As you might guess by their name, Potter Wasps (Eumenes fraternus) are wasps having something to do with mud or clay. They are related to Mud Daubers and, like their kin, are solitary in lifestyle. These wasps (10-20mm; 25mm=1 inch) can be easily identified by their distinct narrow and relatively lengthy waist (the junction of the abdomen and thorax).
Potter Wasps are “good guys” in that they provide natural control of many types of caterpillars, and feed on some beetle larvae. The female builds a brood cell that resembles a miniature pot or jug, complete with lid when sealed! The brood cells are made from mud and can be the size of a marble. They attach to the underside of leaves or plant stems, but have also been known to attach themselves to screens and window seals of buildings.
The female Potter Wasp collects water, then, using her mandibles, mixes the water with dry soil. This mud-mixture is then transported to the nesting site where she fashions it into individual pots. The pots may range from ¼” to almost ½”. The process may require hundreds of trips and can take several hours to complete.
Inside the almost finished pot, the female lays a single egg attached by a thread to the inside surface of the structure; she, then, places food inside for the future larva. The food (a healthy diet!) consists of paralyzed prey, caterpillars or beetle larva; then, she seals the pot.
The new adult wasp emerges from the brood cell (aka “pot”) by chewing a hole through the thin side of the pot; this opening is often perfectly round and, therefore, gives the appearance the pot was made on a potter’s wheel!
- Potter Wasp (main photo), Montgomery County, MD, 08/27/2014:https://farm9.staticflickr.com/8666/16294215956_5c1e908d8e_b.jpg; www.marylandbiodiversity.com
- Potter Wasp (noting narrow waist) / Bugguide photo from Perry Babin, ascension Parish, LA, 2009: http://bugguide.net/images/cache/GZH/LPZ/GZHLPZZLVZIHRRWHFHXHBHIHBH6HRRNHFHNHNZLLWZNHTHWHBZILUZGLWZNHFHUHCHQLBHHLBH5HZR9HJHMHVHHLBH.jpg
- Bug Bytes, “Potter Wasps,” by Joe Boggs, 7/17/2014, photo Potter Wasp nest: http://bygl.osu.edu/bygl_archive2015/content/potter-wasps-4
Research References / Resources:
- “Beneficials in the Garden: Potter Wasp,” by Eileen Linton, Galveston County Master Gardeners: http://aggie-horticulture.tamu.edu/galveston/beneficials/beneficial-30_potter_wasp_eumenes.htm
- Bug Bytes, “Potter Wasps,” by Joe Boggs, 7/17/2014; http://bygl.osu.edu/bygl_archive2015/content/potter-wasps-4
- National Wildlife Federation’s Field Guide to Insects and Spiders of North America, by Arthur V. Egans
Author: Jim Revell, Bedford Extension Master Gardener
Source: May 2017 Potter Wasp
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