Title: Bumble bee fauna of Palouse Prairie: survey of native bee pollinators in a fragmented ecosystem Authors
|Hatten, Timothy -|
|Looney, Christopher -|
|Bosque-Perez, Nilsa -|
Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 9, 2014
Publication Date: N/A
Interpretive Summary: A diversity of bumble bee species exists on the Palouse Prairie of eastern Washington and north Idaho. This unique habitat has been heavily fragmented by agricultural intensification over the last century, yet we detected 10 different species over a two-year sampling period. By comparing the survey results to historical records, it was determined that five species that were once present in the region were not detected and another eight decreased from historic population levels in at least one year of the survey. Using ordination analyses, we identified prairie remnant characteristics that correlated to the presence of some species, indicating that preserving various types of remnants at multiple elevations may be critical to preserving the remaining Palouse bumble bee community.
Technical Abstract: Bumble bees are dominant pollinators in the northern hemisphere, providing important pollination services for commercial crops and innumerable wild plants. Nationwide declines in several bumble bee species and habitat loss in multiple ecosystems have raised concern about conservation of this important group. In many regions, such as the Palouse Prairie, relatively little is known about bumble bee communities, despite their critical ecosystem functions. Pitfall trap surveys for ground beetles in Palouse Prairie remnants conducted in 2002-2003 contained considerable by-catch of bumble bees (Hymenoptera: Apidae: Bombus). Effects of landscape context, remnant features, year, and season on bumble bee community composition were examined. Additionally, bees captured in 2002-2003 were compared with historic records for the region to assess changes in relative abundance of individual species. Ten species of bumble bee were captured, representing the majority of the species historically known from the region. Few detectable differences were found among remnants. Community composition differed appreciably based on season, landscape context, and elevation, resulting in different bee assemblages between western, low-lying remnants and eastern, higher-elevation remnants. Results suggest that conservation of the still species-rich bumble bee fauna should take into account variability among prairie remnants, and further work is required to adequately explain bumble bee habitat associations on the Palouse.