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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Insect Genetics and Biochemistry Research » Research » Publications at this Location » Publication #354928
Title: Monoculture vs. non-monoculture effects on reproductive performance of the alfalfa leafcutting bee, Megachile rotundata

Author
item EARLS, KAYLA - North Dakota State University
item PORTER, MONIQUE - Pennsylvania State University
item Rinehart, Joe
item GREENLEE, KENDRA - North Dakota State University

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/25/2018
Publication Date: 11/11/2018
Citation: Earls, K.N., Porter, M., Rinehart, J.P., Greenlee, K.J. 2018. Monoculture vs. non-monoculture effects on reproductive performance of the alfalfa leafcutting bee, Megachile rotundata [abstract]. 2018 Entomology Society of America/Entomology Society of Canada Joint Annual Meeting. Nov 11-14, 2018. Vancouver, British Columbia, Canada. Paper No. D3510.

Interpretive Summary:

Technical Abstract: The alfalfa leafcutting bee, Megachile rotundata, is a pollinator of many agricultural crops, and is extensively managed for use in alfalfa (Medicago sativa) seed production. Female bees depend on flowers for nutrition and offspring provisioning. The quantity and characteristics of offspring, including sex ratios and diapause incidence, are determined by the parental female bee. Female M. rotundata in crop fields are limited to one floral resource, while unmanaged areas provide an array of floral resources. The purpose of this study is to test the hypothesis that increased floral diversity increases reproductive fitness in M. rotundata. Individual female fitness will be measured by the number of offspring, sex ratio, and diapause incidence in a monoculture M. sativa field and in an unmanaged ditch that contains at least four different flowering species. Preliminary data showed a ubiquitous increase of reproductive performance in areas with increasing levels of floral diversity. There was also sex-dependent incidence of diapause, in which male offspring are more likely to enter diapause compared to female offspring. This suggests that mothers are using a bet-hedging strategy and could be a direct result of the parental female bee experiencing a variable environment during adulthood. Female offspring require more resources to produce, therefore, there is a risk in having large percentages of female offspring to emerge during the late summer when resources could be limited. Comparing the effects of floral landscape composition on reproductive performance and strategy has the potential to aid farmers in increasing bee retention rates and pollination services.