Examining Historical Rates of Leafcutting Bee Brood Cell Pathogens, Parasitoids, and Predators to Establish Baseline...

Area of Science:

• Entomology
• Agricultural Science
• Apiculture

Background:

• The alfalfa leafcutting bee (Megachile rotundata) is vital for alfalfa seed production.
• Solitary nesting bees are susceptible to pathogens, parasitoids, and predators during development.
• Invertebrate pests and fungal pathogens pose significant threats to commercial alfalfa seed growers.

Purpose of the Study:

• Establish baseline rates of pathogens, parasitoids, and predators in M. rotundata brood cells.
• Develop management cutoffs to guide growers on purchasing new bee stocks.
• Compare pest and disease prevalence between grower-produced and newly purchased bee stocks.

Main Methods:

• Utilized historic data from the Parma Cocoon Diagnostic Laboratory.
• Analyzed rates of chalkbrood, predators, and parasitoids in M. rotundata brood cells.
• Compared samples from U.S. grower stocks and Canadian bee suppliers.

Main Results:

• Provided historic averages for chalkbrood, predators, and parasitoids.
• Observed a significant increase in chalkbrood and predators between 2007-2011.
• Found significant differences in chalkbrood and predator rates between Canadian and U.S. grower stocks.

Conclusions:

• Historic data analysis informs management decisions for alfalfa leafcutting bees.
• Increased reliance on domestic bee stocks may correlate with higher infection rates.
• Understanding pest and disease dynamics is essential for maintaining healthy bee populations for pollination.