Lyon's Gall Wasp
Heteroecus lyoni
This record describes Heteroecus lyoni (species). Recorded family: Cynipidae. Recorded order: Hymenoptera.
Identification and Appearance

The larvae of this wasp induce stem galls on Quercus palmeri (Palmer's oak) in California. It's not known to induce galls on any other oak species.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera (Ants, Bees, Wasps and Sawflies)
- Superfamily
- Cynipoidea
- Family
- Cynipidae (Gall Wasps)
- Tribe
- Cynipini
- Genus
- Heteroecus
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Geographic Range
California.
About Flies: the wider group
Order-level background for Hymenoptera, the group containing Heteroecus lyoni. 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 Lyon's Gall Wasp (2)
Photo credits: Contributed by Joyce Gross
Frequently Asked Questions About Lyon's Gall Wasp
What is Lyon's Gall Wasp?
Lyon's Gall Wasp (Heteroecus lyoni) is a species in the family Cynipidae, within the order Hymenoptera.
How do you identify Lyon's Gall Wasp?
The larvae of this wasp induce stem galls on Quercus palmeri (Palmer's oak) in California. It's not known to induce galls on any other oak species.
Where is Lyon's Gall Wasp found?
Range: California.
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