RE: [beemonitoring] questions about the effect of managed Osmia lignaria on wild populations
Folks- we are working with developmental tempos and diapause, comparing Osmia lignaria populations drawn from 3 far-flung, different western US climatic regions, building on earlier work at our lab. Sure enough, their progeny differ in local phenological adaptations related to climate when placed in a common incubator environment, in particular responding to summer and winter durations. In some cases the developmental differences are dramatic. In the greenhouse, these traits breed true, and when crossed, an unworkable scramble of phonological traits results. Selection would, I think, sift out these differences for any strays of releases in orchards that bred with local wild populations, although there could be circumstances where large releases could swamp local populations where present, I suppose. But it does argue for climatic matching between source populations and where they are being used, at least for the easiest way to be successful using these bees. This logic of climatic matching has proven key to successful insect biocontrol introductions as well. That is one argument I would make in favor of commercial regionalization of native pollinator sourcing for gardens and farms..
Of much greater concern to me are the parasitic wasps, mites, and diseases that could be shipped around transcontinentally, taxa that are poorly characterized. We could unwittingly introduce new problems to regions that lacked them before. Witness the spread of tracheal mites and Varroa mites by beekeepers around the US . Even the ubiquitous Sapygia wasp parasites of Osmia could be problematic, as the species (whatever they are) have _never_ been evaluated in a taxonomic monograph, so we don’t know with confidence which species occur where. Further, it seems inevitable that Osmia other than O. lignaria could and will be mistakenly shipped outside of their native regions as unrecognized co-nesting species. Osmia californica and O. montana come to mind, both western species that nest nearly concurrent with O. lignaria using the same sized holes. They don’t occur in the eastern US, where some producers are shipping western Osmia lignaria. And of course there are _those_ bees’ diseases and parasites as a further concern. Regional production and shipment would lessen all of these risks and deliver bees better adapted to the user’s own climate, making them much less trouble to use and manage in my experience and opinion.
James H. Cane
USDA-ARS Bee Biology and Systematics Lab
Utah State University , Logan , UT 84322 USA
tel: 435-797-3879 FAX: 435-797-0461