Robert P. Jean

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 >

Effectiveness of Bowl Trapping and Netting for Inventory of a Bee Community

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 difficult to quantify the status of bee communities or estimate the extent of declines. We used data from 11 multiyear studies of bee communities to devise a program to monitor pollinators at regional, national, or international scales. In these studies, 7 different methods for sampling bees were used and bees were sampled on 3 different continents. We estimated that a monitoring program with 200-250 sampling locations each sampled twice over 5 years would provide sufficient power to detect small (2-5%) annual declines in the number of species and in total abundance and would cost U.S.

Documenting Persistence of Most Eastern North American Bee Species (Hymenoptera: Apoidea: Anthophila) to 1990–2009

2,000,000. To detect declines as small as 1% annually over the same period would require >300 sampling locations. Given the role of pollinators in food security and ecosystem function, we recommend establishment of integrated regional and international monitoring programs to detect changes in pollinator communities.

A Survey of Bees (Hymenoptera: Apoidea) of the Indiana Dunes and Northwest Indiana, USA

ABSTRACT Concern over the status of bees has increased the need to inventory bee communities and, consequently, has increased the need to understand effectiveness of different bee sampling methods. We sampled bees using bowl traps and netting at 25 northwest Indiana sites ranging from open grasslands to forests. Assemblages of bees captured in bowl traps and by netting were very similar, but this similarity was driven by similar relative abundances of commonly captured species. Less common species were often not shared between collection methods (bowls, netting) and only about half of the species were shared between methods. About one-quarter of species were more often captured by one of the two collection methods. Rapid accumulation of species was aided by sampling at temporal and habitat extremes. In particular, collecting samples early and late in the adult flight season and in open and forest habitats was effective in capturing the most species with the fewest samples. The number of samples estimated necessary to achieve a complete inventory using bowls and netting together was high. For example, ≈72% of species estimated capturable in bowls were captured among the 3,159 bees collected in bowls in this study, but ≈30,000–35,000 additional bees would need to be collected to achieve a 100% complete inventory. For bowl trapping, increasing the number of sampling dates or sampling sites was more effective than adding more bowls per sampling date in completing the inventory with the fewest specimens collected.

Evidence-based conservation: reply to Tepedino et al.

Abstract The status of wild bees, the major group of pollinators in most biomes, has gained recognition as an important ecological and economic issue. Insufficient baseline data and taxonomic expertise for this understudied group has hindered efforts to assess the conservation status of the majority of wild bee species. To more objectively address their current conservation status, we drew upon museum collections and the expertise of melittologists (biologists studying non-Apis bees) to compile a complete list of bee species for eastern North America, discriminating those which have and have not been detected during the past 20 years. The vast majority (95% of about 770 eastern North American bee species) have been found again, at least once since 1990. The remaining 37 species were rarely collected before 1990 as well. Some may truly be at risk (or lost). Others are undoubtedly data deficient due to inadequate knowledge of their biology or hosts, or the geographic regions and local habitats where they occur. Distributional and ecological patterns among these missing species are discussed. Most were recorded in the region only from peripheral areas or areas known to be undersampled by recent collectors, such as the southeastern United States. Others are characterized by specialized life histories or they cannot be identified routinely in the absence of taxonomic revisions. Clearly, most eastern North American bee species have persisted until recent times, with no evidence of widespread recent extinctions. An absence of well-documented global extinctions of bee species does not warrant complacency regarding pollinator conservation, as our qualitative method does not lend itself to documenting range contractions, range fragmentation, or declines in abundance and species richness in local bee communities.

The Bee Fauna of Inland Sand Dune and Ridge Woodland Communities in Worcester County, Maryland

Abstract The Indiana Dunes, and nearby natural areas in northwest Indiana, are floristically rich Midwest U.S. locales with many habitat types. We surveyed bees along a habitat gradient ranging from grasslands to forests in these locales, collecting at least 175 bee species along this gradient plus 29 additional species in other nearby habitats. About 25% of all species were from the genus Lasioglossum and 12% of the species were associated with sandy soils. Several bumblebee (Bombus) species of conservation concern that should occur in this region were not collected during our surveys. Similarity of the northwest Indiana bee fauna to other published U.S. faunas decreased about 1.3% per 100 km distance from northwest Indiana. Thirty percent of bees netted from flowers were males. Males and females differed significantly in their frequency of occurrence on different plant species. For bees collected in bowl traps, the percentage captured in fluorescent yellow traps declined and in fluorescent blue traps increased from spring to late summer. Capture rates for different bee genera varied temporally, with about a quarter of the genera being captured most frequently in late spring and a quarter in late summer. Capture rates for most genera were higher in more open than in more closed canopy habitats. The maximum number of plant species on which a single bee species was captured plateaued at 24, on average. Forty-nine percent of bee species known to occur in Indiana were found at these northwest Indiana sites. Having this relatively high proportion of the total Indiana bee fauna is consistent with Indiana Dunes existing at a biogeographic crossroads where grassland and forest biomes meet in a landscape whose climate and soils are affected by proximity to Lake Michigan. The resulting habitat, plant, edaphic, and climatic diversity likely produces the diverse bee community documented.

Floral and nesting resources, habitat structure, and fire influence bee distribution across an open‐forest gradient

Gretchen Lebuhn,∗ ¶ Sam Droege,† Edward F. Connor,∗ Barbara Gemmill-Herren,‡ Simon G. Potts,§ Robert L. Minckley,∗∗ Robert P. Jean,†† Emanuel Kula,‡‡ David W. Roubik,§§ Karen W. Wright,∗∗∗ Gordon Frankie,††† and Frank Parker‡‡‡ ∗Department of Biology, San Francisco State University, San Francisco, CA 94132, U.S.A. †USGS Patuxent Wildlife Research Center, 12100 Beech Forest Road, Laurel, MD 20708-4039, U.S.A. ‡Food and Agriculture Organization of the United Nations, viale delle Terme di Caracalla, Rome 00100, Italy §Centre for Agri-Environmental Research (CAER), School of Agriculture, Policy and Development, University of Reading, RG6 6AR, United Kingdom ∗∗Department of Biology, University of Rochester, Rochester, NY 14627, U.S.A. ††Department of Sciences and Mathematics, Saint Mary-of-the-Woods College, St. Mary of the Woods, IN 47876, U.S.A. ‡‡Faculty of Forestry and Wood Technology, Mendel University of Agriculture and Forestry, Zemědělska 3 CZ-61300 Brno 420 545 134 127, Czech Republic §§Smithsonian Tropical Research Institute, Box 0843–03092 Balboa Ancon, Republic of Panama ∗∗∗Sevilleta LTER, Department of Biology 167 Castetter Hall, MSC03 20201, University of New Mexico, Albuquerque, NM 87131-0001, U.S.A. †††Dept of Environmental Science, Policy, & Management, University of California, Berkeley, CA 94720, U.S.A. ‡‡‡USDA-ARS Bee Biology and Systematics Lab, Utah State University, Logan, UT 84322, U.S.A.

Quantifying a Rare Event: Pollen Theft by Honey Bees from Bumble Bees and Other Bees (Apoidea: Apidae, Megachilidae) Foraging at Flowers

Abstract We surveyed bees inhabiting inland dune and ridge woodlands at 30 sites in Worcester County, MD, in 2008 and 2009 . We collected and identified 4878 bees representing 5 families, 31 genera, and 121 species. Here, we report data on annual and seasonal variation. Expanding survey efforts to include multiple years and seasons served to increase the overall number of species encountered, primarily through documenting the presence of rare or infrequently collected species. Eighty-eight species (73%) were represented by fewer than 10 individuals; of these 30 were represented by a single individual (25% of the total). The 5 most dominant species represented nearly half (48%) of the total number of specimens. We report a list of bee species collected from inland dune and ridge woodlands and discuss the presence of apparently habitat-restricted species.