The western conifer seed bug, Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) is an important pest of conifer seed orchards in western North America. In laboratory studies, we tested the feeding and oviposition activity of adult L. occidentalis when presented with four different hosts from the inter-mountain western United States and also tested the survival and development of nymphs when confined to these individual hosts. Adult L. occidentalis preferentially fed on pine hosts over non-pine hosts, and females oviposited on ponderosa pine more frequently than on any other surface. L. occidentalis nymphs survived the longest and were most likely to complete development on second-year cones of lodgepole pine. Survival of nymphs was shortest in non-fed control, water-only and first-year pine cone treatments, none of which resulted in maturation to adulthood. Pine foliage was preferred as an oviposition site over the non-pine material and was more suitable for maturation compared with non-pine hosts. The differences between our results and those of prior reports are discussed in terms of phylogenetic distance between Douglas-fir in inland versus coastal areas, potential for seasonal shifts in host preference over the course of a summer and the potential adaptations by the insect in various geographic areas.
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