Forest Health Protection and State Forestry Organizations

Febuary 2006 10.3 Western Bug By Sandy Kegley

Leptoglossus occidentalis Heidemann

This can have Hosts: huge seed  Pines production impacts  Douglas-fir in western white  Grand fir pine seed orchards.

Topics Damage Damage 1 The insect feeds by using its all or parts of the contents are Life History 1 long mouthparts to pierce through removed. Cones will develop Identification 2 cone scales into developing . normally but produce no viable seed The insect’s saliva softens or (Hedlin et al. 1981). Partially filled Management 2 dissolves seed contents which are and empty seeds can be detected on Other Reading 3 then imbibed. Type of damage to radiographs of extracted seed. Seed Field Guide the seed depends on the time and bugs can reduce the amount of length of the feeding period. When viable seed by 80% (Connelly and feeding occurs before the seedcoat Schowalter 1991). They can also hardens, the contents of the seed cause abortion of first year conelets are completely removed and the and feed on developing male seedcoat collapses. After flowers, reducing pollen production. Key Points seedcoats harden, the damaged  Seed bugs can seeds do not collapse even though reduce the amount of viable seed by 80% Life History  Type of damage to Adults overwinter in dead weather. There is one generation the seed depends trees, bird or rodent nests, or per year (Koerber 1963). on the time and people’s houses. They become length of the active in the spring and lay barrel- Seed bug feeding period. shaped eggs in rows on the needles barrel- shaped eggs  Monitoring, use of of host trees from May to July. laid in rows synthetic Eggs hatch into nymphs which feed on needles pyrethroid, and on seed in developing cones. They of host tree natural controls pass through 5 nymphal instars and from May to should be used to reach maturity by late August. New July. control large seed adults continue to feed on the bug infestations. ripening cone crop or first year conelets until the onset of cold Page 2 Management 10.3

Identification Adults are active and quite emit an unpleasant odor when conspicuous from spring through disturbed or squished. Adults can fall. They are large—about an inch be quite a nuisance when they enter long with long legs and antennae. buildings in the fall in search of The hind tibia is flattened and overwintering sites. expanded. Their body is reddish brown to dark gray-brown in color with a thin zigzag white line across its forewing. They have orange and black markings on the upper abdomen that are evident when in Photos show adult seed bug flight. Nymphs have brightly colored orange markings. Both adults and nymphs are somewhat gregarious and tend to congregate on branch tips and cones on the sunny sides of trees. Nymphs will hide on the underside of cones or foliage when disturbed. Adults readily fly when disturbed. In flight, adults produce a buzzing Radiograph of seeds damaged by noise. Both adults and nymphs seed bugs.

Chemical insecticide Management registrations for General management options include: insect control change frequently. Monitoring: Contact County, Monitoring seed bug populations in seed orchards can be State, or Federal been done by visually examining cones on trees. pesticide coordinators for Chemicals: updates on When numerous seed bugs are found, insecticides may be current applied to protect seed. The synthetic pyrethroid, insecticide permethrin*, has been used successfully to control seed registrations and bugs in North Idaho western white pine seed orchards. Seed application methods. bug activity may be detected by radiographs, biochemical marker based techniques (Lait et al. 2000, Bates et al. 2002) or staining techniques (Cambell and Shea 1990).

Natural controls: Parasites of seed bug eggs have been identified and could potentially be used in an integrated pest management program in the future (Bates 2004). Page 3 Western Conifer Seed Bug Management 10.3

Other Reading Bates, S. 2004. Parasitoids of occidentalis Heidemann (: ) in British Columbia. Journal of the Entomol. Society of British Columbia. http://www.findarticles.com/p/articles/mi_qa4139/is_200412/ ai_n13510931

Bates, S.L.; Lait, C.G.; Borden, J.H.; and Kermode, A.R. 2002. Measuring the impact of Leptoglossus occidentalis (Heteroptera: Coreidae) on seed production in lodgepole pine using an antibody-based assay. Journal of Economic Entomol. 95 (4): 770-777.

Connelly, A.E. and Schowalter, T.D. 1991. Seed losses to feeding by Leptoglossus occidentalis (Heteroptera: Coreidae) during two periods of second-year cone development in western white pine. J. Econ. Entomol. 84(1): 215-217.

Hedlin, A.F.; Yates, H.O. III; Cibrian-Tovar, D.; Ebel, B.H.; Koerber, T.W.; Merkel, E.P. 1981. Cone and seed of North American . Canadian Forestry Service, United States Forest Service, Secretaria de Agricultura y Recursos Hidraulicos, Mexico. 122 p.

Koerber, T.W. 1963. Leptoglossus occidentalis (, Coreidae), a newly discovered pest of coniferous seed. Annals of the Entomol. Soc. of Amer.56: 229- 234.

Lait, C.G.; Bates, S.L.; Kermode, A.R.; Morrissette, K.K.; Borden J.H. 2000. Specific biochemical marker-based techniques for the identification of damage to Douglas -fir seed resulting from feeding by the western conifer seed bug, Leptoglossus occidentalis Heidemann (Hemiptera: Coreidae). Insect Biochemistry and

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