HymenopteraEulophidae2 data sources

Quadrastichus

This record describes Quadrastichus (genus). Recorded family: Eulophidae. Recorded order: Hymenoptera.

Identification and Appearance

A large genus with a worldwide distribution. Very difficult to identify to species level. Female funicle 3-segmented and male 4-segmented, notauli complete. Aprostocetus : Submarginal vein in forewing with 2-5 (usually 3 or more) dorsal setae, propodeum with an unbranched medial carina (ridge). Tetrastichus : Submarginal vein in forewing with one dorsal seta, propodeum with a carina (ridge) branched like an inverted Y. Quadrastichus and Oomyzus also share the single seta on the submarginal vein with Tetrastichus, but they lack the Y-shaped propodeal carina. Unless identified by a recognized expert, explain how the specimen was identified and include photos of key features. Parasitoids of Diptera, Cynipidae, Coleoptera, or eriophyid mites within galls. Graham M.W.R. de V. (1991) A reclassification of the European Tetrastichinae (Hymenoptera: Eulophidae): revision of the remaining genera. Memoirs of the American Entomological Institute, 49: 1-322. No additional images available for this species.

Classification

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera (Ants, Bees, Wasps and Sawflies)
Superfamily: Chalcidoidea
Family: Eulophidae
Subfamily: Tetrastichinae
Genus: Quadrastichus

Imported taxonomy record. Source availability varies; see the source references and editorial policy below.

Habitat and Range

Seasonal Activity

All year.

Diet and Behavior

Life History

Parasitoids of Diptera, Cynipidae, Coleoptera, or eriophyid mites within galls.

Additional species information

Recorded status

Unknown.

About Flies: the wider group

Order-level background for Hymenoptera, the group containing Quadrastichus. 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.

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