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Eumenes fraternus

What do they look like?

These potter wasps are small and delicate, about 9.5 to 19 mm long. They have black, shiny bodies with ivory-colored markings on their face and body. The first part of their abdomen is long. They have metallic bluish-brown wings and a wingspan of 8 to 12.5 mm. Females are a little bit bigger than males. They are different from their close relatives because the hairs at the base of their antennae are shorter. (Fontenelle Nature Association, 2008; "Potter Wasp", 2012)

  • Sexual Dimorphism
  • female larger
  • Range length
    9.52 to 19.05 mm
    0.37 to 0.75 in
  • Range wingspan
    8 to 12.5 mm
    0.31 to 0.49 in

Where do they live?

This species of potter wasp lives in eastern North America. They are found from the East Coast west to Ontario, Canada, and in Minnesota, Kansas, Oklahoma, Nebraska, and Texas. (Buck, et al., 2008)

What kind of habitat do they need?

These potter wasps live in forests, at the edge of forests, and in fields with shrubs. They prefer places that have seasons. They are also found around farms or suburban areas where humans live. Juveniles live in small mud domes built by the mother, which are found on shrubs or overhangs from the ground up to the tree line, usually at the edge of a forest. (Fontenelle Nature Association, 2008; Bequaert, 1938; Hubbell, 1989)

  • Range elevation
    1 to 9 m
    3.28 to 29.53 ft

How do they grow?

Female potter wasps lay their eggs in a dome they build out of mud. Whether the egg is male or female depends on a specific part of their genes. After the eggs hatch, the larvae grow and develop in the pot. The mothers bring them paralyzed caterpillars to eat. It is hard to know how they transform from juveniles to adults, because they are hidden in domes when they are developing. Sometimes, they put off developing until after the winter. Once the wasps become adults, they burrow out of the nest. (Buck, et al., 2008; Hubbell, 1989; Hubbell, 1993)

How do they reproduce?

These potter wasps can have 2 to 3 generations in the same season because they live short lives. They mate in the spring, summer, and fall. Males have more than one mate, but researchers aren't sure if females have multiple mates or not. (Hubbell, 1993)

Courtship, mating, and laying eggs happens in the spring, summer, and fall. Potter wasps can have 2 to 3 generations during this time. Females lay one egg in each mud pot they construct. (Hubbell, 1993)

  • How often does reproduction occur?
    Potter wasps can breed two to three times per year, in the warmer months.
  • Breeding season
    Courtship, mating, and oviposition occur in the spring, summer, and fall.

Females build mud domes for their eggs to develop. They also paralyze caterpillars and put them them in the dome for their larvae to eat. After this, they don't watch over the domes or stay around long enough to see their young come out as adults. ("Potter Wasp", 2012)

  • Parental Investment
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female

How long do they live?

Potter wasps live short lives and are able to have 2 to 3 generations within the same season. (Hubbell, 1993)

How do they behave?

Potter wasps live alone or in groups, and are considered solitary. They build small pots in the shape of spheres on plants or overhangs of buildings. Similar to their relatives, they hunt for caterpillars to feed their young. Males aggressively defend good feeding areas from others. Females are not very aggressive and do not defend their nests. (Fontenelle Nature Association, 2008; "Potter Wasp", 2012; Bequaert, 1938; Hubbell, 1993)

Home Range

The size of the home range of potter wasps in not known.

How do they communicate with each other?

These potter wasps are solitary, and don't communicate with other members of their species. Females can defend themselves by stinging. Males of their close relatives can be aggressive against other species of insects if they have found a good feeding area. Their close relatives also use ultraviolet light and light sensors called photodetectors to find the best spots to feed on pollen and nectar. (Hubbell, 1993)

  • Perception Channels
  • ultraviolet
  • chemical

What do they eat?

Potter wasps are omnivorous, so they eat both plants and animals. Adults eat mostly flower nectar from mid-summer through the fall. Young only eat caterpillars their mothers put in their nest. Females can store up to 12 caterpillars in their nests for the young to eat. ("Potter Wasp", 2012; Krombein, 1979)

  • Animal Foods
  • insects
  • Plant Foods
  • nectar

What eats them and how do they avoid being eaten?

Females can sting their predators to protect themselves. This is a warning to future predators, which one kind of fly imitates. Juveniles are hidden from predators in the mud dome where they develop. The outside of the dome is hard, so it protects the larvae. (Krombein, 1979; White, et al., 1998)

What roles do they have in the ecosystem?

Potter wasps are both predators and prey. They also limit the number of caterpillars because they eat so many. (Tavolacci, 2003)

Do they cause problems?

Potter wasps will not sting humans unless they are bothered. They can be annoying or pests to humans if they build pots for their larvae in gardens or houses. However, they are easy to scrape off. (Krombein, 1979)

  • Ways that these animals might be a problem for humans
  • injures humans
    • bites or stings
  • crop pest

How do they interact with us?

Gardeners benefit from potter wasps because eat caterpillars that would otherwise eat their garden. (Hubbell, 1993)

  • Ways that people benefit from these animals:
  • controls pest population

Are they endangered?

This species of potter wasp is not considered endangered or threatened.


Sarah Short (author), University of Michigan-Ann Arbor, Catherine Kent (editor), Special Projects.


2012. "Potter Wasp" (On-line). Accessed February 02, 2012 at

Bequaert, J. 1938. The three Eumenes of Canada and the northeastern United States; with notes on other North American species (Hymenoptera; Vespidae). Bulletin of the Brooklyn Entomological Society, 33: 59-70.

Buck, M., S. Marshall, D. Cheung. 2008. Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region. Canadian Journal of Arthropod Identification, No. 5: 1.

Fontenelle Nature Association, 2008. "EUMENES FRATERNUS" (On-line). NatureSearch. Accessed February 01, 2012 at

Gullan, P., P. Cranston. 2010. The Insects: An Outline to Entomology. Hoboken, New Jersey: Wiley-Blackwell.

Hubbell, S. 1989. A Book of Bees. New York City, New York: Ballantine Books.

Hubbell, S. 1993. Broadsides from the Other Orders: A Book of Bugs. New York City, New York: Random House.

Krombein, K. 1979. Superfamily Vespoidea. Pp. 1469-1522 in K Krombein, P Hurd, D Smith, B Burks, eds. Catalog of Hymenoptera in America north of Mexico Vol. 2, Apocrita (Aculeata). Washington: Smithsonian Institution Press.

Tavolacci, J. 2003. Insects and Spiders of the World. New York City, New York: Marshall Cavendish.

White, R., D. Borror, R. Peterson. 1998. A Field Guide to Insects: America North of Mexico. New York City, New York: Houghton Mifflin Harcourt.

University of Michigan Museum of ZoologyNational Science Foundation

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Short, S. 2013. "Eumenes fraternus" (On-line), Animal Diversity Web. Accessed April 15, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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