Oligositinae

Distinguished from other Trichogrammatidae subfamilies by the combination of: extremely small size (usually under 0.5 mm); forewing with at most one closed cell and reduced setal lines; antennae with 5–7 segments (fewer than most Trichogrammatinae); and simplified tarsal segmentation. Oligositinae lack the distinct wing fringe and more complex venation patterns seen in Trichogrammatinae. Identification to genus requires slide-mounted specimens and microscopic examination of antennal and wing characters.

Extremely small wasps, typically 0.2–0.5 mm in body length. Wings reduced in venation, with few closed cells; forewing often with a single line of setae. Antennae with reduced segmentation, commonly 5–7 segments. Body compact and strongly sclerotized. Coloration usually dark brown to black, occasionally with yellowish markings.

Recorded from multiple continents including North America, Europe, Africa, and Australia. Specific locality records are sparse due to the minute size and difficulty in collecting. Distribution data largely derived from scattered museum specimens rather than systematic surveys.

Presumed parasitoids of insect eggs based on family-level biology of Trichogrammatidae, though direct host records for Oligositinae are extremely limited. Specific hosts remain undocumented for most genera.

• TrichogrammatinaeOverlaps in minute size and general habitus; distinguished by more complex wing venation with multiple closed cells, longer antennae with more segments, and usually more extensive wing fringe.
• PoropoeinaeSimilar reduced size; separated by distinct antennal club structure and different wing venation patterns including characteristic porpoeine wing shape.

• parasitoid
• minute
• wing reduction
• Chalcidoidea

• BugGuide
• iNaturalist taxon
• Catalogue of Life