Skip to main content
U.S. flag

An official website of the United States government


Exotic plant infestation is associated with decreased modularity and increased numbers of connectors in mixed-grass prairie pollination networks

The majority of pollinating insects are generalists whose lifetimes overlap flowering periods of many potentially suitable plant species. Such generality is instrumental in allowing exotic plant species to invade pollination networks. The particulars of how existing networks change in response to an invasive plant over the course of its phenology are not well characterized, but may shed light on t
Diane L. Larson, Paul A. Rabie, Sam Droege, Jennifer L. Larson, Milton Haar

Bees: An up-close look at pollinators around the world

While we eat, work, and sleep, bees are busy around the world. More than 20,000 species are in constant motion! They pollinate plants of all types and keep our natural world intact. In Bees, you'll find a new way to appreciate these tiny wonders. Sam Droege and Laurence Packer present more than 100 of the most eye-catching bees from around the world as you've never seen them: up-close and with stu
Sam Droege, Laurence Packer

Pollinators in peril? A multipark approach to evaluating bee communities in habitats vulnerable to effects from climate change

In 2010, collaborators from the National Park Service (Ann Rodman, Yellowstone National Park), USGS (Sam Droege and Ralph Grundel), and Harvard University (Jessica Rykken) were awarded funding from the NPS Climate Change Response Program to launch just such an investigation in almost 50 units of the National Park System (fig. 1). The main objectives of this multiyear project were to: Compare bee c
Jessica Rykken, Ann Rodman, Sam Droege, Ralph Grundel

Using a network modularity analysis to inform management of a rare endemic plant in the northern Great Plains, USA

1. Analyses of flower-visitor interaction networks allow application of community-level information to conservation problems, but management recommendations that ensue from such analyses are not well characterized. Results of modularity analyses, which detect groups of species (modules) that interact more with each other than with species outside their module, may be particularly applicable to ma
Diane L. Larson, Sam Droege, Paul A. Rabie, Jennifer L. Larson, Jelle Devalez, Milton Haar, Margaret McDermott-Kubeczko

Detecting insect pollinator declines on regional and global scales

Recently there has been considerable concern about declines in bee communities in agricultural and natural habitats. The value of pollination to agriculture, provided primarily by bees, is >$200 billion/year worldwide, and in natural ecosystems it is thought to be even greater. However, no monitoring program exists to accurately detect declines in abundance of insect pollinators; thus, it is diffi
Gretchen Lubuhn, Sam Droege, Edward F. Connor, Barbara Gemmill-Herren, Simon G. Potts, Robert L. Minckley, Terry Griswold, Robert Jean, Emanuel Kula, David W. Roubik, Jim Cane, Karen W. Wright, Gordon Frankie, Frank Parker

New synonymies in the bee genus Nomada from North America (Hymenoptera: Apidae)

We provide diagnostic morphological characters to help distinguish males and females of the following species of Nomada: N. augustiana Mitchell, N. bethunei Cockerell, N. fervida Smith, N. fragariae Mitchell, N. lehighensis Cockerell, N. texana Cresson, and N. tiftonensis Cockerell. Based on morphological and DNA barcoding evidence we newly synonymize the following species: N. heligbrodtii Cresson
Sam Droege, M.G. Rightmyer, C.S. Sheffield, S.G. Brady

Spatial patterns of bee captures in North American bowl trapping surveys

1. Bowl and pan traps are now commonly used to capture bees (Hymenoptera: Apiformes) for research and surveys. 2. Studies of how arrangement and spacing of bowl traps affect captures of bees are needed to increase the efficiency of this capture technique. 3. We present results from seven studies of bowl traps placed in trapping webs, grids, and transects in four North American ecoregions (Mid-At
Sam Droege, Vincent J. Tepedino, Gretchen Lebuhn, William Link, Robert L. Minckley, Qian Chen, Casey Conrad

Evaluation of specimen preservatives for DNA analyses of bees

Large-scale insect collecting efforts that are facilitated by the use of pan traps result in large numbers of specimens being collected. Storage of these specimens can be problematic if space and equipment are limited. In this study, we investigated the effects of various preservatives (alcohol solutions and DMSO) on the amount and quality of DNA extracted from bees (specifically Halictidae, Api
M. Frampton, Sam Droege, T. Conrad, S. Prager, M.H. Richards