Author
 |
Tripodi, Amber |
|
Strange, James |
|
Submitted to: Insectes Sociaux
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/9/2019 Publication Date: N/A Citation: N/A Interpretive Summary: Like honey bees, bumble bees are social insects, living in colonies composed of a single queen and her worker offspring. However, bumble bee queens start their colonies alone, unlike honey bees. A bumble bee queen lives a solitary existence until her daughters emerge and take over some of the duties of the nest. Little is known about the stages in the solitary phase of bumble bees, including the factors that influence successful initiation of nests. One anecdotal recommendation suggests that wild-caught queens are less likely to initiate nests if they are captured while carrying pollen loads. Queens that are collecting pollen have already chosen a nest site and are either preparing to lay their first clutch of eggs, have already begun laying eggs, or are feeding developing larvae. Although there is a conservation-based argument for leaving these queens to their own devices, we were interested in the biological aspect of this: if a queen has already initiated a nest in the wild, will she initiate another one in captivity? In 2016 and 2017, we captured 960 queens of five species and noted the presence or absence of pollen. We then placed each queen in an artificial nest, gave her unlimited food for 21 days and monitored egg laying daily to compare nesting rates between queens captured with and without pollen loads. Rates varied among species, and pollen-collecting influenced these rates in different ways across species. Queens of the western bumble bee were less likely to lay eggs when they were caught collecting pollen, but two-form bumble bee and yellow-faced bumble bee queens captured with pollen had a greater chance of initiating a nest in captivity. Understanding more about the solitary phase of a bumble bee queen’s life and recognizing that there are differences among species can help us to develop new species as pollinators for agricultural crops. Technical Abstract: Bumble bees are eusocial, yet queens are solitary for a large portion of their lives. Little is known about the stages in the solitary phase of bumble bees, including the factors that influence successful initiation of nests. One anecdotal recommendation suggests that wild-caught queens are less likely to initiate nests if they are captured while carrying pollen loads. Queens that are collecting pollen have already chosen a nest site and are either preparing to lay their first clutch of eggs, have already begun oviposition, or are provisioning developing brood. Although there is a conservation-based argument for leaving these queens to their own devices, we were interested in the biological aspect of this: if a queen has already initiated a nest in the wild, will she initiate another one in captivity? In 2016 and 2017, 960 queens of five species were captured, and the presence or absence of corbicular loads of pollen was noted. Each queen was then placed in an artificial nest and provided with unlimited food for 21 days. Nests were monitored for brood presence daily, and rates of nest initiation (brood production) were compared between queens captured with and without pollen loads. Nest initiation rates varied among species, as did the influence of pollen-collecting behavior at the time of capture. Pollen-laden Bombus occidentalis queens were less likely to lay eggs, yet B. bifarius and B. vosnesenskii queens with pollen had a greater chance of initiating a captive nest. |
