Bumble Bees (Hymenoptera: Apidae: Bombus spp.) of Interior Alaska: Species Composition, Distribution, Seasonal Biology, and Parasites

Abstract

BackgroundDespite the ecological and agricultural significance of bumble bees in Alaska, very little is known and published about this important group at the regional level. The objectives of this study were to provide baseline data on species composition, distribution, seasonal biology, and parasites of the genus Bombus at three major agricultural locations within Alaska: Fairbanks, Delta Junction, and Palmer, to lay the groundwork for future research on bumble bee pollination in Alaska.New informationA total of 8,250 bumble bees representing 18 species was collected from agricultural settings near Delta Junction, Fairbanks, and Palmer, Alaska in 2009 and 2010. Of the 8,250 specimens, 51% were queens, 32.7% were workers, and 16.2% were males. The species composition and relative abundances varied among sites and years. Delta Junction had the highest relative abundance of bumble bees, representing 51.6% of the specimens collected; the other two locations, Fairbanks and Palmer represented 26.5% and 21.8% of the overall catch respectively. The species collected were: Bombus bohemicus Seidl 1837 (= B. ashtoni (Cresson 1864)), B. balteatus Dahlbom 1832, B. bifarius Cresson 1878, B. centralis Cresson 1864, B. cryptarum (Fabricius 1775) (=B. moderatus Cresson 1863), B. distinguendus Morawitz 1869, B. flavidus Eversmann 1852 (=B. fernaldae Franklin 1911), B. flavifrons Cresson 1863, B. frigidus Smith 1854, B. insularis (Smith 1861), B. jonellus (Kirby 1802), B. melanopygus Nylander 1848, B. mixtus Cresson 1878, B. neoboreus Sladen 1919, B. occidentalis Greene 1858, B. perplexus Cresson 1863, B. rufocinctus Cresson 1863, and B. sylvicola Kirby 1837. Overall, the most common bumble bees near agricultural lands were B. centralis, B. frigidus, B. jonellus, B. melanopygus, B. mixtus, and B. occidentalis. Species' relative population densities and local diversity were highly variable from year to year. Bombus occidentalis, believed to be in decline in the Pacific Northwest states, represented 10.4% of the overall specimens collected from the three sites studied. Bumble bees were found to be infected by Nosema and nematodes with infection rates up to 2.1% and 16.7% respectively. Of the eight species infected by parasites, B. occidentalis displayed the highest Nosema infection, while B. centralis was the species with the highest infection of nematodes. To our knowledge this represents the first multi-year study on bumble bees from the main agricultural areas of Alaska to provide baseline data on species composition, distribution, seasonal biology, and parasites of the genus Bombus.

Evidence of Bumble Bee Extirpation and Colonization, Galiano Island, British Columbia, Canada

“…Studies have consistently demonstrated blue vane traps to be highly effective at sampling large insects, particularly bumble bees, though additional sampling methods may be required to capture a complete picture of bee communities (Stephen and Rao 2005, 2007; Rao and Stephen 2007; Wilson et al 2008; Geroff et al 2014; Buchanan et al 2017; Gibbs et al 2017; McCravy and Ruholl 2017; Rhoades et al 2017). Studies have also shown blue vane traps to be effective at passively sampling the species concerned in this study, including B. fervidus, B. flavidus, B. insularis , B. occidentalis , and B. suckleyi (Kimoto et al 2012, Pampell et al 2015, Rhoades et al 2016, Gibbs et al 2017, Rivers et al 2018). Nevertheless, additional targeted sampling efforts may be necessary to conclusively establish this case of bumble bee extirpation.…”

“…Our sampling focused on a diverse range of habitats representative of the island landscape (e.g., woodlands, wetlands, clearcuts, rural areas, and gardens, all within a forested matrix), including areas in the vicinity of historical collection sites (Figure 1). Studies have consistently demonstrated blue vane traps to be highly effective at sampling large insects, particularly bumble bees, though additional sampling methods may be required to capture a complete picture of bee communities Rao 2005, 2007 (Kimoto et al 2012, Pampell et al 2015, Rhoades et al 2016, Rivers et al 2018. Nevertheless, additional targeted sampling efforts may be necessary to conclusively establish this case of bumble bee extirpation.…”

Systematic review of cuckoo bumblebee research reveals data gaps and understudied species

“…Concern is also mounting regarding the fate of the cuckoo bumblebees, which not only depend on them but face these same anthropogenic threats. A number of publications have noted the rarity, absence, or decline of cuckoo bumblebees which had previously been recorded (e.g., Colla et al, 2012; Figueroa & Bergey, 2015; Grixti et al, 2009; Pampell et al, 2015; Richardson et al, 2018 in North America; and Kolosova et al, 2016; Kosior et al, 2007; Rasmussen et al, 2022 in Europe)—drawing attention to the need to monitor and assess the status of Psithyrus populations through increased survey efforts. Understanding threats to cuckoo bumblebees and making assessments of their populations, however, requires more than just surveys of their abundance and distribution.…”

Evidence of Bumble Bee Extirpation and Colonization, Galiano Island, British Columbia, Canada

“…Our sampling focused on a diverse range of habitats representative of the island landscape (e.g., woodlands, wetlands, clearcuts, rural areas, and gardens, all within a forested matrix), including areas in the vicinity of historical collection sites (Figure 1). Studies have consistently demonstrated blue vane traps to be highly effective at sampling large insects, particularly bumble bees, though additional sampling methods may be required to capture a complete picture of bee communities Rao 2005, 2007 (Kimoto et al 2012, Pampell et al 2015, Rhoades et al 2016, Rivers et al 2018. Nevertheless, additional targeted sampling efforts may be necessary to conclusively establish this case of bumble bee extirpation.…”