By Carrie Finkelstein of University of Vermont

Figure 1. My first picture of B. dalhbomii along the Carretera Austral

Upon arriving in Patagonia, the first species that I immediately connected with was Chile’s native bumblebee (Bombus dahlbomii). On the drive from Coyhaique to Cochrane, we stopped at a sustainable farmstead to get some veggies for the first week at basecamp. While I was roaming around the farm, I was instantly drawn to these large orange fuzzy buzzing bees. Apparently, I was so intrigued that I fell into a waist high pit in the process of taking a picture (Figure 1). The moment we got access to wifi, I decided to dig a bit deeper on this species and my interest only grew.

Figure 2. Size comparison of B. dalhbomii worker and queen to invasive B. terrestris (PC: Jose Montalva)

B. dahlbamii is generally described as a relatively large red-orange bee with long bristles covering the thorax and abdomen. This gives the bee an incredibly fuzzy appearance; this characteristic coupled with its size gave the species the nickname “flying mouse” (Johnston, 2014). The “flying mouse” is endemic to Patagonia and is typically found in forest environments with both a continuous and scattered distribution of plants. From my own personal observations, I only noticed B. dahlbamii in the more northern regions of Patagonia. While in the Chacabuco Valley, I didn’t see any of the native bumble bee species, but did notice an abundance of the large earth bumblebee (Bombus terrestris). This invasive species, along with the ruderal bumblebee (Bombus ruderatus), are linked to the decline of B. dahlbomii (Figure 2). Both B. terrestris and B. ruderatus, are much more efficient in terms of migration and foraging ranges when compared to the native species and have outcompeted B. dahlbomii in much of their natural range (Polldori, 2014). Similar to many Bombus spp. the Chilean bumblebee follows a monogamous colony cycle that only involves one queen. However, the period of colonization and reproduction occurs much later in the season than its exotic counterparts, creating a further competitive disadvantage for B. dahlbomii. 

Text Box: Figure 3. B. dahlbomii pollinating a coneflower in contrast with the bell-shaped flower depicted earlier
Figure 3. B. dahlbomii pollinating a coneflower in contrast with the bell-shaped flower depicted earlier

Despite this disadvantage, the Chilean bumblebee has been shown to be a more efficient pollinator than either B. terrestris or ruderatus; the native species pollinates both a more diverse set of flowers and can travel farther distances (Figure 3). This means, that the loss of B. dahlbomii is not only a cultural loss, but also will have negative cascading ecological effects. I hope one day to return to Chile and use my passion for pollinators to further study this species and the impact that it has on the agricultural sector and produce productivity.

References:

Johnston, Ian (2014). “Bye bye big bee: In South America, the world’s largest bumblebee is at risk from imported rivals”. The Independent.

Polidori, C; Nieves-Aldrey, JL (2014). “Comparative flight morphology in queens of invasive and native Patagonian bumblebees (Hymenoptera: Bombus)”. Comptes Rendus Biologies. 338 (2): 126–33. doi:10.1016/j.crvi.2014.11.001. hdl:10261/118107. PMID 25499798.