Michael K. writes in with a pointer to this doc (.pdf) from the California Department of Food and Agriculture regarding the introduction of the bumblebee Bombus impatiens to California as a crop pollinator. The proposal is in response to a dearth of available honeybees (Apis mellifera) to do the job, due to problems with the Varroa mite (bumblebees are not susceptible to the Varroa mite, but do of course have their own parasites).
The study covers a wide variety of potential positives and negatives that could result from the bumblebee's introduction. A risk assessment done by a consulting firm is included in the appendix. Since the bees are being used for crop pollination, it would be impossible to guarantee that the introduced individuals won't escape into the wild. Instead, the suggestion is to minimize contact through placement only in "highly agricultural areas" and by limiting the duration of their time in the field, including "proper disposal of the colonies after their field use is terminated." Does that mean what I think it means? Sucks to be a bee.
While B. impatiens is native to the eastern USA, it is not considered native to California, which has 24 native Bombus species. This raises an interesting question: Is it better, from an ecological perspective, to have the European honeybee or Bombus terrestris? The bumblebee will be at risk to hybridize with native relatives, though the document claims that the chances of hybridization are minimal (see Appendix p. 17). Other issues to consider are competition for wild pollen and nectar sources, and potential associations between the bees and non-native plants. The risk assessment says "The risk of competition is deemed to be less than significant," in part because the time that the non-native bumblebees would be allowed to forage is limited, and also because of the intention to keep the bumblebees restricted to cropland (see Appendix p. 15).
Public comments on this topic are being accepted through January 19th, 2007. Interested readers can learn more about non-native bumblebees in previous ISW posts.