Understanding bee diversity in New York

We estimate there are 416 bee species in New York state, comprising 42 of the 425 genera of bees in the world (Michener 2007). Our most common (and speciose) genera are Andrena, Lasioglossum, Nomada, Sphecodes, Megachile, Colletes, Osmia, Hylaeus, Melissodes, Bombus and Coelioxys.

The downloadable species list categorizes bees by species, subgenus, family and subfamily. Additional info in the form of life history notes, conservation status and references make this an invaluable tool.

The total number of bee species in New York state is estimated to be 416 species in 47 genera.

This section of the website, focusing on the bee species found in New York was provided by Bryan Danforth and Maria van Dyke. We assembled this list of New York bees using the American Museum of Natural History’s Arthropod Easy Capture database (Schuh et al. 2010, Schuh 2012). Data on New York bees were collected as part of an NSF-funded research grant to John Ascher, Jerome Rozen Jr. and Douglas Yanega titled “Collaborative Databasing of North American Bee Collections within a global informatics network.” Specimen records come from major North American insect collections, including American Museum of Natural History, Cornell University, University of Connecticut and Rutgers University (in the eastern U.S.) and the University of California, Riverside, USDA-ARS Bee Biology and Systematics Laboratory at Utah State University, UC Davis, UC Berkeley, California State Collection of Arthropods, Los Angeles County Natural History Museum (in the western U.S.). We supplemented the list with regional (e.g., Giles & Ascher 2006, Matteson et al. 2008, Feteridge et al. 2008, Ascher et al. 2014) and crop-based (e.g., Russo et al. 2015) surveys of bee diversity in New York. Notes on the biology and distribution of these bee species can be found at the Discover Life website. Note that this is likely an incomplete list of New York bees because no state survey has ever been conducted on the wild bees of New York state.

References

  • Ascher, J.S., S. Kornbluth, and R.G. Goelet (2014). Bees (Hymenoptera: Apoidea: Anthophila) of Gardiners Island, Suffolk County, New York. Northeastern Naturalist 21(1): 47-71.
  • Feteridge, E.D., J.S. Ascher, G.A. Langellotto (2008). The bee fauna of residential gardens in a suburb of New York City (Hymenoptera: Apoidea). Annals the Entomological Society of America 101(6): 1067-1077 
  • Giles, V., and J.S. Ascher (2006). A survey of the bees of the Black Rock Forest Preserve, New York. Journal of Hymenoptera Research 15: 208-231.
  • Matteson, K.C., J.S. Ascher, and G.A. Langellotto (2008). Bee richness and abundance in New York city urban gardens. Annals of the Entomological Society of America 101: 140-150.
  • Russo, L., M.G. Park, J. Gibbs, B.N. Danforth (2015). The challenge of accurately documenting bee species richness in agroecosystems: bee diversity in eastern apple orchards. Ecology and Evolution 5(17): 3531-3540.
  • Schuh, R.T. (2012). Integrating specimen databases and revisionary systematics. Zookeys 209: 255-267.
  • Schuh, R.T., S. Hewson-Smith, and J.S. Ascher (2010). Specimen databases: a case study in entomology using web-based software. American Entomologist 56(4): 206-216.

What are wild bees?

Wild bees are a diverse group of unmanaged pollinator species. They are often solitary and live in burrows excavated into the ground, in wood or in pithy plant stems.

What bees live in New York?

Bees of New York

The majority (54%) of bees in New York State are digger bees (ground-nesting, solitary bees, such as Andrena, Lasioglossum, Colletes and Melissodes). Species of Andrena are typical of ground-nesting bees in their life history. At the start of the nesting season (in the spring, summer or fall, depending on the species), female Andrena begin constructing burrows in the soil. At the end of these subterranean burrows they construct brood cells, which are lined with waterproof secretions from the Dufour’s gland. Once a brood cell has been constructed, a female provisions it with a mixture of pollen and nectar collected from flowering plants in the vicinity of the nest. Foraging ranges in these solitary bees are small – on the order of 500 m maximum – so nests are typically close the floral resources. Once the provisions have been collected, the pollen/nectar mixture is sculpted into a spherical pollen ball and an egg is laid on top. The brood cell is then closed and the female begins constructing a new brood cell. Brood cells range in depth from just a few inches to several feet. A typical solitary female might produce just 10-15 offspring over a period of two to three weeks of active foraging.

While the majority of bees in New York state are ground-nesting, several species also make nests in preexisting cavities, such as twigs, hollow stems, beetle burrows, or in sites above ground. These aboveground, cavity nesters include mason bees, wool carder bees and various resin bees. Mason bees in New York include genera such as Osmia, Hoplitis, Prochelostoma and Heriades. Mason bees comprise roughly 7% of the species of bees in the state. Other cavity- and stem-nesting bees include the leaf-cutter bees in the genus Megachile (Sheffield et al. 2011), carder bees in the genus Anthidium, Pseudoanthidium and Paranthidium, and the yellow-faced bees in the genus Hylaeus. Megachile females line their cells with circular pieces of leaf that they cut from rosebushes and other plants. Hylaeus females line their burrows (constructed in plant stems or other hollow tubes) with a cellophane-like material produced by the Dufour’s gland. Hylaeus are unusual bees because they carry pollen internally and not externally, as do most pollen-collecting bees.

Another important group of bees are the carpenter bees. In North America we have both small (Ceratina) and large (Xylocopa) carpenter bees. These bees construct nests in wood or preexisting cavities. Xylocopa virginica is a common bee in New York. Nests are conspicuous because males hover in front of the nests (typically located in fence posts, wooden park benches and houses) and engage in aggressive territorial battles.

Cleptoparasitic bees comprise 23% of the bee species in New York. The two largest genera of cleptoparasitic bees in New York are Sphecodes and Nomada. Parasitic bees are fascinating creatures. They have lost the morphological structures associated with nest construction and pollen collection in most other bees. Instead of constructing and provisioning their own brood cells, parasitic bees enter the nests of other bees (usually when the host female is away) and lay their eggs within the host nest. Once the host female has laid her egg and closed the cell, the parasitic larva hatches from its own egg and kills either the host egg or young larva, then feeds on the host’s pollen. Parasitic bees have devious methods for hiding their eggs from the host females. For example, Nomada and relatives (in the subfamily Nomadinae) put their eggs in the cell wall of the host bee’s nest.

So far, the vast majority of bees we have mentioned are solitary (or parasitic). Important eusocial bees in New York state include both advanced eusocial taxa in which queens and workers are morphologically distinct (such as Apis mellifera, the introduced honey bee) and primitively eusocial taxa, in which queens and workers are distinguishable from each other based only on size or behavior. Important primitively eusocial taxa include Bombus (bumble bees; Apidae), as well as Augochlorella, Halictus and some species of Lasioglossum (Halictidae). We estimate that approximately 19% of the bee species in New York are eusocial.

References

  • Kilpatrick, S.E., J. Gibbs, M.M. Mikulas, S. Spichiger, N. Ostiguy, D.J. Biddinger, and M.M. López-Uribe. (2020). An updated checklist of the bees (Hymenoptera, Apoidea, Anthophila) of Pennsylvania, United States of America. Journal of Hymenoptera Research 77: 1-86.
  • Michener, C.D. (2007). The Bees of the World. Baltimore: Johns Hopkins University Press.
  • Sheffield, C.S., C. Ratti, L. Packer, and T. Griswold (2011). Leafcutter and mason bees of the genus Megachile Latreille (Hymenoptera: Megachilidae) in Canada and Alaska. Canadian Journal of Arthropod Identification 18: 1-107.

Managed bee species

Honey bees

The honey bee, Apis mellifera, is the most widely used managed bee worldwide. Between 3,000 and 4,000 beekeepers maintain over 80,000 colonies in the state. Commercial migratory beekeepers transport their hives across the U.S. to pollinate almonds in California, apples and pumpkins in Pennsylvania, blueberries and cranberries in Maine, citrus in Florida, and cucumbers and blueberries in New Jersey [1]. Providing pollination services is a growing business and contributes a significant portion of income to beekeepers in addition to profits from honey and other hive products.

Honey bees are generalist pollinators that visit apples, pears, sweet cherries, apricots, cucumbers, melons, cucurbits, green beans, field tomatoes, peppers, peaches, berries, alfalfa and oilseed crops.

Bumble bees

The common eastern bumble bee, Bombus impatiens, is a major contributor to greenhouse pollination in the Northeast. Bumble bees’ midsize colonies (up to a few hundred individuals) and foraging ranges (about 300 m) allow them to live and feed in greenhouses. Unlike honey bees, bumble bees can buzz-pollinate to release firmly held pollen from certain plants, such as tomatoes, and are valuable for that regard. Bumble bees, both wild and managed, pollinate a variety of crops, including peppers, cucumbers, melons, cucurbits, orchard fruits, berries, oilseeds and cover crops.

Alfalfa leafcutter bees

The alfalfa leafcutter bee, Megachile rotundata, is a non-native species that was introduced to North American in the 1930s to increase pollination of alfalfa. They create tubular nests in flower stems and rotting wood and adapt well to manmade trap nests, allowing them to be “managed” to some degree. In addition to alfalfa, these bees have also been documented to pollinate blueberry and clover.

Mason bees

Two species of mason bees are managed in New York. The blue orchard bee, Osmia lignaria, is native with a striking blue color. The Japanese orchard bee, Osmia cornifrons, is non-native and was recently introduced to assist in orchard pollination. Like the alfalfa leafcutter bee, both of these mason bees can be managed to an extent by placing trap nests containing purchased pupae in orchards to assist with pollination.

Reference

1. vanEngelsdorp, D., et al., Idiopathic brood disease syndrome and queen events as precursors of colony mortality in migratory beekeeping operations in the eastern United States. Preventive Veterinary Medicine, 2013. 108: p. 225-233.

Ground-nesting bees in your backyard

Not all bees live in hives like honey bees do. In fact, 70% of all the 20,000 species of bees nest underground. In North America, most of these ground bees become active in early spring. Nests of these bees are easy to identify above ground because of the conical piles of dirt with a large hole in the middle that serves as the entrance to the bee burrows.

One of the most abundant ground-nesting bees in the Northeastern and Midwestern regions of North America is Colletes inaequalis. Even though this bee is solitary, meaning that every individual female builds her own nest, it is also a gregarious nester. Many females (hundreds and sometime thousands) build their nests next to each other. The nests are obvious above ground because of the conical piles of dirt with a hole in the middle. Colletes inaequalis has a strong preference for sandy soils on south facing slopes. Thus, if you have these conditions in your backyard, you may find these bees showing up every year where you live. Unlike social bees and wasps, solitary species are not aggressive insects even though females do have sting. These bees will not attempt to sting humans unless handled. Most activity at nest sites in early spring is of males looking for females to mate with – male bees cannot sting.

Besides C. Inaequalis, many other ground-nesting native bees can be found in your backyard. For example, species of the bee genera Agapostemon, Andrena, Halictus and Lasioglossum are also abundant in North America. All of these native bee species provide important ecological services that include pollinating many of the plants in your garden and nearby. Specifically, Colletes inaequalis and similar looking Andrena species are important pollinators of spring crops like apples, blueberries and cherries. Therefore, we do not consider these bees as pests and strongly recommend avoiding the use of chemicals to control them. Pesticides are bad for humans and beneficial insects. Usually, using water over the area of the nest is enough to encourage the bees to look for a different nesting area. However, due to their beneficial role as pollinators and their lack of aggressive behavior, please consider maintaining these important bee pollinators in your backyard!