Do honey bee (Apis mellifera) foragers recruit their nestmates to native forbs in reconstructed prairie habitats?

Abstract

Honey bee (Apis mellifera) colonies are valued for the pollination services that they provide. However, colony mortality has increased to unsustainable levels in some countries, including the United States. Landscape conversion to monocrop agriculture likely plays a role in this increased mortality by decreasing the food sources available to honey bees. Many land owners and organizations in the Upper Midwest region of the United States would like to restore/reconstruct native prairie habitats. With increasing public awareness of high bee mortality, many landowners and beekeepers have wondered whether these restored prairies could significantly improve honey bee colony nutrition. Conveniently, honey bees have a unique communication signal called a waggle dance, which indicates the locations of the flower patches that foragers perceive as highly profitable food sources. We used these communication signals to answer two main questions: First, is there any part of the season in which the foraging force of a honey bee colony will devote a large proportion of its recruitment efforts (waggle dances) to flower patches within prairies? Second, will honey bee foragers advertise specific taxa of native prairie flowers as profitable pollen sources? We decoded 1528 waggle dances in colonies located near two large, reconstructed prairies. We also collected pollen loads from a subset of waggle-dancing bees, which we then analyzed to determine the flower taxon advertised. Most dances advertised flower patches outside of reconstructed prairies, but the proportion of dances advertising nectar sources within prairies increased significantly in the late summer/fall at one site. Honey bees advertised seven native prairie taxa as profitable pollen sources, although the three most commonly advertised pollen taxa were non-native. Our results suggest that including certain native prairie flower taxa in reconstructed prairies may increase the chances that colonies will use those prairies as major food sources during the period of greatest colony growth and honey production.

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

“…Alternatively, studies investigating agricultural landscapes that incorporate diversity through the addition of hedgerows and/or buffer strips of seminatural or native habitat have shown the potential to increase wild bee abundance and richness ( Morandin and Kremen 2013 , Schulte et al 2017 , Sutter et al 2017 ). In the region of this study, native plantings in the form of prairie have been shown to provide valuable resources for honey bees in the late season ( Carr-Markell et al 2020 ), to sustain colony growth, and to enhance individual honey bee lipid levels ( Dolezal et al 2019a ). We suggest an increase in more native, perennial habitat may be a better option to support both wild and managed bee pollinators in extensive agricultural systems.…”

“…From those farms, we randomly selected a subset of farms which did not have honey bee colonies placed within 1.6 km, and all sites were located at least 3.2 km or more from one another. We chose this distance to reduce resource competition with our sentinel colonies (see below), as studies indicate that on average, foragers do not often forage farther than 2 km from their hives ( Couvillon et al 2014 , Seeley 2019 , Carr-Markell et al 2020 ). In total, 4 Div-FV and 10 Mono-SOY farms were selected in 2015 and 5 Div-FV and 10 Mono-SOY farms in 2016 ( Supp Table 1 [online only] ).…”

Honey robbing: could human changes to the environment transform a rare foraging tactic into a maladaptive behavior?

“…Crop bloom results in boom-and-bust periods of resource availability, and honey bee colony health strongly tracks these feast-famine cycles [2]. In the U.S.A., a general period of nectar dearth arises in the mid-late summer, in part from the loss of native flowering prairie lands that naturally bloom at this time [3]. The replacement of natural floral communities with crop and grazing lands can increase competition for food among bee species, or alternatively, decrease competition by eliminating natural refuges and wild bees altogether [4].…”

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

“…The placement of a pan trap can affect how many pollinators are captured [ 5 ]. Unlike many wild bees, which forage 500 m or less from their nest location [ 74 , 75 ], honey bees are capable of longer foraging distances (>10 km) [ 76 ], and in agricultural landscapes commonly forage within 2 km of their colony [ 30 , 31 , 32 ]. As a result, it is necessary to place pan traps at multiple positions and distances from the colonies in order to best estimate how pan trap placement and honey bee activity-density are related.…”

“…Quantifying honey bee activity within a crop field can help determine the relationship between the stocking rates of crops requiring pollination [ 19 , 28 , 29 ]. Current methods, such as observing honey bee waggle dances [ 30 , 31 , 32 ], radio frequency ID tagging [ 33 , 34 ], and direct observations of honey bee foraging [ 35 , 36 ] are limited in scope, time consuming, laborious, and can require highly specialized skills. Pan traps could be an efficient alternative, but it is unclear how well they estimate honey bee activity-density.…”