Captive Rearing Success and Critical Thermal Maxima of Bombus griseocollis (Hymenoptera: Apidae): A Candidate for Commercialization?

<p><em>Commercialized bumble bees (Bombus) are primary pollinators of several crops within open field and</em></p> <p><em>greenhouse settings. However, B. impatiens is the only species widely available for purchase in North</em></p> <p><em>America. As an eastern species, concerns have been expressed over their transportation outside of their</em></p> <p><em>native range. Therefore, there is a need to identify regionally appropriate candidates for commercial crop</em></p> <p><em>pollination services, especially in the western U.S.A. In this study, we evaluated the commercialization</em></p> <p><em>potential of B. griseocollis, a broadly distributed species throughout the U.S.A., by assessing nest initiation</em></p> <p><em>and establishment rates of colonies produced from wild-caught gynes, creating a timeline of colony</em></p> <p><em>development, and identifying lab-reared workers&rsquo; critical thermal maxima (CT</em><em>Max</em><em>) and lethal temperature</em></p> <p><em>(ecological death). From 2019 to 2021, 70.6% of the wild-caught B. griseocollis gynes produced brood in a</em></p> <p><em>laboratory setting. Of these successfully initiated nests, 74.8% successfully established a nest (produced a</em></p> <p><em>worker), providing guidance for future rearing efforts. Additionally, lab-reared workers produced from wildcaught</em></p> <p><em>B. griseocollis gynes had an average CT</em><em>Max </em><em>of 43.5&deg;C and an average lethal temperature of 46.4&deg;C,</em></p> <p><em>suggesting B. griseocollis can withstand temperatures well above those commonly found in open field</em></p> <p><em>and greenhouse settings. Overall, B. griseocollis should continue to be evaluated for commercial purposes</em></p> <p><em>throughout the U.S.A.</em></p>