Author
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Strange, James |
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Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/17/2015 Publication Date: 4/17/2015 Citation: Strange, J.P. 2015. Bombus huntii, Bombus impatiens and Bombus vosnesenskii (Hymenoptera: Apidae) pollinate greenhouse-grown tomatoes in western North America. Journal of Economic Entomology. 108(3):873-879. Interpretive Summary: Bumble bees are important pollinators of tomato plants grown in greenhouses, but currently there is only one bumble bee species available in North America for this purpose. To meet the growing interest in having multiple species to pollinate greenhouse tomatoes the present experiment tested three species of bumble bees as effective pollinators. The Hunt bumble bee and the Vosnesensky bumble bee were compared to the common eastern bumble bee and a control treatment where no bees were added. The three species all pollinated tomatoes effectively and significantly better than the control. The results suggest that these western native bees can be excellent pollinators of tomatoes. Technical Abstract: Bumble bees (Bombus) are the primary pollinators of tomatoes grown in greenhouses and can significantly increase fruit weight compared to tomatoes that receive no supplemental pollination. Due to mounting concerns over the transportation of bumble bees outside of their native ranges, several species native to western North American are currently being investigated as potential commercial pollinators. Here, two western species, Bombus huntii and B. vosnesenskii, are compared to the eastern commercial pollinator, B. impatiens, for their efficacy as pollinators of greenhouse grown tomatoes. In two experiments, colonies were placed in greenhouses and compared to control plants that received no supplemental pollination. In the first experiment, seed set was significantly increased with bumble bee pollination in one variety of cherry tomatoes. In the second experiment comparing the three bumble bee species, fruit weight was improved by all three species over the control, and the number of days to harvest was shorter for bee-pollinated fruit. In some rounds of pollination, differences were found among bumble bees, but these were inconsistent across replicates; however, all bumble bees outperformed control treatment. Additionally, fruit weight was shown to be highly correlated to fruit diameter and seed set in all tests and, thus, is shown to be a reliable metric for assessing pollination in future studies. These results suggest that commercialization of western bumble bees is a viable alternative to the movement of non-native bees into western North America to pollinate tomatoes. |
