Oak Pea Gall Wasp
Acraspis pezomachoides
This record describes Acraspis pezomachoides (species). Recorded family: Cynipidae. Recorded order: Hymenoptera.
Identification and Appearance
Forms galls on veins of white oak ( Quercus alba ). Spherical or ellipsoidal, naked and faceted to spiny, young galls light green, rose-tinted, becoming yellow or brown, spines when present purplish red, diameter 1/4 inch, two-celled. Parasitoids: Eurytoma (Eurytomidae) Ormyrus (Ormyridae)
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera (Ants, Bees, Wasps and Sawflies)
- Superfamily
- Cynipoidea
- Family
- Cynipidae (Gall Wasps)
- Tribe
- Cynipini
- Genus
- Acraspis
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Seasonal Activity
"Galls are full-grown in early July. In D.C. area galls contained pupae on Sept. 1 and adults Oct. 20. They probably emerge in Nov and Dec. The type was found in box on Jan. 7."
About Flies: the wider group
Order-level background for Hymenoptera, the group containing Acraspis pezomachoides. Species-specific details appear above.
Group overview
Hymenoptera includes over 150,000 described species of ants, bees, wasps, and sawflies. Earth harbors approximately 20 quadrillion (20×10^15) ants, with a combined biomass of ~12 megatons of dry carbon - exceeding the combined biomass of all wild birds and mammals (PNAS, 2022).
Ecological role of the group
About 35% of the world's food crops depend on animal pollinators. The chocolate industry, valued at over $100 billion, depends on pollinating flies and midges. Ants are the dominant soil engineers in most terrestrial ecosystems, turning more soil than earthworms in many habitats.
Economic and practical significance of the group
Pollinators contribute $235-577 billion worth of annual global food production (FAO). In the U.S., bee pollination alone benefits crops valued at $18 billion annually, and honey bees are responsible for $5.4 billion in agricultural productivity. Between April 2023-2024, 55.1% of managed honey bee colonies were lost. The U.S. bee population dropped from 5 million to 2.5 million.
Recorded sources for this group: FAO, USDA, EPA, PNAS (2022), US Fish & Wildlife Service. Imported estimates may describe particular regions or reporting periods.
Photos of Oak Pea Gall Wasp (5)
Photo credits: Contributed by Charley Eiseman