Pest Management Science (2020) 76, 2627-2634

Guoxiong Peng, Sen-Miao Tong, Deyu Zeng, Yuxian Xia and Ming-Guang Feng (2020)
Colony heating protects honey bee populations from a risk of contact with wide-spectrum Beauveria bassiana insecticides applied in the field
Pest Management Science 76 (8), 2627-2634
Abstract:
BACKGROUND
The safety of fungal insecticides to apiculture is a public concern but remains poorly understood. This study seeks to evaluate whether, how and why wide-spectrum Beauveria bassiana insecticides are safe to honey bees in a novel assessment system.
RESULTS
Mesonotum dipping with a 10⁸ conidia ml^-1 suspension and body contact with conidial suspension in sucrose solution caused high mortalities of adult forager bees at 25 °C optimal for conidial germination and hyphal invasion. Intriguingly, colony sizes in the hives contaminated by the forager bees contacting viable and inactivated conidia at two sites (1.2 km in distance), respectively, showed similar increase percentages (31.7% versus 29.2%) during a 4-week summer period of exposure to environment. No sign of fungal infection was found within each of the monitored colonies. Neither was fungal outgrowth observed on surfaces of bee cadavers cleaned from each hive at either site. Hourly counts of cleaned cadavers from videotapes presented no significant difference in colony-cleaning behavior between the two sites. During the period, in-hive temperatures at both sites were persistently stabilized at approximately 35 °C, which abolished conidial germination and were far above the out-hive temperature range.
CONCLUSION
It is colony heating that protects honey bee populations from a risk of forager bees' contact with formulated conidia applied for arthropod pest control. No role was detected for colony self-cleaning behavior in protecting the bee colonies from the risk.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Yuxian Xia

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
non-target effects/fate in environm.
application technology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
Beauveria bassiana (entomopathogen)