Pollinator nutrition is a highly complex subject that we are just starting to unravel, from the multidimensional nature of bee forage (pollen and nectar) to how the abiotic environment can affect the resources available to bees. Doing so is of utmost importance, as improving pollinator resource availability and nutrition is one of the proposed mechanisms to improve populations and pollinator health. However, landscape change has changed the resources naturally available for pollinators. Farmland and cropping systems create a unique nutritional landscape for pollinators, with agroecosystems typically containing few crops dominating a landscape along with natural corridors containing noncrop plants. The types of crops planted and the surrounding landscape will ultimately affect the nutritional landscape bees have access to. Even the management practices in agriculture and how pests are controlled will, directly and indirectly, affect bee health and nutrition. Hence, a better understanding of bee nutrition in agricultural ecosystems is warranted. This review synthesizes research on bee nutritional ecology and the agricultural landscapes to advance our understanding of bee health in agriculture.
3 February 2021 in Annals of the Entomological Society of America
The diversity and abundance of native bees (Hymenoptera: Anthophila) are important in providing pollination services to a diverse array of crops. An extensive literature base is available on the contributions of bees as crop pollinators. The focus of the majority of these studies are on honey bees (Apis spp.) pollinating crops that depend on cross-pollination to produce a yield. Self-pollinating crop species, including cotton, soybeans, coffee, and canola, can self-pollinate but there is increasing evidence that they can also benefit from cross-pollination by insects. These crops can see a considerable benefit when visited by bees in general, but contradictory evidence is not fully understood in some systems. For example, recent studies have shown that bee visitation to cotton blooms can increase yield up to 15%. Including nesting habitat for non-Apis bees within soybean dominated landscapes increases in-field yields. However, in these same systems, some studies show none or minimal yield increases. Additional literature (both recent and historical) of non-Apis bees in mass-flowering self-pollinating crops and their potential benefits to the crops also exists but is previously unsynthesized in cotton and soybeans in particular. In our review of literature on these select self-pollinating crops, there appears to be apparent gaps in the literature base on these and other understudied cropping systems. With the exception of graminaceous and cereal crops, all the crops discussed herein seem to have all have benefited from visitation by both Apis and non-Apis bees. Some provide known resource benefits to native bee pollinators like canola, but others like cotton and soybean are not well understood. Further, with an apparent yet small literature base in cotton and soybean there are many facets between the native bee pollinators and crop such as nutritional benefits of nectar and pollen to the bees themselves that still need to be addressed. To examine these underlying mechanisms, additional studies into the basic biology and natural history, including nesting habitats and preferences along with foraging preferences of abundant bee species will help understand how these bees seem to persist and possibly thrive in intensified agricultural systems.
Native bees (Hymenoptera: Anthophila) were sampled using bee bowls in two states to determine biodiversity in commercial cotton fields of the southern United States. In both states, native bee communities found in cotton fields were dominated by generalist pollinators in the genera Agapostemon, Augochloropsis, Halictus, and Lasioglossum (Hymenoptera: Halictidae), and Melissodes (Hymenoptera: Apidae). Melissodes tepaneca (Cresson) was the most abundant species found in cotton fields in both states. Some species collected are known specialists on other plant taxa, suggesting they may be tourist species. Here we provide a baseline species list of native bees found in cotton. Ordination indicated separation between the communities found in the two states when pooled by genus, but these differences were not significant. While cotton is grown in highly managed and disturbed landscapes, our data suggest that a community of common generalist native pollinators persists. Many of these species are also found in other cropping systems across North America.
The two-spot cotton leafhopper, Amrasca biguttula (Ishida, 1913) (Hemiptera: Cicadellidae), is a polyphagous pest native to the Indian subcontinent, where it is a significant pest of cotton (Gossypium spp.), okra (Abelmoschus esculentus, Moench), and other crops. At adult and immature stages, they feed on leaf cell contents, causing characteristic “hopperburn” symptoms and yield losses of up to 40% in cotton in its native range. In July 2025, A. biguttula was detected for the first time during the cotton growing season in commercial and experimental fields across multiple counties in Alabama, Florida, Georgia, and South Carolina. Identification was confirmed through morphological examination of diagnostic external features and male genitalia. Within four weeks, the pest was found in 101 counties, with injury symptoms ranging from mild chlorosis to severe necrosis and defoliation. Given the southeastern United States’ average of 979,339 hectares of cotton valued at USD 1.7–USD 2.8 billion annually, the potential for economic impact is considerable. Rapid symptom development, broad host range, and multiple generations per year underscore the need for coordinated monitoring and research to determine preliminary control measures and to identify potential alternative hosts. This report documents the first confirmed occurrence of A. biguttula in U.S. cotton and highlights its potential as an established recurring pest threat in the region.
The cotton agroecosystem is one of the most intensely managed, economically and culturally important cropping systems worldwide. Native pollinators are essential in providing pollination services to a diverse array of crops, including those which have the ability to self-pollinate. Cotton, which is autogamous, can potentially benefit from insect-mediated pollination services provided by native bees within the agroecosystem. Examined through two replicated experiments over two years, we hypothesized that native bees facilitated cross-pollination, which resulted in increased lint of harvested bolls produced by flowers exposed to bees and overall lint weight yield of the plant. Cotton bolls from flowers that were caged and exposed to bees, flowers that were hand-crossed, and bolls from flowers on uncaged plants exposed to pollinators had higher pre-gin weights and post-gin weights than bolls from flowers of caged plants excluded from pollinators. When cotton plants were caged with the local native bee Melissodes tepaneca, seed cotton weight was 0.8 g higher on average in 2018 and 1.18 g higher on average in 2019 than when cotton plants were excluded from bees. Cotton production gains from flowers exposed to M. tepaneca were similar when measuring lint and seed separately. Cotton flowers exposed over two weeks around the middle of the blooming period resulted in an overall yield gain of 12% to 15% on a whole plant basis and up to 24% from bolls produced from flowers exposed directly to M. tepaneca. This information complements cotton-mediated conservation benefits provided to native pollinators by substantiating native bee-mediated pollination services provided to the cotton agroecosystem.