Biology subjects

Lamas, Z.

Publications and source records attributed to Lamas, Z..

3 recordsLinked to original sources

bioRxiv2025

Insights from U.S. beekeeper triage surveys following unusually high honey bee colony losses 2024-2025

In January of 2025, U.S. commercial beekeepers reported unusually high honey bee colony losses as they prepared colonies for almond pollination. Two industry groups launched nationwide surveys to document colony losses between June 2024 and March 2025 across all scales of beekeeping. This study analyzes these survey data to assess colony losses, estimate financial impacts, and identify correlations with beekeeper management practices and geographical locations. Unlike past surveys, commercial beekeepers experienced more severe losses than smaller-scale beekeepers during this period. Respondents, managing over half of U.S. colonies, most frequently cited Varroa mites as the cause for their losses. Varroa mites were followed by pesticides and pathogens in the case of commercial beekeepers and by queen failure and weather in the case of smaller-scale beekeepers. Although Varroa was the most frequently cited cause, losses did not significantly differ between users and non-users of amitraz, suggesting that rising amitraz resistance alone does not explain observed trends. Differences in protein and carbohydrate feeding frequencies also played a role in net losses. While colony loss rates and financial concern varied widely among respondents, commercial beekeepers understandably showed higher sensitivity to financial impacts, with concerns increasing linearly with loss severity. This study highlights the value of beekeeper surveys which, alongside direct analyses of bee samples and longitudinal studies, help identify effective management strategies and environmental risks. Such insights are crucial for addressing the leading causes of colony losses on a national scale, and ultimately aid in safeguarding honey bee health, pollination services, and agricultural production. HighlightsO_LIUnprecedented honey bee colony losses C_LIO_LIIndications of disease stress C_LIO_LIHigh economic pain for commercial beekeepers and growers C_LI

ecology↗

bioRxiv2025

Viruses and vectors tied to honey bee colony losses

Commercial beekeepers in the US reported severe colony losses early in 2025, as colonies were being staged for their critical role in the almond pollination season in California. Average reported losses since the preceding spring exceeded 60%, with substantial variation among operations. Many colonies were still actively collapsing in January, 2025, when pooled and individual samples were collected then screened for levels of known honey bee pathogens and parasites. Deformed wing virus strains A and B, along with Acute bee paralysis virus, were found at unusually high levels, either in pooled colony samples or in individual bees exhibiting shaking behaviors and morbidity. Differences between these two analyses suggest that direct collections of morbid bees provide a superior diagnostic for causal viruses, a suggestion borne out by confirmation of symptoms and morbidity following isolation and new inoculations. Since these viruses are known to be vectored by parasitic Varroa mites, mites from collapsed colonies were in turn screened for resistance to amitraz, a critical miticide used widely by beekeepers. Miticide resistance was found in all collected Varroa, underscoring the urgent need for new control strategies for this parasite. While viruses are a likely end-stage cause of colony death, other stressors such as nutritional stress and agrochemicals may have also played significant roles.

ecology↗

bioRxiv2025

Amitraz Toxicity in Resistant Varroa Mites Can Be Increased by Inhibiting ABCB1 Transporters

As critical pollinators of agricultural crops, honey bees (Apis mellifera) play a vital role in food production. Therefore, it is imperative to investigate and develop new methods to control Varroa destructor, a devastating parasitic mite of honey bee colonies that weakens bees and spreads deadly diseases that lead to colony loss. Here, we adapted existing methods to investigate the role of ABCB1 transporters in mitigating the toxicity of amitraz, a widely used miticide approved for use in honey bee colonies, demonstrating that a pharmacological inhibitor can synergistically increase amitraz toxicity compared to the equivalent dose of amitraz alone. Evaluations performed on the mites used in one of the described experiments revealed a high proportion of the test subject mites (88.5%) possessed the amitraz resistant genotype, indicating that even in resistant mites, inhibiting ABCB1 transporters can increase amitraz efficacy. This promising finding may be useful in developing powerful synergists that can be used to increase the efficacy of new and existent miticides.

pharmacology and toxicology↗