|Pitts Singer, Theresa|
|TROSTLE, GLEN - Retired ARS Employee|
Submitted to: Journal of Insect Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2014
Publication Date: 5/18/2014
Citation: Pitts Singer, T., Cane, J.H., Trostle, G. 2014. Progeny of Osmia lignaria from distinct regions differ in developmental phenology and survival under a common thermal regime. Journal of Insect Physiology. 67:9-19.
Interpretive Summary: Some insect species, including some bees, are broadly distributed across a continent. If insects are transported for beneficial purposes to new geographic locations, or if insects are exposed to unprecedented climatic change, then studies are needed to determine variation in how the insect develops through its immature stages to its adult stage. Those developmental changes may be matched specifically to different climates within the species range. The solitary blue orchard bee is widely distributed across the United States and adjacent Canada. Populations can be managed for pollination of some orchard crops. We examined the development and survival of blue orchard bee offspring of populations that were trapped from Utah, Washington, and California and then reared under fluctuating temperature programs that mimicked the climate of a California almond-growing region. We found that California offspring had longer development durations, burned more of their energy sources during their “quiet” stages, and better survival under California conditions than those from other regions. Developmental life cycles of Washington and Utah offspring were similar. Managing cocooned adult bees under specified cold temperature programs meant that the bees emerged from their cocoons faster and were able to live longer than bees remaining at the mimicked California program that remained warm through part of the winter. Although offspring of blue orchard bee populations from different locations show some ability to adapt in their immature development when exposed to the California climate, they did not fully adapt to the new conditions and maintained the overall immature development timing that is expected for the geographic location from which their parents originated.
Technical Abstract: Some insect species, including some bees, have extensive subcontinental distributions. If insects are transported for beneficial purposes to new geographic locations, or if insects are subjected to unprecedented climatic change, then studies are needed to determine variation in developmental physiology that accommodates different climates within distributional ranges. The solitary bee Osmia lignaria (Hymenoptera: Megachilidae) is widely distributed across the United States and adjacent Canada. Populations can be managed for pollination of some orchard crops. We examined the development and survival of O. lignaria progeny of populations sourced from Utah, Washington, and California and then reared under thermal regimes simulating the climate of a California almond-growing region. We found that California progeny had longer development durations, higher metabolic activity, and better survival under California conditions than those from other regions. Developmental physiologies of Washington and Utah progeny were similar, although some differences were found. Managing cocooned adult bees under prescribed thermal regimes resulted in faster emergence and longer survival times than bees remaining at the California regime. Although progeny of O. lignaria populations from different locations exhibited some acclimatory plasticity in developmental phenologies to an unmatched climatic regime, their overall adaptability was constrained to those expected of their geographic origins.