2008 Volume 43 Issue 1 Pages 19-23
Commercial colonies of European bumble bee, Bombus terrestris, have been widely used for pollinating tomato plants in greenhouses in Japan; however, a wild colony of the species was found in Hokkaido in 1996, after which several studies were conducted to investigate the ecological impact of the naturalization of B. terrestris to Japanese ecosystems. To quantify the status of naturalization, it is necessary to establish a method for estimating the population size of the alien bees established in the field. Locating bumble bee colonies in the field is, however, very difficult because they usually nest underground. In this study, we estimated the number of colonies using genetic data from B. terrestris queens foraging near greenhouses in Biratori, Hokkaido, Japan, applying the Shared Loci Correspondence Analysis (SLCA). Sampled 39 queens were assigned to 30 different families, which indicates that most queens came from different colonies. Based on the findings, we discuss the importance of urgent measures to prohibit B. terrestris from escaping from greenhouses and becoming naturalized in Hokkaido.
