Hair Stalk Gall Wasp
Andricus pedicellatus
This record describes Andricus pedicellatus (species). Recorded family: Cynipidae. Recorded order: Hymenoptera.
Identification and Appearance

This wasp makes thin, stalked, pointed galls along margins of blue, valley, scrub, and Oregon oak leaves. Galls develop in early spring; adults emerge between April and June.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera (Ants, Bees, Wasps and Sawflies)
- Superfamily
- Cynipoidea
- Family
- Cynipidae (Gall Wasps)
- Tribe
- Cynipini
- Genus
- Andricus
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
About Flies: the wider group
Order-level background for Hymenoptera, the group containing Andricus pedicellatus. 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 Hair Stalk Gall Wasp (4)
Photo credits: Contributed by Joyce Gross; Additional contributions by ceiseman
Frequently Asked Questions About Hair Stalk Gall Wasp
What is Hair Stalk Gall Wasp?
Hair Stalk Gall Wasp (Andricus pedicellatus) is a species in the family Cynipidae, within the order Hymenoptera.
How big is Hair Stalk Gall Wasp?
Up to 20mm tall and 2mm wide at bulge at tip.
How do you identify Hair Stalk Gall Wasp?
This wasp makes thin, stalked, pointed galls along margins of blue, valley, scrub, and Oregon oak leaves. Galls develop in early spring; adults emerge between April and June.
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