Agathirsia nigricauda

Distinguished from congeners by the dark coloration of the cauda (reflected in species epithet). Within Agathirsia, identification to species level requires examination of wing venation, antennal segment counts, and genitalic structures. Separation from other Agathidinae genera (e.g., Bassus, Cremnops) based on combination of: forewing with areolet absent or reduced, hindwing with basal cell open or closed, and specific patterns of sculpture on the mesoscutum and propodeum. Specific diagnostic features for A. nigricauda versus other Agathirsia species not available in published keys.

As a member of Agathidinae, likely possesses the characteristic elongated, slender body form with a narrow petiole (wasp waist). The species name 'nigricauda' indicates dark coloration of the terminal abdominal segments. Forewings typically with reduced venation characteristic of Braconidae, including absence of vein 2m-cu. Antennae multi-segmented and filiform. Body size and precise color pattern require specimen examination.

Recorded from Middle America and North America. Specific countries or ecological regions within these broad areas not documented in available sources.

As a member of Braconidae subfamily Agathidinae, functions as a koinobiont endoparasitoid of Lepidoptera larvae. Koinobiont parasitoids allow hosts to continue feeding and developing after parasitism, eventually killing the host prior to pupation. Specific host records for A. nigricauda not documented.

• Other Agathirsia speciesShare genus-level characters including wing venation patterns and body form; require detailed morphological examination for separation
• Bassus spp.Convergent body form within Agathidinae; distinguished by differences in forewing areolet structure and propodeal sculpture
• Cremnops spp.Similar size range and parasitoid lifestyle; separated by antennal segment count and details of hindwing venation

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life