HymenopteraCynipidae – Gall Wasps

Blackberry Knot Gall Wasp

Diastrophus nebulosus

This record describes Diastrophus nebulosus (species). Recorded family: Cynipidae. Recorded order: Hymenoptera.

Identification and Appearance

Blackberry Knot Gall Wasp - Diastrophus nebulosus
Contributed by Charley Eiseman; Additional contributions by v belov

Induces galls in blackberry stems: Rounded or long stem swellings, sometimes with 4 or 5 deep longitudinal furrows, length 2 to 6 inches. Parasitoids include this eurytomid:

Classification

Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Hymenoptera (Ants, Bees, Wasps and Sawflies)
Superfamily
Cynipoidea
Family
Cynipidae (Gall Wasps)
Tribe
Diastrophini
Genus
Diastrophus

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 Diastrophus nebulosus. 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.

Explore Hymenoptera families and species →

Photos of Blackberry Knot Gall Wasp (5)

Blackberry Knot Gall Wasp - photo 1
Contributed by Charley Eiseman; Additional contributions by v belov
Blackberry Knot Gall Wasp - photo 2
Contributed by Charley Eiseman; Additional contributions by v belov
Blackberry Knot Gall Wasp - photo 3
Contributed by Charley Eiseman; Additional contributions by v belov
Blackberry Knot Gall Wasp - photo 4
Contributed by Charley Eiseman; Additional contributions by v belov
Blackberry Knot Gall Wasp - photo 5
Contributed by Charley Eiseman; Additional contributions by v belov

Photo credits: Contributed by Charley Eiseman; Additional contributions by v belov

How we use and review source data. Source count does not imply independent verification.

Photo credits: Contributed by Charley Eiseman; Additional contributions by v belov. Contributors retain copyright over their individual contributions.