Special Report 1044 September 2002

CS O S ES'S Unbound issue '5, O. i ci-p-i Does not circulate 73= 0 p ...Q, < Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest

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kr', OCT 2002 OREGON STATE UNIVERSITY LIBRARY EXTENSION SERVICE GON STATE ,UNtVERSiTY t,ORE A-5- 6?12ü2c3\.- This publication is available on the Web at http://eesc.oregonstate.edu

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Marvin Butler Oregon State University Extension Service Jefferson County office 34 SE D Street Madras, OR 97741 Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest M.D. Butler, S.C. Alderman, P.C. Hammond, R.E. Berry, W.J. Johnston, and C.R. McNeal

Kentucky bluegrass (Poa Idaho, residue management as well as other grasses, in pratensis L.) seed is produced may include baling, burning, or the Pacific Northwest on nearly 100,000 acres in the both. (Crawford and Harwood, Pacific Northwest. Dryland This paper summarizes 1959; Kamm, 1971a). It is production occurs in Spokane previously published work considered the most severe County, Washington, and (Butler et al., 2001), in which pest on bluegrasses and Kootenai County, Idaho. The Kentucky bluegrass fields were creeping fescue in northeast major irrigated production surveyed for insects and the Washington (Harwood, areas include the Grande fungal disease ergot. The 1958). Ronde Valley near La Grande association of insects and ergot • The cutworm Protagrotis and Elgin, Oregon; the also was investigated. The obscura is a major pest of Rathdrum Prairie between association of ergot and insects grasses grown for seed in the Spokane, Washington, and in Kentucky bluegrass seed Pacific Northwest, espe- Coeur d'Alene, Idaho; and the production previously had not cially in the Grande Ronde Madras and Culver areas in been investigated. Valley (Kamm, 1982). The central Oregon. All three glassy cutworm (Crymodes irrigated areas are semiarid. Insect pests of devastator) was found in Kentucky bluegrass fields large numbers near Spokane generally are planted in April Kentucky bluegrass in a survey of grass seed or May, although planting Several insect pests are occurs in August in central found on Kentucky bluegrass Marvin D. Butler, Extension crop Oregon. The grass is grown as in the Pacific Northwest. scientist, Oregon State a perennial for 3 to 5 years. • The winter grain mite University; Steve C. Alderman, Harvest of Kentucky (Penthaleus major) can National Forage Seed bluegrass seed begins about the cause severe damage in Production Research Center, first of July in all areas. Kentucky bluegrass fields by Corvallis; Paul C. Hammond, Postharvest residue manage- feeding on plants through Entomology Department, ment in Oregon generally the winter. It is the primary Oregon State University; Ralph includes thermal treatment pest in the Grande Ronde E. Berry, Entomology such as open field burning or Valley and central Oregon. Department, Oregon State treatment with large propane • The sod webworm or cran- University; William J. Johnston, burners. Burning is not allowed berry girdler (Chrysoteuchia Department of Crop and Soil in Washington, and residue topiaria) is a well-known Sciences, Washington State there typically is baled. In pest of Kentucky bluegrass, University; and Craig R. McNeal, field representative, Blue Mountain Seed, Imbler, OR. fields (Crawford and 1998). Host seed is replaced Conidia are released and Harwood, 1959). It is with a hard black body (sclero- accumulate in the plant sap as considered the primary tium) about one to four times it leaks from the wounded cutworm pest in that area larger than normal seed (Alder- ovaries, accumulating in large (Harwood, 1958). Cutworm man, 1991; Barger, 1931; drops. damage frequently occurs in Bove, 1970). Both the disease Insects are believed to play fall and may continue and the sclerotium are com- a role in the spread of ergot through winter and into monly referred to as ergot. (Atanasoff, 1920; Moreno spring. Cutworms can cause Most cultivars of Kentucky et al., 1971; Ingold and significant damage by bluegrass are susceptible to Plunkett, 1979; Lemon, 1992) feeding on the crowns of ergot, although some are more as they feed on conidia- developing plants (Kamm, susceptible than others. Rain- containing honeydew. The 1982). fall or irrigation at the time of sweet syrup is especially • Thrips (e.g., Anaphothrips flowering promotes the devel- attractive to flies (Atanasoff, obscurus) (Kamm, 1971b) opment of ergot. High soil 1920; Barger, 1931; Ingold and and fly larvae of the genus moisture conditions support the Plunkett, 1979; Lemon, 1992), Chloropidae (Starks and development of fruiting bodies wasps (Polistes spp.) (Hardy, Thurston, 1962) can cause and subsequent production and 1988), and nocturnal moths silvertop. Silvertop refers to release of spores (ascospores). (Moreno et al., 1971). The bleached, whitish, or silver- The tiny, threadlike ascospores presence of conidia in the colored dead panicles, move through the air like fine honeydew makes it no less resulting from damage to the particles of dust, easily carried attractive to insects. panicle stalks. Grass seed by the slightest air current. During feeding, conidia are fields occasionally are Ascospores that contact flower consumed by the insects and treated to control thrips stigmas germinate and infect pass intact through their (Anaphothrips spp. and the flowers. digestive tract, with no appar- Aptinothrips spp.) and other During infection of Ken- ent harm to the insect. Honey- potential pests such as tucky bluegrass flowers by dew and conidia also stick to leafhoppers (cicadellids) and C. purpurea, plant sap exudes mouthparts, legs, and other the English grain aphid from the infected ovaries body parts. When insects then (Sitobion avenae). (Luttrell, 1980). This exudate is land on healthy flowers, they • A grass bug (Labops commonly referred to as can transfer conidia to the hesperius) is considered a "honeydew" because of its high flower stigmas or ovary, minor pest but has been sugar content (Barger, 1931; providing opportunity for new reported to cause serious Bove, 1970; Mower and infections and, in turn, new damage to grass leaves in Hancock, 1975). Claviceps sources of honeydew. This seed fields near Spokane interferes with the normal association is of mutual benefit (Harwood, 1958). wound-healing process that to the insect and the fungus. occurs when plant tissues are Ergot on Kentucky cut or damaged. The result is Methods and continuing seepage of sap bluegrass through the infection site. materials In addition to insect pests, The honeydew contains Kentucky bluegrass fields Kentucky bluegrass often is large numbers of fungal spores in the Rathdrum Prairie, Idaho; infected with ergot, a disease (conidia) that are produced on central Oregon; and the Grande caused by the fungus Claviceps the surface of the ovary during Ronde Valley, Oregon, were purpurea (Alderman et al., the early stages of infection. sampled for insects, ergot

2 • Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest sclerotia, and honeydew from from grass heads and foliage. honeydew, and the percentage 1996 to 1998. Three Kentucky The aphid sampler consisted of of panicles with sclerotia were bluegrass seed fields in each a cylinder (16 inches in diam- recorded. region were sampled during eter x 20 inches tall) with a 1996 and 1997. In two of the handle on each side near the lid Detecting ergot on insects regions in 1998, only two fields for shaking. Grass foliage was To quantify the association were sampled. Fields were placed on an 0.25-inch mesh of insects and ergot, a second sampled 1 week or less before screen inside the shaker and collection was made at each harvest to coincide with peak exposed to methyl ethyl ketone site using a modified sweep net occurrence of ergot sclerotia to relax the insects and make it and aphid sampler. In both and honeydew. easier to separate them from cases, sticky cards were used to Varieties sampled each year the foliage during shaking. prevent cross contamination on the Rathdrum Prairie were Insects were collected in a and enable individual insects to `Shamrock,' `Midnight,' and jar at the base of the shaker and be evaluated for the presence `Plush.' In central Oregon, transferred to vials containing of ergot honeydew and conidia. `Coventry' and 'Gnome' were ethyl alcohol. Insects were The sweep net was modi- sampled in 1996; 'Coventry,' identified, and the number of fied with a sticky card mounted `Georgetown,' and 'Merit' in specimens of each species was at the end of a handle and 1997; and 'Georgetown' and recorded. enclosed in an 0.25-inch mesh `Coventry' in 1998. In the Moths were sampled with a hardware cloth cylinder Grande Ronde Valley, the single black light trap placed 10 inches in diameter. Insects varieties sampled included 100 feet from the edge of each passed through the mesh and `Bristol' and 'Coventry' in field at dusk. Moths were were collected on the sticky 1996; `Sidekick,' `Nassau,' and collected the following morn- card, permitting sweeps to be `Ascot' in 1997; and 'Fairfax' ing. A Bio-Strip fumigant strip taken without contamination and 'Nassau' in 1998. (2.5 inches x 6.5 inches) by foliage and associated impregnated with dichlorvos honeydew. Insect collection and was placed in the bottom of the The modified aphid sam- identification traps to kill the moths. Speci- pler consisted of a sticky card Insects were sampled with mens were mounted and in the bottom of a straight- a sweep net, an aphid sampler identified. sided 5-gallon plastic bucket (Gray and Schuh, 1941), and with a collecting jar at the universal black light traps. Sampling Kentucky bottom. This allowed indi- Most of the insects were bluegrass for ergot vidual insects to fall directly collected with a 14-inch sweep Grass seed heads were onto the sticky card. net. Insects collected by both collected during 1997 and 1998 For moth collection, two the sweep net and aphid to determine the amount of sticky cards were attached to sampler were taken from each honeydew and ergot sclerotia the outer edge of the collection of four quadrants in each field. present in each field. Using a bucket so that individuals could A representative series of finger knife, 100 samples of be collected as they approached individuals of each insect grass panicles were randomly the black light trap. species collected was pinned collected by hand from a single For ergot assessment, a and identified with the location area (100 feet x 100 feet) in drop of water was placed on and date of collection. each field. The total number of the mouthparts of insects The aphid sampler was sclerotia per sample, the attached to the sticky cards to used to collect small insects percentage of panicles with wash off any conidia. The drop was removed, mounted on a

Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest • 3 glass slide and examined for leafhoppers and thrips were Ergot conidia were found ergot conidia. Since species collected in the greatest num- on 40 to 100 percent of moths identification on sticky cards bers; in central Oregon, thrips (Table 4). In 13 of 15 collec- was difficult, insect identifica- were most common; and low tions, the percentage of tion to the species level was not numbers of aphids and leafhop- moths with conidia exceeded attempted. pers were collected in the 67, indicating a strong associa- Grande Ronde Valley. How- tion between moths and ergot. Results ever, the number of thrips Conidia also were found on collected in the Grande Ronde flies, leafhoppers, and thrips. Insects collected Valley in 1998 (184) may raise Of the 30 species of insects concerns about silvertop. The Discussion collected in sweep nets and the number of aphids generally aphid sampler, 4 were pests or was less than the number of Insect—ergot relationships potential pests on grass seed, leafhoppers or thrips. A relationship between the 10 were beneficial, and Night-flying moths presence of ergot in a field and 15 were classified as casual included grass-feeding cut- the percentage of moths, flies, visitors or pests on other crops worms (Table 3). Protagrotis leafhoppers, or thrips with (Table 1). Pests or potential obscura was the most common ergot conidia was not estab- pests on Kentucky bluegrass cutworm species of those lished. Fields with higher seed included the sod web- known to be pests in grasses levels of ergot did not necessar- worm, aphids, thrips, and grown for seed, and it was ily have insect populations with leafhoppers. The sod webworm present in all sampled fields. high levels of ergot or was the only serious insect pest Significantly different cutworm honeydew. on grasses that was collected in complexes were collected from sweeps from all three locations. the three growing areas. For Insect populations Beneficial predators example, Agroperina dubitans A rich diversity of insects included the lady beetle was collected from all fields in was collected in grass fields at (Hippodamia spp.), minute Idaho, but from only one field all three locations (Table 1). pirate bug (Orius tristicolor), in Oregon. The glassy cutworm The majority of insects were big-eyed bug (Nysius spp.), (Crymodes devastator) was collected using the sweep net. damsel bug (Nabis spp.), and common in samples from the However, aphids, thrips, and common green lacewing Oregon sites, but was found at leafhoppers were collected (Chrysoperla plorabunda). only one field in Idaho. more effectively using the Parasitic insects included aphid sampler, and moths braconid and ichneumon Presence of ergot and (other than the sod webworm) wasps. The most abundant honeydew on insects and were collected at night with beneficial insects collected in Kentucky bluegrass universal black light traps. sweep nets across the three Results from this project The amount of ergot regions were big-eyed bugs, and discussions with industry sclerotia and honeydew on damsel bugs, ichneumon representatives suggest there grass panicles varied among wasps, and lady beetles. are significant differences in fields (Table 4). The number of The average number of insect pests among the three sclerotia per 100 panicles aphids, leafhoppers, and thrips growing areas. The winter ranged from zero to 565, and collected from grass foliage grain mite, cutworms, and the ergot was found in all fields samples in the aphid sampler sod webworm are important except on the variety was relatively low across pests on grass fields in the `Georgetown' in 1998 locations and years (Table 2). Grande Ronde Valley. The (Table 4). On the Rathdrum Prairie, continues on page 8

4 • Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest Table 1.—Number of fields in which each insect type was collected with a sweep net. Rathdrum Prairie, ID Central Oregon Grande Ronde Valley, OR 1996 1997 1998 1996 1997 1998 1996 1997 1998 3 fields 3 fields 3 fields 3 fields 3 fields 2 fields 3 fields 3 fields 2 fields Common pests on grass seed Butterflies, moths (Lepidoptera) Sod webworm (Pyralidae) 3 3 3 2 1 0 1 1 3 Beneficial predators and parasites Beetles (Coleoptera) Ground beetle (Carabidae) 0 0 1 0 0 0 0 0 0 Lady beetle (Coccinellidae) 2 2 2 3 1 2 0 1 1 Rove beetle (Staphylinidae) 0 0 0 1 0 0 0 0 1 True bugs (Heteroptera) Minute pirate bug (Anthocoridae) 0 2 0 0 0 0 0 0 0 Big-eyed bug (Lygaeidae) 3 1 3 3 2 2 3 3 2 Damsel bug (Nabidae) 3 0 2 3 3 2 3 2 2 Wasps, bees, ants (Hymenoptera) Braconid wasp (Braconidae) 2 0 0 1 0 1 2 0 0 Ichneumon wasp (Ichneumonidae) 1 3 3 1 3 1 2 3 3 Lacewings (Neuroptera) Green lacewing (Chrysopidae) 0 0 0 1 0 0 0 0 0 Damselflies, dragonflies (Odonata) Damselfly (Coenagrionidae) 0 0 0 1 0 0 0 1 0 Casual visitors/pests on other crops Beetles (Coleoptera) Seed beetle (Bruchidae) 0 0 1 o 0 0 0 0 0 Leaf beetle (Chrysomelidae) 0 1 0 0 0 0 1 2 1 Flies (Diptera) 3 3 3 3 3 2 3 3 2 True bugs (Heteroptera) Plant bugs (Miridae) Calocoris 0 0 1 o o 0 0 0 0 Hoplomachus 2 3 2 o o 0 0 0 0 Lygus 2 0 0 1 1 0 0 1 0 Megaloceroea 1 3 1 1 0 0 0 1 0 Monosynamma 1 3 3 o 0 0 1 1 0 Stenodema 0 2 0 0 0 0 0 3 1 Stink bug (Pentatomidae) 0 2 1 0 0 0 0 0 0 Scentless plant bug (Rhopalidae) 0 0 0 2 0 0 1 0 0 Shield-backed bug (Scutelleridae) 2 2 3 0 0 0 0 2 1 Planthoppers (Homoptera) Froghopper (Cercopidae) 0 1 3 0 1 0 0 0 1 Delphacid planthopper (Delphacidae) 0 0 2 1 2 1 1 1 1 Grasshoppers, katydids (Orthoptera) Grasshopper, katydid (Acrididae) 2 0 0 0 0 1 2 0 1

Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest • 5

Table 2. Average number of insects per sample from Kentucky bluegrass foliage extracted in sampling can. Number of individuals collected per sample Rathdrum Prairie, ID Central Oregon Grande Ronde Valley, OR 1996 1997 1998 1996 1997 1998 1996 1997 1998 3 fields 3 fields 3 fields 3 fields 3 fields 2 fields 3 fields 3 fields 2 fields

Aphids, leafhoppers (Homoptera) Aphid (Aphididae) 0.8 1.6 1.2 1.1 4.6 1.8 2.5 0.9 2.5 Leafhopper (Cicadellidae) 6.7 37.3 15.5 1.1 4.0 1.1 4.7 24.1 5.8 Thrips (Thysanoptera) Thrips (Thripidae) 1.1 25.1 13.8 0.5 40.3 30.1 0.1 48.3 184.1

Table 3. Number of fields in which each species of grass-feeding cutworm moths was collected in black light traps. Rathdrum Prairie, ID Central Oregon Grande Ronde Valley, OR 1996 1997 1998 1996 1997 1998 1996 1997 1998 2 fields 3 fields 3 fields 1 field 3 fields 2 fields 2 fields 3 fields 2 fields

Soil-surface cutworms Protagrotis obscura 2 3 3 1 3 2 2 3 2 Agroperina dubitans 2 3 3 0 0 0 1 0 0 Crymodes devastator 0 0 1 1 2 2 1 1 0 Apamea amputatrix 0 0 0 0 0 1 2 1 0 Chortodes rufostrigata 0 0 0 0 0 2 0 0 0 Apamea alia 0 0 0 0 0 0 0 0 1 Agroperina lateritia 0 0 0 0 0 0 1 0 0

Climbing cutworms Aletia oxygala 0 0 0 1 0 0 2 2 2 Leucania farcta 0 0 0 1 1 1 1 0 0

6 • Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest Table 4.—Association of ergot conidia with various insects collected from Kentucky bluegrass fields during 1997 and 1998 and level of ergot present in the fields. Sclerotia Percentage of insects with ergot conidia per 100 Percent panicles Moths Flies Leafhoppers Thrips panicles' Sclerotia Honeydew % Total2 % Total % Total % Total Rathdrum Prairie, ID 1997 `Shamrock' 20 12 7 67 (6) 75 (4) 19 (505) 14 (28) `Plush' 65 26 32 80 (10) 63 (8) 60 (216) 32 (142) `Midnight' 151 55 0 81 (16) 35 (23) 13 (15) 6 (66)

1998 `Shamrock' 27 15 6 100 (16) 74 (19) 20 (329) 10 (99) `Plush' 18 9 2 91 (11) 57 (37) 25 (188) 16 (108) `Midnight' 88 33 4 67 (6) 24 (37) 7 (59) 3 (97) Central Oregon 1997 `Coventry' 212 51 4 100 (3) 52 (23) — — 17 (6) `Merit' 122 49 64 100 (16) 69 (70) 42 (12) 34 (29) `Georgetown' 3 1 0 — 11 (9) 0 (15) 3 (96)

1998 `Coventry' 565 87 0 67 (15) 37 (402) 4 (24) 4 (237) `Georgetown' 0 0 0 40 (5) 19 (32) — 6 (17) Grande Ronde Valley, OR 1997 `Ascot' 42 21 1 89 (66) 73 (15) 57 (28) 31 (39) `Nassau' 82 31 22 84 (37) 14 (7) 10 (51) 0 (2) `Sidekick' 4 2 0 100 (31) 60 (5) 39 (28) 6 (16)

1998 `Fairfax' 206 73 30 87 (31) 77 (160) 51 (69) 16 (318) `Nassau' 12 8 1 43 (14) 32 (327) 22 (68) 8 (247)

'Number of ergot sclerotia based on single 100-panicle sample per field. 2Total number of individuals examined.

Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest • 7 winter grain mite is the major Flies were the only casual agricultural areas throughout pest in central Oregon, with the visitor or pest of other crops the Northwest, was collected at sod webworm only occasion- that were found consistently in every site in this study. How- ally reaching treatable levels. any significant number in ever, it is scarce or absent in On the Rathdrum Prairie, the Kentucky bluegrass fields surrounding natural habitats. In sod webworm is considered the across the three regions. Other a subsequent quantitative study only major insect pest. insects considered casual of grass-feeding cutworms in Aphids were not found to visitors or noncrop pests Kentucky bluegrass seed be an economically important included grasshoppers, seed fields in central Oregon and the pest during the course of this and leaf beetles, and a variety Grande Ronde Valley, study (Table 2), but the English of plant bugs. P. obscura made up grain aphid (Sitobion avenae) The diversity of night- 99.4 percent of the 30,000 was found in fields in all three flying moths varied substan- moths collected (Butler and regions. Although not normally tially between the Rathdrum Hammond, 2001). The remain- considered a pest of grasses, Prairie, central Oregon, and the ing 0.6 percent included 11 this aphid can cause economic Grande Ronde Valley (Table 3). different species. injury to cereals in some years. P obscura was collected from A preliminary comparison Anaphothrips spp. and every field across the three of burning and nonburning Aptinothrips spp. seemed to be growing regions. A. dubitans residue management conducted the most common genera of was common only on the in the Grande Ronde Valley thrips collected. Both can cause Rathdrum Prairie and, along indicated a 64 percent reduc- silvertop symptoms when with P. obscura, was the only tion in P. obscura populations populations feed within the moth species collected in that the year following open field "boot" as the seed head is area, with the exception of burning (Butler and Hammond, developing. However, numbers glassy cutworms (C. devasta- 2002). collected generally were low tor) found in one field. This study indicates that (Table 2) compared to numbers There was much more bluegrass seed production collected in bentgrasses and diversity in Oregon, where nine occurs in an environment fine fescue grasses of western species of grass-feeding moths friendly to beneficial preda- Oregon (Kamm, 1971b), and were collected; six of these ceous and parasitic insects. these pests seemed to be of were found in central Oregon Relatively few insect pests are little significance. and eight in the Grande Ronde associated with bluegrass seed Plant bugs (Stenodema Valley (Table 3). Of the species production. Most routine spp.) also are known to cause collected, seven were soil- insecticide applications are silvertop (Arnott and Bergis, surface feeding cutworms, made in late fall, with applica- 1967). They were collected in while two were climbing tions possible through early low numbers on the Rathdrum cutworms, which often feed on spring, a time when beneficial Prairie and in the Grande flowers and seed heads insects are less active. Popula- Ronde Valley, but were absent (Crumb, 1956; Kamm, 1982). tions of beneficials increase in from central Oregon samples. Only soil-surface feeding the absence of insecticides Silvertop was not a prob- cutworms were found at the during late spring through early lem in the fields sampled, but Idaho site, and they were the summer, negating the need for has been reported to occur in most abundant cutworm at the insecticide applications during Kentucky bluegrass in the Oregon sites (Table 3). development and maturity of Northwest (Crawford and obscura, a generalized Kentucky bluegrass seed. The Harwood, 1959; Kamm, cutworm that often is avoidance of pesticides during 1971b). extremely abundant in late spring to summer not only

8 • Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest increases populations of It is interesting to note the • Silvertop was not a factor in beneficials but provides a similarities between Kentucky the fields sampled, and habitat that facilitates an bluegrass seed production and generally low levels of the ecologically desirable increase a mountain meadow habitat. thrips that cause the symp- in insect diversity overall. Common elements generally toms were collected. The moth Chortodes include adequate water through • The moth Chortodes rufostrigata, a casual visitor seed set, with moist conditions rufostrigata, collected in collected in fields at both and a large amount of central Oregon fields, central Oregon locations during vegetative production. In both previously had been 1998, previously had been situations, the grass is allowed collected only from moun- collected only in wet meadows to produce seed and then dry tain meadows in the Blue in the Blue and Wallowa down during mid- to late and Wallowa mountains of mountains of northeast Oregon summer, followed by fall rains northeast Oregon and from and in one isolated case in (or late-summer irrigation) and Lake County in south- Lake County in south-central cold winters. central Oregon. It is not Oregon. These first-time considered a potential pest. collections in central Oregon Conclusions indicate a significant range Key findings from this References cited extension for this species project include the following. Alderman, S.C. 1991. Aerobi- within Oregon. Quite possibly, • A large diversity of insects is ology of Claviceps purpurea the irrigation of bluegrass seed present in Kentucky blue- in Kentucky bluegrass. Plant fields duplicates the normal grass fields in the Pacific Dis. 75:1038-1041. wet meadow habitat of this Northwest, most of which Alderman, S.C., D.D. Coats, species, allowing a naturally are casual visitors or benefi- F.J. Crowe, and M.D. Butler. very rare species, which cial insects. 1998. Occurrence and normally inhabits mountain • Pests or potential pests vary distribution of ergot and meadows, to invade and among growing areas. Pests estimates of seed loss in successfully establish in include the sod webworm, Kentucky bluegrass grown irrigated grass seed fields at cutworms, and winter grain for seed in central Oregon. much lower elevations. mites. Aphids, thrips, and Plant Dis. 82:89-93. Central Oregon bluegrass leafhoppers are potential Arnott, D.A. and I. Bergis. fields occupy areas that for- pests. 1967. Causal agents of silver merly were a sagebrush- • Protagrotis obscura was by top and other types of bunchgrass habitat, but moths far the dominant cutworm damage in grass seed crops. that normally live in this native species collected. Can. Entomol. 99:660-670. habitat were not found in the • Ergot sclerotia and honey- Atanasoff, D. 1920. Ergot of grass fields. The replacement dew were found in nearly all grains and grasses. Stenciled of native desert with irrigated the fields sampled, and ergot and distributed by USDA bluegrass fields has resulted in conidia were collected from Bureau of Plant Industry, a total replacement of native moths, flies, leafhoppers, Office of Cereal Investiga- cutworm moths. With the and thrips. However, a tions. 127 pp. exception of P. obscura, all of relationship between the Barger, G. 1931. Ergot and the grass-feeding moths col- level of ergot infection in the ergotism. Gurney and lected are typical of moist field and the number of Jackson, London, United habitats and are common at insects carrying ergot Kingdom. 279 pp. higher elevations of the Blue conidia was not established. Mountains and Cascade Range.

Insects and Ergot in Kentucky Bluegrass Seed Production Fields in the Pacific Northwest • 9 Bove, F.J. 1970. The story of Crumb, S.E. 1956. The larvae Kamm, J.A. 1971b. Silvertop ergot. S. Karger, Basel, of the Phalaenidae. USDA of bluegrass and bentgrass Switzerland. 297 pp. Tech. Bull. No. 1135, produced by Anaphothrips Butler, M.D., S.C. Alderman, 356 pp. obscurus. J. Econ. Entomol. P.C., Hammond, and Gray, K.W. and J. Schuh. 1941. 64:1385-1387. R.E. Berry. 2001. Associa- A method and contrivance Kamm, J.A. 1982. Protogrotis tion of insects and ergot for sampling pea aphid obscura Barnes and (Claviceps purpurea) in populations. J. Econ. McDunnough (Lepidoptera: Kentucky bluegrass seed Entomol. 34:411-415. Noctuidae): A pest of grasses production fields. J. Econ. Hardy, T.D. 1988. Gathering of grown for seed in the Pacific Entomol. 94:1471-1476. fungal honeydew by Polistes Northwest. Pan-Pacific Butler, M.D. and P.C. spp. (Hymenoptera: Entomol. 58:73-8. Hammond. 2001. Grass- Vespidae) and potential Lemon, K.M. 1992. Dispersal feeding moths collected in transmission of the causal of the ergot fungus commercial Kentucky ergot fungus. Florida Claviceps purpurea by the bluegrass fields of central Entomol. 71:374-376. lauxaniid fly Minettia and eastern Oregon, 2000. Harwood, R.F. 1958. Sugges- lupulina. J. New York State In: 2000 Seed Production tions for controlling insects Entomol. Soc. 100:182-184. Research at Oregon State affecting grasses grown for Luttrell, E.S. 1980. Host- University, USDA-ARS seed. Extension Bulletin parasite relationship and Cooperating, Ext/CrS 115. EM 1918. Washington development of the ergot pp. 45-48. Cooperative Extension sclerotium in Claviceps Butler, M.D. and Service, Pullman. purpurea. Can. J. Bot. P.C. Hammond. 2002. Ingold, C.T. and B.E. Plunkett. 58:942-958. Grass-feeding moths col- 1979. An epidemic of Moreno, R., V.D. Pederson, lected in Kentucky bluegrass Entomopthora on flies and and J.T. Schultz. 1971. seed fields treated with post- its relationship with the Transmission of Claviceps harvest burning or bale only sphacelia stage of Claviceps. purpurea (Fr.) conidia by the in the Grande Ronde Valley, Bull. Brit. Mycological Soc. cabbage looper moth 2001. In: 2001 Seed Produc- 13:35-37. Trichoplusia ni (Hubner). tion Research at Oregon Kamm, J.A. 1971a. Environ- Proc. of the North Dakota State University, USDA- mental biology of a cran- Acad. Sci. 24:11-14. ARS Cooperating, Ext/CrS berry girdler Crambus Mower, R.L. and 121. pp. 86-87. tutillus (Lepidoptera: J.G. Hancock. 1975. Crawford, C.S. and Crambidae). Entomol. Exp. Sugar composition of ergot R.F. Harwood. 1959. Lepi- and Appl. 14:30-38. honeydews. Can. J. Bot. doptera associated with 53:2813-2825. grass grown for seed in Starks, K.J. and R. Thurston. eastern Washington. J. Econ. 1962. Silver top in blue- Entomol. 52:966-969. grass. J. Econ. Entomol. 55:865-867.

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Published September 2002.