Bombus pensylvanicus




Pollination is directly responsible for the reproduction of plants, which has great economic impact on the availability of plants for commercial purposes (Pollinator Partnership 2013). Pollination is a mutualistic relationship between the Bombus pensylvanicus and certain flowering plant species; the bumble bee receives food (nectar) from the flower and the bee in return proliferates the plants genetic material. The American Bumble Bee, specifically, will often pollinate Agave lechuguilla, coneflowers, rough blazing star, Morning Glory, yellow fringeless orchid, tall ironweed, red clover, Queen Anne’s Lace and Sunflowers (Encyclopedia of Life 2013).


            The decline of Bombus pensylvanicus is of concern because of their ecological role as pollinators. Though there is no conclusion as to a concrete explanation for the American Bumble Bees' decline, there are strong suggestions that it could be attributed to the parasite Nosema bombi—an ”obligate intracellular microsporidian parasite” (Cameron et al. 2011). A study published in the Journal of Invertebrate Pathology tested the effects of N. bombi on bumble bee fitness. An infected queen will pass the pathogen onto future generations (Otti and Schmid-Hempel 2007).  Although it seems to have no effect on her reproductive success, it decreases the sperm count and survival rates of her male offspring, which in turn reduces the number of males for the daughter queens to mate with and the reproductive success of the colony (Otti and Schmid-Hempel 2007). Spores of N. bombi are introduced into the environment by the feces or decaying body of an infected host; the spores then infect other individuals as a susceptible organism ingests the spores (Ottie and Schmid-Hempel 2007). Other bumble pathogens to note are Apicys tisbombi, Crithidia bombi, Crithidia expoeki, Locustacarus buchneri (Meeus et al. 2011).