix 860 1320 860 1320 creeks Spruce-Haylmore- 2 200 720 420 2 620 720 Eight Mile creeks Birkenhead Lk.- 540 960 1310 1 850 960 Sockeye creek Gates River 780 500 110 - 780 610 Lillooet River 8 090 650 2890 380 1450 12 430 1030

FRASER TSA Hannah Creek- 50 20 50 20 4 Barrel main Hannah-Francis 290 30 320 lakes

Total 14 230 4640 5420 1210 1480 21 130 5850

Douglas-fir beetle killed timber was mapped in 1991. Several spot Dendroctonus pseudotsugae infestations were recorded along the east side of Lillooet River and Lake, from Rogers Creek to For the second consecutive year the area Joffre Creek including a number of small infes- containing recent beetle-caused Douglas-fir tations still occurring in the Twin One and Two mortality decreased to 170 ha in 210 infesta- creeks area. A few small areas were also tions from 240 ha in 57 infestations in 1991. mapped in the Birkenhead River and Gates While the area was reduced the number of Lake areas. small, 1-5 tree, infestations increased through- In the Fraser TSA, the recorded area of out the region. Most of the mortality continues beetle-killed timber was 140 ha in 175 infesta- to occur in the Interior Douglas-fir Bio- tions, compared to 145 ha over 44 infestations geoclimatic Zone near Pemberton and Boston in 1991. Although the area was virtually the bar. same, the number of infestations increased The biggest decrease occurred in the Soo fourfold. Most of the area and over half the TSA where the area of beetle-attacked infestations were seen along the Fraser River Douglas-fir declined to 30 ha in 35 infestations and associated side drainages between Yale and the mouth of the Nahatlatch River. The from 95 ha in 13 infestations. There was no recent mortality seen along the west side of number of infestations in the Anderson River Lillooet Lake opposite Lizzie and Twin One area increased, with several new spot infesta- creeks where almost 75% of the area of beetle- tions south of the fork of the East Anderson Table 2. Predicted 1993 spruce budworm defoliation based on egg counts, Vancouver Forest Region, 1992.

Avg. no. of egg masses/10m2 of foliage/plot Defoliation1 %increase/– Location 1992 1991 decrease 1992 1993(predicted)

Soo TSA Birkenhead R. 60 174 -66 Moderate Light-moderate 8-Mile Cr. 46 119 -61 Moderate Light Haylmore Cr. 35 28 +25 Light Light Blackwater Cr. 38 21 +81 Light Light North Cr. 47 92 -51 Light Light Salal Cr. 73 new Light-moderate Light-moderate

Fraser TSA Hannah Cr. 49 new Light Light

Average 50 87 -43

1. 1-50 egg masses/10 m2 = light defoliation 51-150 egg masses/10 m2 = moderate defoliation 151+ egg masses/10 m2 = severe defoliation

Table 3. Comparison of 1992 and 1991 pheromone sampling results at spruce budworm calibration plots in the Vancouver Forest Region, 1992.

Avg. no. moths/trap average defoliation at plots Location 1992 1991 1992 1991

Soo TSA Devine 306 150 trace trace

Fraser TSA North Bend 127 94 none none Anderson R. 257 49 trace none Skagit Valley 16 4 none none

Average of 4 traps, one destroyed. TS O E O zE

57 49 20 25 I 28 21 18 16 .... .11 _ 6 Li 0 1 6 4 1,4,46019 NAAASSN°53%, NctAce Devine North Bend Anderson River Skagit Valley

Figure 4. Comparison of pheromone sampling results at four spruce budworm calibration plots from study inception to date, 1987-1992, Vancouver Forest Region.

River, and between the Anderson and Utzulis about 5 ha of windthrown Douglas-fir were rivers east of Boston Bar. There was also an mapped on Bowen Island. increase in the number of small spot infestations in the Fraser Canyon between Yale and Populations are expected to remain at simi- Boston Bar. About 40 small infestations were lar levels for 1992. The beetle prefers material mapped in the Chilliwack River valley, includ- such as felled trees, slash (over 20 cm diameter), ing several new areas along Foley Creek, stumps, overmature trees, and trees damaged by southeast of Chilliwack. Several small areas drought, root rot, logging and road building. were mapped in the Skagit Valley area from Maselpanik Creek to Ross Lake, with a few spots along the Skagit River south of Manning Douglas fir tussock moth Park. Three areas totaling 15 ha were mapped Orgyia pseudotsugata on the northeast side of Sumas Mountain Rusty tussock moth where beetle populations appear to have built Orgyia antiqua badia up in windthrown timber along cut block boundaries before attacking standing timber. Two The outbreak in the Fraser Valley, which small patches of beetle-killed trees as well as continued for the third consecutive year causing mainly light to moderate defoliation in scattered Forecast locations, appeared to have collapsed by late summer. Immature Douglas-fir were lightly Five pheromone-baited sticky traps were defoliated along the Trans-Canada Highway in placed in the Abbottsford-Clearbrook area and 5 the Abbottsford-Clearbrook area and moderate- west of Chilliwack, to monitor adult male moths ly defoliated west of Chilliwack. Some light and and as an aid to predicting the population next occasionally moderate defoliation also occurred year. No Douglas-fir tussock moth, and only an at the Chilliwack Golf and Country Club south- average of 1.5 (range 0-4) rusty tussock moth west of Chilliwack and at the Meadowlands Golf caught in the traps. Egg mass surveys conduct- Club east of Chilliwack. ed at the Chilliwack Golf and Country Club were also negative. The presence of virus, the Btk A nuclear polyhedrosis virus, NPV, which spray, and the negative pheromone trap and killed 25% of a mass collection made in late June egg mass surveys all point to a population col- is probably responsible for this collapse. Two pre- lapse. The area will be monitored in 1993, how- vious outbreaks, which occurred in the same gen- ever, no defoliation is expected. eral area in the Fraser Valley in 1971-72 and 1982-83, were also suspected to have collapsed Laminated root rot from virus. Another factor in the collapse were Phellinus weirii two late spring applications of Bacillus thuringien- Armillaria root disease sis, var. kurstaki, (Btk), at the Chilliwack Golf and Armillaria ostoyae Country Club. High egg mass numbers were detected at this location during an early May egg These two root rots are chronic problems mass survey. The survey was prompted by high and were commonly found in both young and numbers of adults caught in pheromone-baited mature Douglas-fir stands throughout the traps placed near the golf course in 1991. The Vancouver region in 1992. high numbers of egg masses prompted the golf course to take control action. This is the third time Laminated root rot, P. weirii, killed semi- in the last 15 years that the golf course used mature and mature trees in the following areas; insecticides to control tussock moth outbreaks. Read Island, Bowser, Black Creek, Saltspring Additionally, the Meadowlands Golf Club east of Island and the UBC Research Forest near Chilliwack used ORTHENE by aerial application Maple Ridge. The root rot is widespread to control the tussock moth. throughout the Fraser Canyon and Anderson River areas where Douglas-fir beetle attacks are Damage associated with stressed trees.

Damage to scattered individuals ranged from Tree mortality from armillaria root disease, light defoliation of a few branches to about 30- A. ostoyae, averaged 2% (range 1-2) in young 40% of the crown defoliated. A group of about stands at Oktwanch River and Nahwitti Lake on 10 immature Douglas-fir west of Chilliwack on the Vancouver Island and Chipmunk Creek near south side of the Trans-Canada Highway were Chilliwack. Armillaria was also found in recently almost completely defoliated this year after suf- dead immature trees in the UBC Research fering about 60% defoliation and about two Forest. metres top-kill in 1991. These trees were removed by the Highways Department by early Mortality from these diseases is perennial, fall. At the Chilliwack Golf and Country Club, occurs in many more areas and sometimes at about 25% of mature Douglas-fir were lightly, and greater intensities than are listed above, and will a few trees moderately, defoliated. This defolia- continue to occur throughout the range of tion occurred despite two aerial applications of Douglas-fir. Planting root rot resistant tree Btk. Some of these trees appear to have up to species, including some hardwoods, in areas m or more of top-kill. Recovery of these trees where severe problems occur is one of several will be monitored in 1993. The few trees lightly management tools used to lower root rot losses. defoliated in the Abbottsford-Clearbrook area should completely recover from the defoliation.

13 Abiotic damage Pine Pests Multiple tops, probably as a result of old winter damage to terminal buds, were recorded Mountain pine beetle on an average of 5% (range 1-11%) of young Dendroctonus ponderosae trees (see pests of young stands section, page 23) at several locations in the southwestern por- Mortality in lodgepole pine due to mountain tion of the region. Damage was recorded at 8 pine beetle attacks increased following seven locations from Spuzzum Creek in the Fraser consecutive years of decline (Figure 5). An esti- Canyon through the upper Fraser Valley, in the mated 15 375 lodgepole pine were killed over Blackwater Creek area north of Pemberton, on 775 ha in 152 infestations in 1992, an increase Texada Island, and north of Gold River on from 7000 trees over 465 ha in 71 infestations in Vancouver Island. 1991 (Table 4). Volume loss increased to approximately 11 275 m3 from 5100 m3 last The multiple tops recorded during 1992 sur- year. Although the area increased by some veys likely resulted from lateral buds competing 65%, the number of trees and volume killed for dominance following winter damage to termi- more than doubled. This is due to several areas nal buds. Several locations in the Fraser being delineated as severely attacked, affecting Canyon, upper Fraser Valley and areas north of the overall tree and volume figures. Mountain Squamish had winter-killed terminal buds pine beetle attacks were only mapped in the recorded during surveys in 1991. Terminal Soo and Fraser TSAs (Figure 6). buds were killed during extremely cold, windy weather recorded in December 1990 and Soo TSA January 1991. In the Soo TSA the area of attack increased Multiple tops can lead to crooks and defects to 735 ha from 385 ha. This almost doubling of by rotation age, or possibly multiple and forked the area attacked is mainly due to an increase stems if no single lateral is able to assume dom- in the number and size of infestations in the inancy. Birkenhead River area near Birkenhead Lake, and and in the Gates River area. There was also an increase in the number of small infestations along the north side of Blackwater Creek. The severity of infestations also increased, par-

Table 4. Recent mountain pine beetle mortality as determined from aerial surveys, Vancouver Forest Region, 1992.

No. of Vol. No. of Area (ha) trees killed killed (m3) infestations

TSA 1992 1991 1992 1991 1992 1991 1992 1991

Soo 735 385 14 775 5800 10 835 4220 98 50 Fraser 40 80 600 1200 440 880 54 21 Mid-coast Sunshine coast

TOTAL 775 465 15 375 7000 11 275 5100 152 71 5000

4000

3000

2000

1000

0 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992

Figure 5. Mountain pine beetle, a 10-year history by area, 1983-1992, Vancouver Forest Region.

ticularly in the flats along the Birkenhead River recorded mortality in this area was in 1990 when near Birkenhead Lake. Elsewhere, the number 13 infestations were recorded covering 5 ha. of small infestations near the mouth of Joffre Creek on the east side of Lillooet Lake Sunshine Coast TSA increased while a few small infestations were also seen on the east side of Little Lillooet Lake. For the fourth consecutive year no beetle attacks were reported in this area. As recently Fraser TSA as 1986, an estimated 2770 ha of infested lodgepole pine were mapped along the For the second consecutive year, no new Homathko River; until the remaining pine reach- infestations were mapped in the Fraser Canyon es maturity, the mountain pine beetle will proba- or associated drainages. In Manning Park, bly remain at endemic levels. approximately 40 ha of recent mortality was mapped, half the area recorded last year. Most A pine sawfly of this mortality was in the eastern portion of the Neodiprion nanulus contortae park. This area is managed under contract that includes conducting ground surveys and traet- A pine sawfly moderately to severely defoli- ing attacked trees with Monosodium Acid ated 15-to 20-year-old lodgepole pine in a 15-ha Methanaearsonate (MSMA). The lack of beetle plantation at 20 km of the Spuzzum Creek road activity in the Fraser Canyon area is largely a northwest of Yale. Small tufts of new foliage result of host depletion and harvesting of previ- were all that remained on most trees after feed- ously infested stands. ing finished in early July. This stand was also defoliated in 1989-90, no defoliation was seen Mid-coast TSA or reported in 1991.

For the second consecutive year there were Although no mortality is expected at no beetle attacks reported in this TSA. The last Spuzzum Creek, continued infestations could VANCOUVER FOREST REGION

PORT ALEERN/

FOREST INSECT AND DISEASE SURVEY

Figure 6. Areas of lodgepole pine recently killed by mountain pine beetle as determined by aerial and ground surveys in 1992. weaken trees making them susceptible to other Spruce weevil insects or secondary organisms. Epidemics Pissodes strobi were reported in Oregon during the 1940s and 50s. The defoliation at this location in 1989 was The spruce weevil continues to cause sig- the first reported outbreak of this pest in the nificant leader mortality of immature sitka Vancouver region spruce throughout the host range in the region. Surveys in 1992 found increased levels of European pine shoot moth attack in most areas. Rhyacionia buoliana On Vancouver Island approximately 10% There was no reported or observed spread current attack, with a higher level of cumulative of this pest in native trees in 1992. The site attack, was found in the Kennedy Lake and where infested Douglas-fir were found in 1989- Carnation Creek areas. Up to 50% current 90 was again re-surveyed, but no damage was attack was found in the Oktwanch River area found. Infested scotch pine and Douglas-fir at north of Gold River. Several mass collections this location were destroyed in 1990 following were made for researchers at the University of confirmation of the shoot moth in native British Columbia and at the Pacific and Northern Douglas-fir. Forestry Centres.

Light to moderately infested Scots and Surveys in the Clowhom Lake and river Austrian pine were found at another Richmond area northeast of Sechelt revealed from 10-75% location where Douglas-fir are growing close to current attack and up to 90% cumulative attack the infested ornamentals. There was no evi- in trees from 3m to 10m tall. These areas had dence of attack in the Douglas-fir this year, how- <5% leader mortality in the early 1980s. ever, this site will be re-surveyed for evidence of Predator larvae of Lonchaea sp., probably attacked native trees in 1993. L. corticis, were common in infested leaders from this area, however, the high weevil populations have caused such severe damage that predation will have little overall impact in these Spruce Pests stands. Parasitism of less than 1% was found in mass collections from this area. The weevil Spruce beetle has effectively eliminated sitka spruce as an Dendroctonus rufipennis acceptable species in young stands on the Sunshine Coast. Spruce beetle populations remained at endemic levels for the sixth consecutive year. Weevil attacks have been a chronic prob- Approximately 2 ha of recent Sitka spruce mortal- lem in the Vancouver region for several ity was recorded at Clayton Falls Creek near decades. Mild winters and warm summers, Bella Coola. A ground survey in the area found along with abundant preferred host material, about 10 red and 4 currently attacked trees. have resulted in generally increasing weevil There was no mortality reported along the attacks. Repeated attacks by the weevil can Nusatum River near Bella Coola in the Mid-coast lead to a reduction of merchantable timber at TSA where 2 ha of mortality were recorded in rotation age due to crook, stem decay, and 1991 and 5 ha were recorded in 1992. other deformities. Current research efforts at the Pacific Forestry Centre are focusing on bio- Eggs and early instar spruce beetle larvae logical control, stand density and species mix, were found in recently windthrown Engelmann tree resistance, and deciduous overstory/over- spruce near Lightning Lakes in Manning Park in topping effect. Surveys will continue in 1993. June. Parks staff were informed of the beetle- infested blowdown and these trees were removed by September. Populations remain low throughout the rest of the region, mainly due to host depletion and logging of susceptible types. Spruce aphid TRUE FIR PESTS Elatobium abietinum

Defoliation of spruce trees by the spruce Western balsam bark beetle aphid increased after declining in 1991. Light to Dryocoetes confusus severe defoliation of spruce was observed and reported throughout coastal and some urban Balsam bark beetle killed some 7300 alpine areas in the Vancouver region. The mild winter fir over 625 ha, down from 12 400 trees over and early, warm spring experienced in south- 1105 ha in 1991. The volume killed declined to western British Columbia is largely responsible 7965 m3 from 13 600 m3 in 1991 (Table 5). for the increased damage by this pest in 1992. This beetle is a chronic pest in many sub- Light to severe defoliation occurred alpine fir stands in the Region. The sporadic throughout eastern Vancouver Island with some and frequently remote occurrence and the noticeable pockets of severely defoliated mature retention of red foliage for several seasons trees occurring in the Campbell River area. makes a consistent and accurate assessment of Mainly moderate defoliation was observed from the damage caused by this pest difficult. Victoria to Jordan River along southwestern Surveys to delineate damage caused by the Vancouver Island. On the lower mainland, bark beetle-fungus complex will continue next widespread light to severe defoliation of native year. and ornamental spruce was observed and reported up the Fraser Valley to Hope. Balsam woolly adelgid Defoliation was reported along mainland inlets Adelges piceae and Islands as far north as Port Hardy. There have been no indication or reports of mortality, Active balsam woolly adelgid (BWA) popu- however, some of the more severely defoliated lations were found, for the first time, on Lasqueti trees may not fully recover. FIDS staff will mon- Island. The presence of the adelgid was con- itor tree recovery in areas experiencing severe firmed in mortality samples supplied by a con- defoliation as well as population fluctuations of tractor. Active populations were also found at this pest in 1993. light levels in true fir seed orchards on the east coast of Vancouver Island. Reports from industry indicate that an area of balsam mortality

Table 5. Estimated balsam mortality by western balsam bark beetle, from aerial surveys, Vancouver Forest Region, 1991

Number of Volume Area (ha) trees killed killed (m3)

TSA 1992 1991 1992 1991 1992 1991

FRASER 475 700 5345 7 900 5820 8 600 SOO 150 375 1970 4 200 2145 4 600 MID-COAST 30 300 400

TOTAL 625 1105 7315 12 400 7965 13 600

18 totaling some 140 ha south east of Port Alberni CEDAR PESTS thought to be caused, in part, by BWA remains unchanged. Surveys to detect the adelgid in young stands in the region were negative. Cedar leaf (keithia) blight Didymascella thujina Following several years of review due to increasing distribution, the old (1976) BWA Infections by this leaf blight fungus remain infestation and regulation zones have been at endemic levels throughout the host range in redrawn. A provincial Order in Council was 1992. This disease is common in stands on the approved on Oct. 22 and a new quarantine zone north shore of Vancouver and the upper Fraser is now in effect (Figure 7). Valley, and was also found at moderate levels in the Kelsey Bay area this year. Surveys found Surveys to detect the spread of this impor- up to 100% of trees affected in dense cedar tant quarantine pest will continue in 1993. stands with reduced infections in spaced stands. Infections are most common on lower Needle blights branches. Isthmiella sp. Phaeocryptopus nudus The diseased branchlets may be mistaken for natural flagging that commonly occurs on A needle blight caused by lsthmiella sp., was western red cedar. In both cases, foliage turns found on two-year-old foliage on 100% of young reddish over the summer. In the case of the amabilis fir in the Eve River valley north of leaf blight, the older branches will become gray Sayward. Surveys found half of all two-year-old and small black fruiting bodies or remaining and older foliage was chlorotic on all trees. All holes can be found on the upper side of infected one-year-old foliage on 100% of the trees had leaves. Heavy infections may cause branch turned red and was beginning to fall off by late mortality on older trees and possibly contribute June. It is not known if the needle blight or a to mortality in understory, sapling trees. weather occurrence caused the foliar discoloration on one-year-old needles, however, the Cedar flagging new foliage was not infected. This genus of needle blight attacks one-year-old and older foliage. The incidence of cedar flagging increased, The area will be resurveyed and samples taken particularly in the mainland portion of thee region in 1993 to determine if the needle blight is in 1992. Although little noticeable flagging was responsible for this foliar discoloration. seen up to mid-summer, widespread moderate to severe flagging was evident by early fall A needle blight caused by P. nudus, was throughout the mainland, particularly in the common on amabilis fir in the Capilano, Pemberton area, the upper Fraser Valley and Seymour, and Coquitlam watersheds. Discol- the Skagit Valley. Discolored foliage was also oration, mainly in the form of chlorotic and, to a evident on eastern Vancouver Island and the lesser degree, red-brown foliage was quite Gulf Islands. noticeable by September during annual assessments of acid rain national early warning system plots in these areas (see special surveys, page 21). The most noticeable infections were in the Hemlock Pest Capilano watershed where most of the amabilis fir was lightly to moderately discolored. All age classes of foliage were affected, with some trees Western blackheaded budworm exhibiting chlorotic foliage throughout the crown. Acleris gloverana Although this blight usually only attacks already stressed foliage, no outstanding stress factors Blackheaded budworm populations on were evident in these areas. FIDS staff will con- northern Vancouver Island, which collapsed in tinue to monitor tree health in these locations 1991 following three years of recorded defolia- next year. tion, remained at endemic levels. For the second consecutive year, no defoliation was Quarantine zone

BELLA COOLA 0 40 80 km

PORT HARDY

PEMBERTON

CAMPBELL RIVER

COURTENAY

Columbia PORT ALBERNI VANCOUVER

NANAIMO

VICTORIA

Figure 7. New balsam woolly adelgid quarantine zone (1992). observed or reported, down from 630 ha in The second part of the study, which was 1990, 7400 ha in 1989, and 4830 ha in 1988. replicated at 11 locations province-wide, consisted of placing 25 freshly cut one-metre-long Although some top-kill was reported, no bolts each of lodgepole pine and western hem- area or percent figures are available, due to lock in a location known to have high woodborer reduced ground and aerial surveys. populations. The Vancouver region location Populations and tree recovery will be monitored was at km 29.5 of the Lillooet River Forest in 1993. Service road, northwest of Pemberton. This mainly Douglas-fir site was burned in a wildfire in 1990. The logs were placed in these locations to see if, under high population pressures, Special Surveys Monochamus spp. would attack western hemlock. Lodgepole pine, a known host of sawyer Pinewood nematode beetles, were placed as control logs. Bursaphelenchus xylophilus At the regional site, 3 of the western hem- Pinewood nematode surveys continued in lock and 7 of the lodgepole pine bolts were the Vancouver region in 1992 with a slightly dif- attacked by Monochamus spp. Additionally, ferent focus. This year a province-wide study both the pine and the hemlock were attacked by was initiated to obtain data for a possible other species of Cerambycidae (roundheaded exemption for western hemlock from a ban on borers), and Buprestidae, (flatheaded borers). non-kiln dried or non-heat pasteurized lumber No pinewood nematode was found in any sam- exports to European Community Countries ples from the regional test site, although the (ECC). A temporary deferral (derogation) of the same three common native nematodes found in ban was to expire in December 1992, but has samples from hemlock logs at dryland sorts been extended to mid-1993 for some European were also isolated from both lodgepole pine and countries. After this date, the ECC will no western hemlock samples at this site. longer accept lumber exports unless they have been kiln-dried or heat-pasteurized. Cedar is Preliminary results from the other test sites currently the only species excempted from this in British Columbia have found pinewood nema- ban. tode in samples from lodgepole pine at 6 locations, and Monochamus spp. in hemlock bolts The study this year was broken down in to from 5 other sites. There is some question two distinct surveys. The first and largest survey about the ability of Monochamus spp. to com- in the Vancouver region, consisted of examining plete its life cycle in western hemlock. Infested hemlock logs, mainly at dryland or mill sort bolts are currently in rearing at the Pacific yards, for the presence or absence of Forestry Centre, the results of the rearings will Monochamus spp. This roundheaded woodbor- be available sometime in 1993. er, or sawyer beetle, is the suspected vector of pinewood nematode. Over 1200 hemlock logs Surveys by FIDS staff during the past were examined at 13 locations in the region. decade have found the pinewood nematode to Although several different types of woodborers be extremely rare in British Columbia. Until this were collected, (Table 6), no Monochamus spp. study, only 6 of over 2000 samples collected were found. Representative samples of insect- from 1980 to 1991 contained the nematode, attacked material as well as control samples representing only individual predisposed trees from these logs were processed and checked at a few widespread locations. for the presence of nematodes. No pinewood nematode were found, although three common Acid rain plots native nematodes (Rhabditae, Tylenchidae, and Dorylaimidae) were isolated from the samples. Annual assessments of tree condition, mor- This survey was conducted province-wide, and tality, acid rain symptoms, and insect and dis- out of over 2300 hemlock logs examined, no ease conditions were made at the 10 existing Monochamus spp. or pinewood nematode were Acid Rain National Early Warning System found. (ARNEWS) study plots in the Vancouver Forest Table 6. Location and types of insects found during log sort surveys, Vancouver Forest Region, 1992.

Number of logs Insects found TSA and location Total Infested C. T.I. G. M.d. L. X.I. S. B. P.t. P.g.

ARROWSMITH TSA Mesachie Lake 100 52 x x X x China Creek 100 11 x Northwest Bay 100 11 x x Chemainus 100 10 x x Jordan River 100 3 x x Honeymoon Bay 100 0 Fanny Bay 48 0

SUNSHINE COAST TSA Port Mellon(Rivtow) 100 18 x Stillwater 100 6 x Port Mellon(CanFor) 100 5 x x x x

FRASER TSA Chilliwack 100 35 x x x x •• Hope 100 24 x x x x

SOO TSA Squamish 100 5 x x

Totals 1248 180 (14%)

1 •C.=Cerambycidae-roundheaded woodborers; T.I.=Trypodendron lineatum-ambrosia beetle; G.=Gnathotrichus spp.-ambrosia beetle; M.d.=Melanophila drummondi- flatheaded woodborer; L.=Lepturinae-roundheaded woodborers; X.=Xylotrechus longitarsus-roundheaded woodborer; S.=Siricidae-horntails; B.=Buprestidae- flatheaded woodborers; P.t.=Pseudohylesinus tsugae-bark beetle; P.g.=Pseudohylesinus grandis-bark beetle

Region. Additionally, a new plot was established foliage in the lower crown of western hemlock, on Saturna Island, one of 12 new plots in the was recorded at two of the plots. These symp- Pacific and Yukon Region in 1992. The Saturna toms were attributed to natural causes. Island site was established next to an Additional foliar discoloration, mainly chlorotic Environment Canada Canadian Air and with some red-brown foliage, on amabilis fir was Precipitation Monitoring Network (CAPMoN) recorded in three plots located in the north station. This will allow easy comparison of tree shore watersheds of Greater Vancouver. While health and weather occurrence data. this chlorotic foliage was observed mainly in the lower crowns of the affected trees, current as There were no acid rain symptoms record- well as older foliage was affected, and in some ed on any vegetation at any of the sites. Some cases the chlorosis extended throughout the foliar discoloration, in the form of chlorotic older crown. A needle blight, Phaeoctyptopus nudus, identified as the causal agent, was most severe Seed orchards in the Capilano watershed. Fifteen seed orchards in the Vancouver Tree mortality was recorded in five plots region were surveyed at least once in 1992 for where a total of 10 trees died (Table 7). The the detection of insects, diseases and abiotic largest single cause of mortality was shading damage. Transfer of technical information as out and suppression which killed 8 trees. well as discussions on management options are Mainly secondary bark beetles, which were also a part of these surveys. Numerous insects, found in two of the dead trees, were probably diseases, and other problems were recorded, attracted as the trees became stressed. Two most of which are not serious. Some of the trees died as a result of storm damage. The most common pests are listed below. A com- 1992 mortality represents only 2% of the total plete detailed list of all pests found during the number of trees in all the ARNEWS plots in the surveys is compiled as an appendix to this Vancouver region. To date 98 trees, or 15% of report and is available on request. the total, have died with all mortality attributable to natural causes. When any serious problems are encountered, seed orchard staff are informed and, if These plots, part of a national system to necessary, further surveys are conducted. gather baseline data on acid rain in Canadas These surveys are intended to enhance the forests, will continue to be monitored in 1993. efforts of Ministry of Forests and industry staff and specialists as well as provide a survey from Pests of young stands a different perspective. The low incidence of significant insect or disease problems reflects A total of 30 young stands were surveyed the efforts and attention displayed by seed for pest incidence in the Vancouver region in orchard staff. 1992. These stands ranged in age from 2-to 50-years old, but most (90%) were in the 15-to Douglas-fir 25-year-old range and had recently been spaced and/or fertilized. A total of 3117 trees The Cooley spruce gall adelgid, Adelges representing 9 species were examined, of which cooleyi, was the most common pest on 2666 or 86% were pest free. The results of the Douglas-fir, lightly infesting from 10 to 100% of survey are summarized in Table 8. Only six the trees at nine orchards. The Douglas-fir nee- tree species are tallied in the table. The other 3 dle midge, Contarinia pseudotsugae, lightly species, lodgepole pine, western white pine, infested from 1 to 50% of trees at seven and mountain hemlock had less than 10 trees orchards. The fir coneworm, Dioryctria abieti- per species in all 30 stands. No pests were vorella, lightly infested cones and boles at four found on the lodgepole pine, branch infections and two orchards respectively. Low levels of of white pine blister rust were found on two the western spruce budworm, Choristoneura white pine in three stands, and one mountain occidentalis, were recorded at three orchards. hemlock had poor form in one stand. Western hemlock Needle diseases were the most common pest encountered, affecting 237 trees overall, or The hemlock woolly adelgid, Adelges tsug- 8% of trees surveyed. Abiotic damage, consist- ae, lightly to moderately infested up to 80% of ing mainly of multiple tops and poor form, was the trees at three orchards. the next most common pest affecting 92 trees or 3% of the total. The most damaging pests were True fir competition, blowdown, and Armillaria root disease, which affected 11, 9, and 6 trees respec- Mainly old, moderate to severe, gouting tively. These damaging pests represent only 1% caused by the balsam woolly adelgid, Adelges of the total trees surveyed. piceae, was noted on up to 90% of the trees at two orchards.

23 Table 7. Current and cumulative tree mortality in ARNEWS plots, Vancouver Region, 1992.

Mortality Plot number Total trees and location sps1 at plot est. 1992 1984-1991 total cause in 1992

901-Shawnigan Lk. dF 120 24 24 W 8 1 3 4 shaded/suppressed wwP 2 902-UBC forest wH 32 14 14 wrC 15 6 6 - B 3 1 1 903-Saltspring dF 100 4 17 21 shaded/suppressed wrC 2 904-John Hart Lk. dF 30 1 1 IP 1 909-Jones Lake wH 57 - 8 8 dF 2 wrC 1 910-Capilano R. aF 57 2 6 8 shaded/suppressed and bark beetle, Pseudohylesinus grandis wH 17 wrC 1 911-Seymour R. dF 36 5 5 wH 2 912-Seymour R. dF 24 2 2 4 shaded/suppressed and storm damage wH 23 - aF 5 - 913-Or Creek wH 46 wrC 20 1 1 2 storm damage aF 3 dF 2 914-Coquitlam Lk. aF 36 - wH 29

Total 674 10 88 98

Percent mortality 2 13 15

1dF-Douglas-fir; W-willow; wwP-western white pine; wH-western hemlock; wrC-western red cedar; B-birch; IP-lodgepole pine; aF-amabilis fir

24 Table 8. Results of pests of young stands surveys, by host and pest in descending order of importance, Vancouver Forest Region, 1992.

Severity Affected no. of % of trees affected2 Host/pest index trees stands average range

Douglas-fir -1296 trees in 21 stands, 1118 trees pest free Armillaria root disease 6 6 4 2 1-3 Mortality (cause unknown) 6 1 1 1 1 Blowdown 5 3 2 20 11-29 Competition 5 1 1 1 1 Abiotic 3-5 41 13 5 1-13 (multiple tops, poor form) Browse 3-4 3 3 2 1-4 Mechanical 2-4 5 3 5 1-13 Spruce budworm 3 92 1 100 100 Needle disease (unknown) 2 33 2 22 10-33 Adelgid 2 3 1 100 100

Western hemlock - 1062 trees in 30 stands, 1028 pest free Unknown 6 4 2 5 4-5 Blowdown 5 2 2 3 2-4 Abiotic (poor form) 5 5 4 4 1-6 Browse 4 23 1 29 29

Western red cedar - 303 trees in 17 stands, 238 pest free Competition 6 10 1 12 12 Blowdown 5 4 2 7 5-8 Abiotic (poor form) 3-5 12 3 8 1-12 Keithia blight 2 21 3 71 13-100 Cedar flagging 2 18 3 21 3-33

Amabilis fir - 286 trees in 20 stands, 126 pest free Abiotic (poor form) 3-5 7 4 25 9-100 Mechanical 3 1 1 100 100 Spruce budworm 3 1 1 100 100 Fir-fireweed needle rust 2-3 165 8 69 37-100

Sitka spruce - 100 trees in 7 stands, 99 pest free Abiotic (multiple top) 11

Englemann spruce - 46 trees in 2 stands, 37 pest free Unknown 6 1 1 2 2 Abiotic (poor form) 4 6 2 56 11-100 Competition 3 2 1 4 4 Adelgid 2 1 1 100 100

Severity index: 1. pest free 2. minor damage, minimal impact 3. significant loss of current growth potential 4. net volume loss or loss of significant long-term growth potential 5. life threatening or severely deforming 6. recently dead or dying 2Percent of trees affected includes only trees from stands in which the pest occurred. Sitka spruce pheromone traps, prompted an eradication attempt. Aerial and ground spray applications The ragged spruce gall adelgid, Pineus were carried out over some 18 800+ hectares in similis, caused light galling on up to 20% of Greater Vancouver using Bacillus thuringiensis trees at three orchards. Galls formed by the var. kurstaki (Btk., Foray 48b) during the late Cooley spruce gall adelgid, Adelges cooleyi, spring and early summer of 1991. The spray lightly infested 10% of the trees at one orchard. program appears to have been successful as no Asian adults were reported caught in any traps Seed orchard surveys will continue in 1993 in 1992, and only one European adult was and significant problems will be reported as they caught in traps placed within the 1991 spray are noted. zone.

This is the sixteenth year of a cooperative program with Agriculture Canada (plant health Deciduous Tree Pests section), the British Columbia Ministry of Forests and Forestry Canada, FIDS. Over 16 Gypsy moth 000 sticky traps were placed throughout the Lymantria dispar province in 1992 as part of this program. Traps will be placed and monitored by all participating Three adult male gypsy moths were caught agencies in 1993. in 105 pheromone-baited sticky traps placed at 84 locations, mainly in provincial parks and pri- Winter moth vate campgrounds, throughout the Vancouver Operophtera brumata region by FIDS staff (this includes 5 placed in the Bella Coola area). One moth was caught at Winter moth populations increased on the each of Kawkawa Lake Provincial Park just west lower mainland after declining in 1991. This is of Hope, at Hicks Lake Campground in the fourth consecutive year of winter moth defo- Sasquatch Provincial Park near Harrison Hot liation on the lower mainland. On Vancouver Springs and at Porteau Cove Provincial Park Island, scattered light defoliation occurred in his- between Horseshoe Bay and Squamish. All torically active areas in Greater Victoria with a three were of the European biotype (race). few severe pockets. Additionally, one more European moth was caught in a FIDS-placed trap at Okanagan In lower mainland areas, scattered light to Lake. severe defoliation of individual and groups of deciduous hedgerow, ornamental and shade About 163 males were caught in traps trees was observed and reported in Delta, placed by Agriculture Canada this year, com- Ladner, and Surrey as well as in the City of pared to about 70 in 1991. Additionally, 3 Vancouver around Point Grey and Marine Drive females and some egg masses were found by south of UBC. Patchy moderate to severe defo- Agriculture Canada in Richmond. This is the liation was also reported in a few other areas in highest number of moths caught since 1987 south Vancouver. On southern Vancouver when 221 adults were trapped at Kelowna. Island, mainly light defoliation was observed in Adults were trapped at various locations from previously active areas in Greater Victoria. the Comox area to Victoria on Vancouver Additionally, localized pockets of severe defolia- Island, on Saltspring and Mayne islands, and on tion occurred in the Landsdowne area of the lower mainland from Vancouver to Hope. Victoria and at Cattle Point in Oak Bay.

In 1991, 12 Asian gypsy moths were caught The City of Vancouver is considering con- in traps placed by Agriculture Canada. These trol options in light of increasing populations. catches followed the introduction of the Asian Besides an increased tree banding program in biotype into the Vancouver area via cargo ves- areas of high populations, the City has contact- sels from eastern Russia, where an infestation ed personnel in the biological control group at was in progress. The finding of egg masses on the Pacific Forestry Centre and is investigating these ships, followed by adults caught in the possibility of biocontrol similar to that imple- mented in Greater Victoria in 1979. The para- Most trees refoliated by mid-summer and sitic fly and wasp release in Greater Victoria has although no mortality is expected, growth loss been considered a success in reducing winter may occur in trees experiencing moderate to moth populations and limiting defoliation. severe defoliation over consecutive years. Trees suffering repeated defoliation may also FIDS staff will continue to monitor and become more susceptible to root rots and other report on winter moth populations, particularly in diseases. There is some concern about hybrid lower mainland areas in 1993. poplar plantations in the area. Repeated moderate to severe defoliation of these fast growing, A cottonwood sawfly high value, younger trees may result in higher Nematus currani volume loss than in the mature native cottonwood. FIDS staff will continue to monitor this Defoliation of mainly native black cotton- pest in 1993. wood by this sawfly continued for the second consecutive year. The area defoliated increased to 685 ha of light to severe defoliation Bigleaf maple scorch and leaf spots in 28 patches from 50 ha of moderate to severe Xylella fastidiosa in 1991. There were 140 ha of light, 430 ha of Rhytisma punctatum moderate and 115 ha of severe defoliation Cris tulariella depradens recorded during aerial surveys in early May. This is the first known outbreak of this pest in The incidence and intensity of bigleaf maple British Columbia. Records prior to last years scorch increased, particularly in lower mainland defoliation were from widely scattered single or and Sunshine Coast areas in 1992. Damage on small groups of defoliated trees. Vancouver Island and Gulf Islands areas was similar to 1991. Leafspots were only recorded Defoliation was confined mainly to islands in lower mainland areas and remained at levels in the Fraser River from the Herrling Island similar to 1991. group east of Agassiz to the base of Sumas Mountain west of Chilliwack. Some defoliation Scorched leaf margins were visible in was also seen on the western end of Matsqui some lower mainland and Sunshine Coast Island near Mission. Most of this defoliation areas by early July and became widespread by was in TFL 43, islands in the Fraser River late summer. On Vancouver Island, scorched managed by Scott Paper. Although the native foliage was again common in the Goldstream black cottonwood were the main host, trace to and Malahat north areas by mid-summer and light, with some moderate feeding was noted was seen at levels similar to, and in the same on hybrid poplars in plantations on several areas as were infected, in 1991. Leaf spotting islands in the Agassiz-Chilliwack area and at caused by the tar spot fungus, R. punctatum Scott Papers Harrison Mills and Kilby and a leaf spot fungus, C. depradens, were Nurseries. common on the north side of the upper Fraser Valley and upper Harrison Lake areas by mid- The defoliation this year occurred very early, summer. Two other, mainly secondary fungi, the larvae had completed their feeding and had associated with leaf margin browning, begun pupating by the first week in May. In Diplodina acerina and Discula sp. were found 1991, the larvae completed their feeding by the on collections from lower mainland locations end of June. The extremely mild winter and early (see other minor and noteworthy pests, page spring recorded on the lower mainland was prob- 31). The combination of leaf margin scorching ably responsible for the very early feeding that and leaf spots gave bigleaf maple a very fall- occurred this year. Very little is known about the like appearance in some areas by mid-sum- life cycle of this sawfly, however, like other mer, particularly at upper Fraser Valley loca- sawflies in B.C. the larvae pupate in the duff at tions. the end of their larval stage. It is believed that the adults emerge to lay their eggs very early in Tests using an Enzyme-Linked Immuno- the year as larval development and feeding sorbent Assay (ELISA) kit indicate that some, begins as soon as foliage flushes in early spring. but not all, of the scorched maple leaves from various locations tested positive for X. fastid- severely defoliated at this park over the past few iosa, a fastidious xylem inhabiting bacterium. years. The affect of this defoliation coupled with Collections from Goldstream and Greater a high incidence of dogwood leaf blight may be Victoria on the island and Gates Lake and partially responsible for some of the die-back Powell River on the mainland were positive. and mortality seen here this year (see Dogwood This is the first record of this bacterium on leaf blight section, page 28). bigleaf maple. As well, some samples collected from Stanley Park in 1991 were re-tested and Outbreaks by this defoliator usually col- confirmed positive. It should be noted that lapse after a few years. The last recorded out- although the bacterium has been detected and break in the Vancouver region was at Railroad proven to cause similar symptoms on other Creek in 1972. hosts, it has not been consistently correlated with scorch symptoms on bigleaf maple. Dogwood leaf blight Discula (Gloeosporium) destructiva FIDS personnel will continue to make collections of and observe and report on bigleaf Discoloration and premature defoliation of maple discoloration next year. western flowering dogwood by this leaf blight fungus continued at moderate to high levels Western winter moth throughout the host range in 1992. This blight, Erranis tiliaria vancouverensis which has been a chronic and common problem in the region for over a decade, causes branch Western winter moth populations collapsed dieback and some mortality, especially on heav- at Alexandra Bridge, Emory Creek and Cultus ily infected understory trees. Lake provincial parks, the last remaining areas infested by the western winter moth in this most Infections were widespread from south of current outbreak. No defoliation was recorded Boston Bar to Vancouver, the Squamish and or reported region-wide. Sunshine Coast areas and throughout most of the southern half of Vancouver Island. Up to Widespread defoliation was recorded from 100% infection of foliage was common, even on 1988-90 at several areas in the upper Fraser some of the more open growing trees. Valley, including Sasquatch Provincial Park, Alexandra Bridge Provincial Park, Cultus Lake At Alexandra Bridge Provincial Park where Provincial Park, Skagit Valley, and the Fraser severe infections have persisted for several Canyon from Hope to Boston Bar. Populations years, many understory trees are dead or have in most of these areas collapsed in 1991 with severe crown die-back. This may be partly due the exception of Alexandra Bridge, Cultus Lake, to the western winter moth, which moderately to and Emory Creek provincial parks. Although severely defoliated understory trees from 1988- populations were noted at Cultus Lake in early 91. 1991, only trace defoliation occurred as the larvae succumbed to a nuclear polyhedrosis virus Some infected foliage hangs on the trees (NPV) found in larval collections there in 1990 rather than dropping off in the fall, this plus and 1991. That left Alexandra Bridge Provincial infections in blighted twigs means the inoculum Park with moderate to severe defoliation and is present on the trees in the spring. Emory Creek Provincial Park with trace defolia- Additionally, infected foliage that has fallen off tion as the last remaining areas defoliated by affected trees is also a source of infection. Rain the western winter moth in 1991. Populations in splash then causes spore dispersal to adjacent both of these parks collapsed this year and no new foliage. Homeowners can try to protect defoliation was recorded. ornamental trees by removing and destroying infected foliage and small branches as well as Although no mortality was recorded as a raking and removing all foliage under the trees result of this outbreak, the defoliation may have before leaf flush in the spring. contributed to die-back in understory dogwood trees at Alexandra Bridge Provincial Park this year. Understory trees were moderately to Birch Leafminers trees were observed in all of these areas. Fenusa pusilla There were no populations seen or reported in and the Sunshine Coast area following high popula- Profenusa thomsoni tions last year.

Populations of both the birch leafminer, Webworm tents were common on alder, F. pusilla, and the ambermarked birch leafminer, poplar, willow and various fruit, ornamental and P. thomsoni increased this year. Mainly moderate shade trees. Tents were noted as early as the to severe discoloration occurred in natural stands first week in July, a few weeks earlier than of white birch throughout the lower mainland, par- usual. The warm spring and early summer ticularly the upper Fraser Valley and lower Fraser experienced throughout the region is probably Canyon areas. responsible for the early development of this pest. The birch leafminer caused moderate to severe damage throughout the lower Fraser In severe infestations larvae can defoliate Canyon area, particularly around Emory Creek entire trees. However, usually only individual Provincial Park. Damage was visible throughout branches are defoliated. Homeowners wishing the area by early June. The ambermarked birch to protect fruit and shade trees can clip and leafminer was collected in the Floods area, west burn infested branches. Insecticides registered of Hope in early July. Both species cause simi- for use against leaf-chewing insects should be lar damage. The larvae mine the foliage, caus- effective if sprayed on the feeding areas when ing wrinkled and blotched leaves. This foliage the young caterpillars are spinning webs, usual- turns prematurely brown giving the trees a ly in early summer. scorched appearance. Jumping gall wasp Repeated severe infestations, which in Neu roterus saltatorius ornamental or shade trees may cause some die-back, can be controlled with proper use of a Severe scorching and some defoliation of systemic insecticide. Damage in natural stands Garry oak foliage caused by the jumping gall is mainly aesthetic and control is usually not wasp spread and increased for the seventh con- warranted. secutive year in the Greater Victoria area. The infestation spread as predicted and caused Fall Webworm severe scorching in Victoria and Oak Bay as Hyphantria cunea well as causing noticeable scorching in Greater Victoria areas already infested with the gall Populations of this common defoliator of wasp. Damage was also reported for the first hardwood trees continued at high levels for the time in the Maple Bay area near Duncan and at fourth consecutive year in the Lower Mainland Nanaimo. No damage has been reported, to and on Vancouver Island. Moderate to severely date, on the Gulf Islands. infested trees were common in the upper Fraser Valley from Mission to Hope, with a dozen or Bearings at PFC indicate a continuing rela- more tents visible on trees by late July. tively low level of parasitism by five species of Occasional tents were seen on trees as far as chalcid parasitoids, however, in a few sites the Yale in the Fraser Canyon, and along both sides level of parasitism was somewhat higher (30- of Harrison Lake as far north as the Lillooet 40%). Damage is expected to continue in previ- River. Lightly infested trees were also noted in ously infested areas with further expansion of the Delta and Ladner areas, in the Fraser Valley the infestation north to Deep Cove. Damage is through Langley and Surrey, and reported in the expected to remain light at Duncan and Maple Ridge area. A few infested trees were Nanaimo. Jumping gall wasp infested foliage also noted in the Squamish area. High popula- can be identified by examining the underside of tions were noted on southeastern Vancouver the leaves which have large numbers of small Island from Victoria to Comox. Light to severe (1.0 to 1.5mm) round galls attached to them. defoliation of branches and occasional small An Oak leaf phylloxeran New Records of Occurence and Phylloxera sp. near glabra Distribution Premature browning and defoliation of Garry oak, caused by an introduced oak leaf A total of 10 disease collections were new phylloxeran, affected about 10% of the oaks in records in 1992. There were 6 new records and the greater Victoria area, similar to 1991. This 4 new host records, most of which were sec- year, damage was reported for the first time as ondary leaf spots and saphrophytes. Seven of far north on the Island as Comox. In 1991 the the records were on deciduous hosts and three phylloxeran spread to Nanaimo and the Gulf were on conifers. Islands. The phylloxeran tends to re-attack previously infested trees, many of these repeatedly attacked trees in the Capital region are currently in very poor health.

The phylloxeran has now spread virtually throughout the range of Garry oak in British Columbia, the only exception being some of the Gulf Islands. The damage caused by this insect can be identified by examining the lower surface of the affected foliage, the oak leaf phylloxeran-injured leaves are covered with numerous minute orange insects resembling aphids. Damage is expected to continue on chronically infested trees. FIDS personnel will continue to monitor and report on this pest.

30 OTHER NOTEWORTHY AND MINOR PESTS

Table 9. Other noteworthy and minor pests, Vancouver Forest Region, 1992.

Host and pest Location Remarks

CONIFERS

Amabilis fir A bark beetle, Bella Coola, Found in recently killed trees Pseudohylesinus grandis Capilano River A needle blight, North Up to 90% of trees with up to Phaeocryptopus nudus Vancouver 50% of foliage infected A shoot boring sawfly, Higher elevation Very light damage in some Pleroneura sp. mainland stands locations Dwarf mistletoe, Upper Lillooet Aerial shoots and branch Arceuthobium tsugense River swelling on some trees. A rare occurrence Douglas-fir Green-striped forest looper, Region-wide Larvae common in collections Melanolophia imitata Silver spotted tigermoth, Region-wide Scattered light defoliation Lophocampa argentata

Pines A needle cast, Hornby Island, Lightly infecting most trees in Davisomycella ampla Pemberton area these locations A needle cast, Nanaimo, Comox, Locally severe infestations at Lophodermella concolor Port McNeil Xmas tree farms and individual trees A needle blight, Texada Island, Most trees lightly infected Lophodermium pinastri Paldi White pine blister rust, Manning park, Branch and stem infections Cronartium ribicola high elevations common on whitebark pine Pine shoot beetle, Lower mainland Surveys in Scots pine for this Tomicus piniperda Xmas tree farms European pest, recently found in the U.S. mid-west, were negative Ornamental cedar, cypress, juniper A stem/root pathogen, Agassiz Associated with ornamental hedge Gibberella baccata die-back. A new record in B.C. Cypress tip moth, Vancouver Widespread light damage on Argyresthia sp. Island ornamentals

Western hemlock Dwarf mistletoe, Region-wide Endemic, widespread Arceuthobium tsugense Western hemlock looper, Mainland areas Larvae in beating samples and Lambdina f. lugubrosa adults in pheromone traps

Western larch Larch sawfly, Region-wide Scattered moderate-severe Pristiphora erichsonii defoliation of ornamentals Western yew Yew big bud mite, Island and Common in coastal areas, not Cecidophyopsis psilaspis mainland found at any interior sites A shoot blight, Birkenhead Common, causing minor branch Dothiora taxicola River area tip die-back

Yellow cedar Cypress twig mite, Vancouver On ornamentals and in Triseticus chamaecypari island seed orchards

DECIDUOUS

Alder Alder woolly sawfly, Southwestern Common, causing scattered Eriocampa ovata B.C. light to moderate defoliation Western tent caterpillar, Clayton Falls, Scattered light defoliation Malacosoma c. pluviale Soolumpt Creeks

Apple Apple ermine moth, South Vancouver Light to moderate defoliation Yponomeuta malinella Island, Agassiz at scattered locations

Bigleaf maple A leaf blight, Powell River, Contributing to leaf margin Diplodina acerina Yale browning. A new record in B.C. A leaf blight, Harrison Bay Contributing to leaf margin Discula sp. area browning A powdery mildew, Davis Lake, Causing foliar discoloration Uncinula bicornis Hope.

Birch A leaf spot, Maple ridge Light to moderate leaf spot on Taphrina sp. most birch, UBC research forest

Poplars A bud midge, Southwestern Common for sixth consecutive Dasineura sp. B.C. year, mainly light bud kill on native cottonwoods A leaf beetle, Upper Fraser Common on native and hybrid Phratora sp. Valley poplars A leaf beetle, Upper Fraser Common on native and hybrid Syneta albida Valley poplars A leaf mining beetle, Southwestern Common on native and hybrid Zeugophora sp. B.C. poplars Septoria leaf spot, Harrison Mills Causing light-moderate leaf Mycosphaerella populicola spot, common on hybrid poplar

Willow Pacific willow leaf beetle, Bella Coola, All trees up to 4m tall 50-100% Pyrrhalta decora carbo Stuie defoliated Poplar and willow borer, Bella Coola common in willow throughout this Cryptorhynchus lapathi valley area

32 QUEEN CHARLOTTE ISLANDS

Summary near Alliford Bay. At the outbreak of the infestation in 1985, the nearest recorded activity was Western blackheaded budworm popula- five kilometers away at Haans Creek, where tions remained at low levels, no larvae were trees were moderately defoliated. In 1986 defo- found. Small populations of hemlock sawfly liation was light, and in 1987, probably light to remained at several locations on the Queen moderate. The nearest defoliation recorded in Charlotte Islands but no defoliation was 1988 was on the north end of Maude Island. recorded. Hemlock dwarf mistletoe remains The stand was spaced in 1989. a chronic problem throughout the islands, affecting old growth and young spaced stands. Assessment of the stand in 1992 did not indicate any residual crown damage caused by Spruce aphid lightly to severely defoliated the outbreak. Damage was confined to minor Sitka spruce over an estimated 3140 ha mostly sapsucker activity (7% of hemlock), occasional along the east coast. Galls on spruce caused minor crooks, fork, or sweep (6% of trees) and by Cooley-spruce gall adelgid were noted in in one area hemlock dwarf mistletoe (2%). An Sandspit. Douglas-fir, the alternate host, were assessment of growth rates (based on one core lightly to severely infested at two of four loca- sample from each of 10 plots) during the out- tions surveyed. Spruce needle blight caused break period indicated a trend but was not con- minor discoloration of 1991 needles in several clusive. Radial increment averaged 3.56 mm areas. Although large-spored spruce- during the outbreak period, 19% less then the Labrador tea rust infections declined, light to average increment of 4.39 mm for the period of severe discoloration was observed at several 1977-84. After a recovery period and spacing, areas on Graham Island. the 1990-91 increment averaged 4.79 mm, 38% greater than the increment found during the In surveys for Pests of Young Stands, infestation period and already 9% greater than only deer-browse and hemlock dwarf mistletoe that found during the pre-spacing/pre-infestation were found to seriously threaten spaced stands. period.

Several pests causing minor damage or Information on this stand is sketchy. It is noted at endemic levels are included in table 10 possible some feeding may have occurred in at the end of this report. 1985 and 1988 which was not recorded during aerial or ground surveys. The recorded defoliation of 1986 and 1987 may not have been uni- form as aerial survey maps show the defoliation Hemlock Pests boundaries running adjacent to the surveyed area. While results of the core sample analysis Western blackheaded budworm were not decisive, increment during the entire period was lowest in each of the four infestation Acleris gloverana years and excepting 1980, increment was great- est in the two years following spacing. More Western blackheaded budworm populations data from similarly affected areas would aid in remained at endemic levels in 1992. No larvae development of conclusions. were collected in 14 standard FIDS larval samples throughout accessible areas of Graham The trend suggests that on good sites, near and Moresby islands. This continues the low 100% defoliation causes dramatic reduction in level of budworm population found since the col- radial growth while light defoliation may impact lapse in 1987. tree growth. In both cases, recovery appears to be rapid and complete. Effects of the western blackheaded budworm/hemlock sawfly infestation of 1985 to 1988 on young trees were assessed in a stand Hemlock sawfly SPRUCE PESTS Neodiprion tsugae

No defoliation was recorded in the district. Spruce aphid At Marie Lake, where trace defoliation in young Elatobium abietinum hemlock was recorded in 1991, only 21 larvae were collected in a standard three-tree beating The spruce aphid defoliated an estimated sample. Only three larvae were found at 3140 ha of Sitka spruce in 13 areas, based on Hangover Creek and none at Gregory Creek. In ground assessments alone. This is the second 23 other standard samples a maximum of 12 year of attack and a major increase from the larvae were found and no defoliation was noted. mostly sporadic light attack noted in 1991. Monitoring of this pest will continue in 1993. Affected areas on Graham Island totalled Hemlock dwarf mistletoe about 2600 ha mostly along the coast from west Arceuthobium tsugense of Queen Charlotte City to Tlell, from Griffith Point to near Masset, and from east of Masset, Hemlock dwarf mistletoe, A. tsugense, to the mouth of the Sangan River. On Moresby remains a chronic and common parasite of Island, 540 ha in 7 areas were aphid-damaged, western hemlock throughout the Queen including Gray Bay, Copper Bay, the Sandspit Charlotte Islands. Near Alliford Bay, a 20-year- area and the east side of Maude Island. old stand that had been spaced in 1989, had 2% of crop trees infected by mistletoe (based on Defoliation and discoloration was mostly a 10 plot, 105 tree assessment). In a similar light to moderate in older foliage. However, young, spaced stand at Florence Creek, an some areas of severe attack including feeding overstory infected tree was double girdled but on current flush were noted in the Skidegate remained alive. Visibly infected young trees Mission area, near Tlell and south of Lawnhill. had been removed during spacing, however, Other areas of mostly trace to light spot damage mistletoe is expected to become evident in the in roadside regeneration and young plantations next few years due to the presence of the sur- included Tow Hill, Misty Meadows Park, the viving seed source. At Tow Hill, mistletoe Rennet Sound Recreation area, Bonanza brooms were common to numerous in all age Creek, Heather Lake and Ski Jump Creek. classes along the entire length of the trail. At a Heather Lake study plot, in a young At Gregory Creek, in an old growth stand stand where Sitka spruce represented an esti- resurveyed to establish long term "after-harvest" mated 25% of the crop trees, all spruce trees monitoring and demonstration plots, mistletoe were infested, similar to 1991. From 10-80% of was common in several areas. Overall, 38% of older foliage was attacked in 90% of the trees plot trees were infected. Of these, 53% were with over 80% of foliage infested in the remain- lightly infected, 23% were moderately infected ing 10% of trees. Overall, 57% of foliage was and 23% were severely infected. This is a con- affected as compared to 41% in 1991. Effects siderable reduction from the 1991 findings. of the attacks on lateral shoot lengths were However, two of the plots established this year examined. In 1991, severely defoliated trees were located in the upper reaches of the stand showed a decrease in shoot length of 11%, where no mistletoe was seen. This significantly compared to lightly defoliated trees. A compari- lowered the overall average. son, in 1992, of severe to moderately infested trees showed a decrease in lateral shoot length Regeneration in and adjacent to plots of 28%. Overall average shoot length in 1992 appeared uninfected. Most were 0.5-3 m in was 24% shorter than in 1991. These results height and only entering the susceptible period. suggest a cumulative growth loss effect follow- Single tree and patch harvesting without regard ing successive years of attack. to the diseased overstory will perpetuate the disease within the stand. No branch dieback or mortality was noted in young trees. Mortality of mature Sitka spruce has been recorded in the past in association infects current foliage. Discoloration is not visi- with repeated severe spruce aphid attack. ble until the following year. Attack levels in 1993 will depend in part on overwintering conditions. Monitoring will contin- Large-spored spruce-Labrador tea rust ue. Chrysomyxa ledicola

Cooley spruce gall adelgid This rust infected current foliage of Sitka Adelges cooleyi spruce at three locations. The disease was noted in a 0.3 ha patch in the Boulton Lake area In Sandspit, six of eight young Sitka spruce north of Port Clements, along the road between were infested with current galls of the Cooley Port Clements and TleII in scattered patches, spruce gall adelgid. In addition, 10 of 12 and in one spot near Juskatla. Affected trees Douglas-fir, the alternate host, were lightly to were lightly to severely discolored by mid-July. moderately infested with woolly adelgids. Near Queen Charlotte City, three young Douglas-fir In moist seasons this rust may become epi- trees were severely infested. Control efforts at demic, and while only current foliage is infected, this site, earlier in the year, using a systemic 90% loss of needles has been reported. insecticide, were unsuccessful. No galls were Epidemics of this severity can affect growth in found during a survey of roadside and shorefront the following years. spruce within 0.5 km of the infested Douglas-fir. The disease can be controlled by not plant- Douglas-fir and adjacent Sitka spruce were ing spruce near swamps containing the alter- also assessed at two sites at Port Clements. nate host, Labrador-tea, or by removal of the No adelgids or galls were found. Although scat- alternate host from the vicinity. tered individual Douglas-fir trees have also been located in the forests of the Queen Charlotte Islands, no adelgids have been reported. Pests of Young Stands Galls on young spruce cause branch defor- mation and can significantly impact growth A total of four young stands were surveyed potential. Beyond the few infested trees in on the Queen Charlotte Islands as part of an Sandspit, surveys indicate no establishment of ongoing program to assess pest problems in A. cooleyi in Sitka spruce forests or plantations. young stands throughout the province. In addi- Complete removal of Douglas-fir is recommend- tion to insect and disease concerns, environ- ed as the best means of ensuring that this does mental damage, mammal damage and any not occur. other conditions affecting the health and growth of young stands were surveyed. Stands were Spruce needle blight selected primarily on the basis of having been Lirula macrospora treated under the Forest Resource Development Agreement (FRDA) or the South Infections by spruce needle blight declined Moresby Forest Replacement Account in 1992. Approximately 50% of roadside Sitka (SMFRA). spruce were lightly to moderately discolored along a logging road adjacent to the Yakoun An average of 78% of trees were pest free River. Spot discoloration was also noted on and only 1 % were found to harbor serious prob- roadside trees in the Rennel Sound Recreation lems. At Florence Creek, 16% of western red are and in the Copper Creek area. cedar were moderately to severely deer- browsed. Cedar represented only 18% of the Widespread light to severe discoloration, trees surveyed at this site and most were recorded in 1988 and 1990, was also expected younger regeneration not intended as crop trees. this year. Conditions leading to the spread of this disease must not have occurred during the Hemlock dwarf mistletoe, Arceuthobium period of spore dispersal in the spring of 1991. tsugense, was found on 2% of crop trees at an This disease, which has a two-year life cycle, Alliford Bay plantation and on one surviving seed tree, mechanically girdled but still alive, at Other minor conditions on hemlock included Florence Creek. In both cases, the current sapsucker damage, minor forks and crooks, and infection rate was light and affected only a small a trace of hemlock-blueberry rust. Minor flag- segment of the areas surveyed. The mistletoe ging, scarring, and leafblight on western red will be a continuing problem in these planta- cedar and small populations of spruce aphid tions. and minor budmoth damage on Sitka spruce were also noted. MINOR PESTS

Table 10. Pests at endemic levels or causing minor damage, Queen Charlotte Islands, 1992

Host and pest Location Remarks

CONIFERS

Pines

A needle cast fungus, Pure Lake Light to mod. discoloration to Lophodermium seditiosum 10-20% of young pine over 10 ha

Atropellis canker, Graham Island Causing minor branch cankering Atropellis pinicola to +1- 5% of young bog pine

Pine leaf chermid, Jungle Creek Small populations in plantation Pineus pinifoliae trial of western white pine

Red band needle disease, Rennel Sound Mod. to sev. discoloration to Scirrhia pini 80% of 2-5 m bog pine

White pine blister rust, Jungle Creek Infection found in plantation Cronartium ribicola trial of western white pine

Sit ka spruce

An adelgid, Heather Lake Small populations of woolly Pineus. sp. adelgids and galls on 15% of young spruce

Giant conifer aphids, Lawnhill Eggs numerous on new flush Cinara sp. at several locations

Greenheaded spruce sawfly, Queen Charlotte Occasional larvae scattered Pikonema dimmocki Islands throughout, no damage

Red ring rot, Tow Hill Ecological Approximately 5% of roadside Pheffinus pini Reserve, Hangover mature trees with conks, Creek midcrown conks in 1 of 7 plot trees

Spruce budmoth, Queen Charlotte Scattered trace to very light Zeiraphera sp. Islands bud damage throughout

White mottled rot, Gregory Creek Common in dead trees and stumps Ganoderma applanatum

Western hemlock

Hemlock-blueberry rust, Survey Creek Negligible infection Pucciniastrum vaccinii

Western yew

Yew big bud mite, Heather and Marie Common throughout host range Cecidophyopsis psilaspis lakes, Yakoun River

37 Yellow cedar Yellow cypress rust, Phantom Creek Common on branches but not Gymnosporangium nootkatense abundant

DECIDUOUS

Black cottonwood A leaf blight, Skidegate Common, causing minor leaf Taphrina populina blisters Septoria leaf spot, Skidegate Common, causing minor leaf Mycosphaerella populicola spotting and blotching Appendices

The following related reports are available on request from FIDS.

Detailed seed orchard report, 1992. Forest pest conditions in Pacific Rim National Park, 1992. Forest pest conditions on the Gulf Islands, 1992. Forest pest conditions at Mt. Maxwell Ecological Reserve, 1992. Forest pest conditions at Carnation Creek, 1992. Forest pest conditions at Shawnigan Experimental Plots, 1992. Forest pest conditions in the Vancouver Watersheds, 1992. Forest pest conditions in Provincial Parks, Vancouver Forest Region, 1992.

Detailed copies of aerial survey maps, pest reports, leaflets, monographs and other maps and reports in addition to those listed above are available from the Pacific Forestry Centre upon request.