|scientific name Choristoneura pinus |
common name Jackpine budworm
Jack pine (Pinus banksiana) forests.
Adult flight period from late June to mid August.
Fully developed larva 20-23 mm long, has a reddish tan head with dark lateral markings and a dark brown body with two rows of paired spots along its length. Pupa reddish brown with two terminal hooks at hind end (Volney 1994). Forewing of adult rust colored, never gray, and mottled with silver bands and flecks of darker scales. Hind wing entirely dark smoky with white fringe marked by dark basal line. Wing span of females slightly larger in range (15-28mm) than males (18-24mm) (Freeman 1967, Furniss & Carolin 1977, Volney 1994). For more specific information see Freeman (1967).
Variation in color and pattern of the forewing and morphological resemblance among conifer-feeding Choristoneura make it very difficult to distinguish species using external morphological characteristics (Dang 1985). To correctly identify to species it may be necessary to look at other characters such as genitalia (Dang 1985, Dang 1992), mitochondrial DNA (Sperling & Hickey 1995), or to observe behavioural characteristics such as host plant preference, pheromone attraction, or larval diapause. There is a possibility that some of the databased specimens collected from the western part of Alberta are misidentified.
Female adult may lay over 300 lime green eggs in several different egg masses on convex surface of pine needles. Each egg mass typically consists of two rows of eggs which overlap like shingles (Volney 1994). Eggs hatch in 6 to 10 days (Cadogan 1995), the larvae disperse to find overwintering sites under bark scales, spin silken cocoons, molt to second larval instar and then overwinter. In the spring the larvae emerge in late May and early June when the pollen cone buds are swollen in the upper tree crowns. The larvae begin mining the buds. They spin silk webbing and tunnels for protection which they feed within as they move along the buds and eventually along developing foliage and seed cones. Larvae typically finish feeding by mid-July in their seventh instar and pupate within the silk webbing. Pupation lasts approximately 10 days before adult emerges (Volney 1994, Cadogan 1995).
Not of concern.
Feeds principally on jack pine but will also feed on Scots (Pinus sylvestris), lodgepole (Pinus contorta), and red (Pinus resinosa) pine (Volney 1984).
Jack pine forests in Canada from Atlantic provinces to Cypress Hills on the Alberta-Saskatchewan border as well as northern United States from New England to the lake states. First outbreak in Alberta was recorded in 1985 in the central part of the province. Pine feeding budworms are also found in southeastern British Columbia and southwestern Alberta but taxonomic status is uncertain (Harvey 1984, Volney 1994).
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