Honey bee colony loss linked to parasites, pesticides and extreme weather across the United States

Abstract

Honey bee (Apis mellifera) colony loss is a widespread phenomenon with important economic and biological implications, whose drivers are still an open matter of investigation. We contribute to this line of research through a large-scale, multi-variable study combining multiple publicly accessible data sources. Specifically, we analyzed quarterly data covering the contiguous United States for the years 2015-2021, and combined open data on honey bee colony status and stressors, weather data, and land use. The different spatio-temporal resolutions of these data are addressed through an up-scaling approach that generates additional statistical features which capture more complex distributional characteristics and significantly improve modeling performance. Treating this expanded feature set with state-of-the-art feature selection methods, we obtained findings that, nation-wide, are in line with the current knowledge on the aggravating roles of Varroa destructor and pesticides in colony loss. Moreover, we found that extreme temperature and precipitation events, even when controlling for other factors, significantly impact colony loss. Overall, our results reveal the complexity of biotic and abiotic factors affecting managed honey bee colonies across the United States.

Cold storage as part of a Varroa management strategy: Effects on honey bee colony performance, mite levels and stress biomarkers

“…A second possibility is that the Varroa levels prior to storage were too high for successful treatment in this manner, despite miticide application prior to storage. Comparatively high Varroa densities are common in the southwestern US 4 . In this case 26% of the colonies in the rst year and 29% of the colonies in the second year had Varroa densities in excess of 3 mites per 100 bees, which has been considered a threshold for late summer/early fall application 21 .…”

“…The impact of Varroa on colony health is well known 1,2 , and reducing Varroa infestations is a primary goal and major expense for beekeepers 3 . Managing Varroa in warmer areas in the western US is particularly challenging because colonies forage and produce more brood during winter months, and thus can facilitate Varroa population growth over a longer period, than those in other regions 4 . Varroa mites in brood cells are largely protected from many miticides, so the more brood there is during application, the larger the protected population of mites.…”

Different effects of pesticides on transcripts of the endocrine regulation and energy metabolism in honeybee foragers from different colonies

“…The reasons for bee mortality are many and varied, including habitat loss 5 , parasites and diseases 9 , 10 extreme weather 11 and the exposure to pesticides 12 . Pesticides are biological agents or synthesized substances used for killing or restricting the development of organisms 13 .…”

First large-scale study reveals important losses of honey bee and stingless bee colonies in Latin America

“…These successful large-scale monitoring programs have in common the establishment of standardized questionnaires and the centralization of data collection and analysis [22] . These large-scale monitoring initiatives contributed substantially to identifying risk factors such as ower resource availability [23][24][25][26] , beekeeping management [14,16,[26][27][28] and climate [29][30][31][32] . However, our current knowledge of the extent and causes of bee colony losses is mostly based on published studies carried out in the Northern Hemisphere, in particular, in the United States and Europe (but see smaller-scale studies from other regions like China [33,34] , South Africa [35] , Japan [36] , Canada [37] , and some Latin American countries [38][39][40][41] ), whereas several countries from the Southern Hemisphere play critical roles as suppliers to the global honey market and in bee-driven crop pollination services [39] .…”