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Genus Isodontia - Grass-carrying Wasps

Which wasp? - Isodontia auripes Black wasp with orange on legs and abdomen - Isodontia elegans sphecid - Isodontia elegans Thread-waisted Wasp ?  - Isodontia auripes # 178 - Isodontia mexicana Isodontia mexicana Isodontia elegans Isodontia elegans? - Isodontia elegans
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata - Ants, Bees and Stinging Wasps)
No Taxon (Apoid Wasps (Apoidea)- traditional Sphecidae)
Family Sphecidae (Thread-waisted Wasps)
Subfamily Sphecinae
Tribe Sphecini
Genus Isodontia (Grass-carrying Wasps)
Synonyms and other taxonomic changes
Isodontia Patton 1880
6 spp. in 2 subgenera in our area(1), >60 spp. worldwide(2)
Medium-sized dark sphecids, often seen carrying grass to nests.

Hairs on thorax golden
I. elegans - petiole black, legs red, abdomen often red-marked (variable from entirely red to almost entirely black), wings light and often with orange tint

I. exornata - petiole red, legs red, abdomen black, wings dark with some blue reflections

Hairs on thorax pale
I. apicalis - body entirely black, head of female blocky behind eyes, wings always dark and typically with blue reflections

I. mexicana - body black with occasional brown spot on T1, head of female short behind eyes, wings hyaline to dark with blue reflections

Hairs on thorax black
I. apuripes - body black, legs brownish-red, wings dark with strong blue reflections

I. philadelphica - body entirely black, wings dark with strong blue reflections
widely dist.(3)
Open areas, fields, grass
in NC: I. auripes Jun-Oct, I. azteca May-Oct(4); Jul-Aug in MI(5)
Adults take nectar. Larvae are fed Gryllidae (particularly tree crickets) or other Orthoptera.(6)
Life Cycle
Females make nests in a tree, hollow stem or other cavity, divide into sections and close with grass. They provision with Orthoptera (Tettigoniidae, Gryllidae). Can be two generations per year (I. mexicana in PA)
1. Larva 2. Cocoon and food remnants in hollow stem 3. Adult female 4. Adult male. 5. Parasitic fly's puparia.

grass-carrying habits, nest(7); nesting behavior of I. harrisi(8)

Taken from the Internet Reference below (Penn State): The adult wasps emerge from their cocoons in early summer, mate, and the females locate a suitable nest site. She collects blades of grass and grass and hay stems to line the nest cavity. The wasp can be seen flying through the air with the blades trailing beneath her. She lands at the hole and enters, pulling the blade in behind her. After the nest is prepared, she hunts for tree crickets (i.e., Oecanthus sp.), captures and paralyses them with her sting, and transports them to the nest. She deposits eggs in the nest and the emerging larvae will feed on the living, but immobile crickets. When the larvae reach the appropriate size (in 4–6 days at 70–75° F.), they spin a cocoon and pupate. The adult wasps emerge in 2–3 weeks. In Pennsylvania, Isodontia mexicana typically produce two generations per year.
These wasps commonly make their nest in the narrow track found above outer windows.
Internet References
I. mexicana fact sheet. Penn State U.
Dick Walton Natural History Services. Video of nesting behavior and parasites.
Works Cited
1.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
2.Catalog of Sphecidae sensu lato
3.Ascher J.S., Pickering J. (2017) Discover Life bee species guide and world checklist (Hymenoptera: Apoidea: Anthophila)
4.Insects of North Carolina
C.S. Brimley. 1938. North Carolina Department of Agriculture.
5.The Sphecid Wasps of Michigan (Hymenoptera: Sphecidae: Sphecinae), by M.F. O'Brien
6.Solitary Wasps: Behavior and Natural History (Cornell Series in Arthropod Biology)
Kevin M. O'Neill. 2000. Comstock Publishing.
7.The Wasps
Howard Ensign Evans, Mary Jane West Eberhard. 1970. University of Michigan Press.
8.Wasp Farm
Howard Ensign Evans. 1963. Comstock Publishing.