Diversified Farming in a Monoculture Landscape: Effects on Honey Bee Health and Wild Bee Communities

Abstract

In the last century, a global transformation of Earth’s surface has occurred due to human activity with extensive agriculture replacing natural ecosystems. Concomitant declines in wild and managed bees are occurring, largely due to a lack of floral resources and inadequate nutrition, caused by conversion to monoculture-based farming. Diversified fruit and vegetable farms may provide an enhanced variety of resources through crops and weedy plants, which have potential to sustain human and bee nutrition. We hypothesized fruit and vegetable farms can enhance honey bee (Hymenoptera: Apidae, Apis mellifera Linnaeus) colony growth and nutritional state over a soybean monoculture, as well as support a more diverse wild bee community. We tracked honey bee colony growth, nutritional state, and wild bee abundance, richness, and diversity in both farm types. Honey bees kept at diversified farms had increased colony weight and preoverwintering nutritional state. Regardless of colony location, precipitous declines in colony weight occurred during autumn and thus colonies were not completely buffered from the stressors of living in a matrix dominated with monocultures. Contrary to our hypothesis, wild bee diversity was greater in soybean, specifically in August, a time when fields are in bloom. These differences were largely driven by four common bee species that performed well in soybean. Overall, these results suggest fruit and vegetable farms provide some benefits for honey bees; however, they do not benefit wild bee communities. Thus, incorporation of natural habitat, rather than diversified farming, in these landscapes, may be a better choice for wild bee conservation efforts.

Pan Traps for Tracking Honey Bee Activity-Density: A Case Study in Soybeans

“…The use of all three-trap colors throughout our study may have contributed to the low estimates of abundance of honey bees based on a per trap per site measurement. For honey bees captured in blue bowls, our collections of 1.5 honey bees per trap per site are consistent with collections of other common bee species captured in pan traps in this region [ 42 , 43 , 44 , 72 , 73 ].…”

Distribution of wild bee (Hymenoptera: Anthophila) and hoverfly (Diptera: Syrphidae) communities within farms undergoing ecological transition

“…Pollinator composition of each farmstead harboured both common and rare species, which indicates that on-farm diversification and organic practices may be an important refuge for rare, Red-Listed or oligolectic pollinator species ( Guzman et al 2019 ). Restoring or incorporating diverse habitats in agro-ecosystems is therefore a long-term solution for the conservation of pollinating species ( Saint Clair et al 2020 ).…”

A honey bee symbiont buffers larvae against nutritional stress through lysine supplementation

“…These declines are often credited to a combination of stressors, the crux of which is poor nutrition (3)(4)(5). Poor nutrition for managed honey bee colonies is partly due to dwindling natural floral resources and an increase in reliance on large monoculture crops (33,34). These large monocultures pose especially difficult nutritional landscapes for honey bees, as pollen from most individual crops only barely provides a colony's base nutritional requirements (35,36).…”