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Winter poses a challenge to the survival of honey bees

Winter poses a significant challenge to honey bee colonies in the United States, with beekeepers reporting a loss of one-third of their colonies during this season annually.

Research now indicates that employing multiple pest management strategies could enhance colony survival through harsh winter months.

Multiple defenses better than one

A team of researchers from Pennsylvania State University has discovered that beekeepers who apply various treatments for Varroa mites (a major parasitic threat) see higher winter survival rates in honey bee colonies compared to those using a single treatment method.

Varroa mites significantly weaken bees by spreading diseases. These mites attach to bees, feeding on their bodily fluids and transmitting harmful viruses. This process severely compromises the health of bees and can lead to the collapse of entire colonies.

The study highlights that weather conditions also play a crucial role in the survival of bee colonies during winter.

However, beekeepers utilizing integrated pest management approaches, which involve multiple strategies to tackle Varroa mites, tend to achieve better colony survival rates, even in adverse weather conditions.

Honey bee dynamics

“Understanding how beekeeping strategies and environmental factors affect honey bees is crucial, especially under the increasing variability of weather,” said Darcy Gray, the study’s lead researcher.

Gray emphasized that this knowledge is vital not only for maintaining honey bee populations, which are critical pollinators of various North American crops, but also for gaining insights into the challenges faced by native bee species, which are similarly threatened by habitat loss and climate change.

Christina Grozinger, who contributed to the study, noted the complexity of habitat and weather factors affecting bees. “To truly understand these impacts, extensive data is needed.”

Grozinger pointed out the enormous value of long-term data provided by Pennsylvania beekeepers through annual surveys, which include details about their management practices and the outcomes over the winter months.

Varied treatments yield better results

As discussed, the research revealed that beekeepers who actively treated their honey bee colonies for Varroa mites reported significantly higher survival rates than those who did not.

More interestingly, those employing a mix of treatment types – whether chemical or organic – saw better results than those relying on a single method.

The study also addressed the effectiveness of soft chemicals like naturally derived organic compounds versus hard chemicals, which are synthetic and can leave long-lasting residues in colonies.

Surprisingly, both types of chemicals were found to be equally effective in increasing winter survival, challenging the notion that harder chemicals might induce resistance among Varroa mites.

Winter and honey bee survival

The relationship between seasonal weather conditions and bee colony survival was another focal point of the study.

While spring, fall, and winter precipitation correlated with increased bee survival, summer rain appeared to negatively affect colonies.

“Prolonged rain during summer can diminish bees’ foraging time, leading to reduced food storage for winter and lower brood production,” explained Grozinger.

This dynamic highlights the critical role of weather on the flowering plants bees rely on for sustenance.

Integrating pest management for climate resilience

This research is not just about improving bee survival over the winter but also serves as a foundation for future studies.

Gray hopes that the insights gained will help beekeepers optimize their apiary management strategies and serve as a basis for additional research.

“Our findings suggest that integrated pest management could buffer honey bee colonies from the severe impacts of weather, which is vital for adapting beekeeping to climate change,” concluded Gray.

The outcomes of this research provide a clear message to beekeepers: diversifying pest management strategies is essential for enhancing honey bee resilience, particularly as environmental conditions grow more unpredictable.

Implementing multiple treatments for Varroa mites increases the chances of colony survival during winter. This approach addresses the complexity of challenges faced by bees, including disease transmission and adverse weather conditions.

By adopting integrated pest management, beekeepers can improve the health and longevity of their colonies. This strategy is crucial not only for the survival of honey bees but also for maintaining the broader ecosystem that relies on their pollination services.

The study is published in the Journal of Insect Science.


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