2010 MV Native Bee Summary - The Trustees of Reservations

Inventory of Martha’s Vineyard’s Native Bees for Conservation, Monitoring, and Management March, 2011 Paul Z. Goldstein, PhD Smithsonian Institution P.O. Box 37012 National Museum of Natural History, E-­‐523, MRC 168 Washington, DC 20013-­‐7012 Russell Hopping Ecology Program Manager The Trustees of Reservations The Stevens-­‐Coolidge Place 113 Andover Street N. Andover, MA 01845 1 SUMMARY We conducted the first inventory of native bees on Martha’s Vineyard. In partnership with the American Museum of Natural History (AMNH, New York), products include a sizeable reference collection of bees and other pollinating insects housed at the museum, a reference collection of native bees housed at The Trustees of Reservations regional office in Vineyard Haven (along with a growing reference collection of other Island insects), and a growing online resource comprising over 3,000 geo-­‐referenced records of Vineyard bees. As of 15 March 2011, the 2010 effort has documented 130 species of bees from Martha’s Vineyard. These make up approximately 40% of the 335 species recorded from Massachusetts, 27 of 38 of the recorded genera, and 41 of 74 subgenera known from the Commonwealth (Ascher et al., unpubl.). The rusty patched bumblebee Bombus affinis, a target species recorded from the island historically but not in 2010, is suspected of having been extirpated from the region. Additional inventory will be needed to confirm its disappearance from Martha’s Vineyard. By way of comparison to other recent work on Penikese and Cuttyhunk Islands (Stage, 2009) and on Gardiner’s Island, NY (Ascher et al., unpubl.), the 2010 Vineyard sample includes 27 species recorded from none of these islands. Twenty-­‐one of these were not recorded from Penikese and Cuttyhunk, from which there were 19 species that were not taken on the Vineyard (corresponding to a roughly symmetrical 87% overlap). In partnership with the Massachusetts Audubon Society at Felix Neck, we developed a volunteer base that remains active. Two formal programs were conducted on 24 June and 14 July at Felix Neck and Long Point, respectively. From over 40 attendees in total, an active emailing list includes over 30 participants, to whom various materials and web-­‐based educational resources were disseminated throughout the season. Over seven volunteers contributed directly to the sampling effort by deploying and retrieving 25 trap lines (>500 bee cups) at over 10 sites in Aquinnah, Chilmark, Edgartown, and Tisbury, and remain interested in continuing their participation in 2011 efforts. PROCEDURES/USE OF TIME Over 300 field-­‐hours were devoted to sampling bees, including the deployment and retrieval of >145 lines of 25-­‐30 “bee bowls” (~4,000 cups in toto) at over 50 sites and sub-­‐sites across the Island (Figure 1; Table 1, below). Both during the course of setting and retrieving these traps and during independent forays, bees were collected directly by net at flowers and at nesting sites on bare ground. However, the majority of this project’s time—over 1000 hours—was devoted to the preparation, labeling, and determination of approximately 10,000 specimens that resulted from the sampling effort. Dry specimens that were collected directly (by net) were pinned immediately (within 24 hours), but samples resulting from trap-­‐collecting were stored in 70% ethanol at 40°F until they could be prepared. The procedure for preparing fluid-­‐preserved specimens is much more involved than for dry specimens, and involves first sorting the bees from the other trapped insect “by-­‐catch”, mechanical rinsing with the aid of a magnetic stirring plate, and hot air batch-­‐drying in a screened mason jar before pinning and affixing of archive-­‐
quality labels, sorting and identification. Specimens are individually labeled with collecting data that includes locality, latitude, longitude, date and means of collection. Although most of the material was prepared, approximately 2,000 specimens tentatively identified as among the more common species during a preliminary “triage” were left stored in vials to save time and expense associated with pinning. A serious effort was made to ensure that representatives of all species were prepared and minimize the risk of any left behind in the triaged material. FINDINGS The work documents both a diverse component of the Vineyard’s native pollinator fauna and in particular an apparently diverse bee fauna likely to include many more species than verified so far. The 130 species documented thus far include not only polylectic social bees, but also social parasite and cleptoparasitic (“cuckoo”) 2 bees, habitat-­‐ and hostplant-­‐specialist pollinators such as the blueberry obligate mason bee Osmia virga, and regionally rare species (e.g. Andrena ceanothi, Anthidiellum notatum, Bombus sandersoni, Hylaeus schwarzii). Some of these are of imminent conservation concern, most notably the digger bee Anthophora walshii, which until its discovery in Manuel Correllus State Forest on 3 August 2010 had been unrecorded from the Northeast since the 1970s. Figure 1: Partial distribution of collecting sites on Martha’s Vineyard in 2010. This map was generated from the bee database and includes only those sites from which bees have been databased thus far. It does not all the sites visited or trapped.
3 Table 1. Bee trap-­‐lines deployed from April-­‐September 2010 on Martha’s Vineyard, presented by town. Numbers indicate frequency within a given week. Abbreviations/Acronyms: MAS = Massachusetts Audubon Society; MVLB = Martha’s Vineyard Land Bank; TNC = The Nature Conservancy; TTOR = The Trustees of Reservations; VCS = Vineyard Conservation Society; MCSF = Manuel F. Correllus State Forest. This table illustrates only the coverage as reflected in the trapping schedule, and does not reflect individual, ad hoc hand-­‐netting efforts by Goldstein. Some of the more cryptic species are either undescribed, as in the case of at least one cuckoo bee (Nomada sp.), or described only recently, such as the sweat bee Lasioglossum timothyi Gibbs, 2010. The findings also included various pairs of species and their specialist parasites (e.g. plasterer bees, Colletes spp. and at least three species of associated cuckoo bees, Epeolus spp.; Bombus citrinus, a social parasite of B. impatiens, etc.). Although several species of bees—especially certain sweat bees—are demonstrably hyper-­‐abundant on the Vineyard (e.g. Augochlorella aurata, Halictus ligatus, Lasioglossum leucozonium, Lasioglossum oceanicum, Agapostemon s pp.), some species are decidedly rare in our samples. Both Anthidiellum notatum and Anthophora walshii appeared as singletons in more than 10,000 specimens sampled and various Epeolus, Triepeolus, Melissodes and Bombus were found in extremely low numbers (<10). This illustrates perhaps more than species-­‐to-­‐species variation in the effectiveness of paint bowl traps—possibly genuine scarcity of the species in question—but most important the necessity of intensive sampling. 4 Table 2. Number of bee species, by genus, recorded from Martha’s Vineyard in 2010 versus known Massachusetts records. “H” refers to historical records of Bombus affinis from Long Point (1987) and Gay Head (1993). PRODUCTS All our bee specimens are deposited either at AMNH or on-­‐Island at the Regional Office of The Trustees of Reservations as a developing reference collection to be for future scientific, educational, and monitoring programs. In the original proposal to the Edey Foundation, we alluded to the hopeful possibility that our data would one day be databased online using the AMNH system developed specifically for accommodating and visualizing geo-­‐
referenced specimen data (see Schuh et al., 2010). Although we did not request funds to cover data entry, this work has proceeded more quickly than anticipated thanks to contributions of time by Dr. John Ascher and Mr. Eli Wyman at the AMNH and Ms. Cerina Gordon of West Tisbury. As of 21 March 2011, 3,068 specimens have been databased, representing the core of the species and locality diversity. The databasing procedure involves affixing an additional, uniquely numbered label with a digitally readable matrix barcode to each specimen and entering all the associated data into the AMNH global bee database. From there it is uploaded every 24 hours to the Discover Life in America (DLIA) website (www.discoverlife.org) where it can be visualized geographically by anyone online, thus maximizing the data’s value and availability. The database itself can also be queried, such that a report can be generated detailing, for example, all the species known from Dukes County, or from West Tisbury, for example, or for all the locations where a given species or group of species occurs, etc. DIRECTIONS FOR FUTURE WORK Following a systematic comparison of our bee fauna with known occurrences elsewhere in the Northeast, including Penikese, Cuttyhunk, Gardiner’s Island, NY and the rest of Massachusetts (Stage, 2009; Ascher et al., unpubl.) as well as historical records from Nantucket recently re-­‐examined by P. Goldstein and S. Kent, we have a reasonable 5 understanding of which components of the bee fauna are under-­‐represented in our samples, either because their host plants were not targeted aggressively enough or because their narrow activity periods fell unusually early in 2010. In order to better develop our understanding of the native pollinator fauna, we need first to target flowers with known assemblages of specialized groups of bees (e.g. Spring-­‐active andrenids) likely to be more species-­‐rich on-­‐island than documented so far. We have begun to analyze the composition of host associations and life histories of our native bees (e.g. whether they are social, solitary, parasitic, specialists versus generalists, etc.) and once the fauna is more completely characterized, we can not only identify gaps in our bee fauna, but also hope to determine whether they can be attributed to historical ecological factors such as the natural absence of certain flowers or to recent anthropogenic ones such as the introduction of infected greenhouse bees. An understanding of the “core diversity” of native pollinators also now enables us to make management recommendations and suggest best practices for managed lands and native floral diversity, surrounding for example the planting of bee flowers and the timing of large-­‐ and small-­‐scale mowing. Towards the greater goal of understanding our island pollinator fauna more broadly, we anticipate processing and identifying the by-­‐catch from the 2010 bee-­‐trapping efforts, specifically the pollinating flies. There have been very few studies in which seasonal data for different groups of pollinators could be linked in this way, and we anticipate a number of peer-­‐reviewed publications based on these data in the years to come. ACKNOWLEDGMENTS We gratefully thank the following individuals and organizations for access to properties in their care: Suzan Bellincampi (Felix Neck Wildlife Sanctuary, Massachusetts Audubon Society), Tim Boland and Tom Clark (Polly Hill Arboretum), Brendan O’Neill (Vineyard Conservation Society), Matt Pelikan and Elizabeth Loucks (The Nature Conservancy), Julie Schaeffer (Martha’s Vineyard Land Bank), John Varkonda (Manuel F. Correllus State Forest, Massachusetts Department of Conservation and Recreation), Albert O. Fisher, Charlie Pachico (Seven Gates Farm), Caitlin Jones (Mermaid Farm), Andrew Woodruff (Whippoorwill Farm). Soo Whiting, Tara Whiting, and Tom Hodgson enabled access to Quansoo and Black Point. For contributing to the sampling effort, we thank in particular Tom Hodgson, Laurisa Rich, Wendy, Amy and Aurora Naughton, Wendy Culbert, and Edward Leonard. Ben Gordon and Cerina Gordon contributed to pinning and databasing bees, and Eli Wyman (AMNH) contributed enormously to the databasing effort. Suzan Bellincampi, the Felix Neck staff, and the summer camp kids arranged the logistics for public programs and help with the sampling effort at Felix Neck. Tim Simmons contributed from his personal supply of bee-­‐trapping cups, and John Ascher (AMNH) and Sam Droege (U.S.G.S.) were enormously helpful with advice and support. REFERENCES Schuh, R.T., S. Hewson-­‐Smith, and J.S. Ascher. 2010. Specimen Databases: A case study in Entomology using web-­‐ based software. American Entomologist, Winter 2010: 208-­‐216. Stage, G.I. 2009. Survey of the bees (Hymenoptera: Apoidea) of Penikese and Cuttyhunk Islands. Summary of field work, results, and preliminary conclusions. Final Report to Massachusetts Natural Heritage and Endangered Species Program. 6