Life table for Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) and prediction of damage in lodgepole pine seed orchards
1 Fecundity, egg hatch and nymphal survivorship of Leptoglossus occidentalis Heidemann were determined and used to develop a damage prediction formula for seed bugs in lodgepole pine seed orchards.
2 A single overwintered L. occidentalis female may lay up to 80 eggs during early and mid-season cone development.
3 Up to 83.4% of eggs that were attached to branches with tape hatched successfully, compared with 53.5% of eggs attached to needles with wire. Egg parasitism was only observed in egg masses attached with wire.
4 Egg masses attached with wire suffered approximately 30% mortality from parasitism, primarily by Gryon pennsylvanicum (Ashmead).
5 Approximately 15.1 and 2.5% of first instars survived to adulthood in 2000 and 2001, respectively. Survival of caged nymphs that were protected from predators was 14.5 and 17.8%, respectively.
6 A composite survival table indicated that 9.3% of eggs laid by L. occidentalis are expected to survive to adulthood.
7 Based on previously determined damage estimates for each life stage of feeding during three periods of cone development, a hypothetical density of one seed bug per tree early in the season will result in an expected seed loss of approximately 310 seeds.
Document Type: Research Article
Affiliations: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
Publication date: May 1, 2005