Agathidinae

Agathidinae can be distinguished from other braconid subfamilies by the combination of: forewing veins M+CU not tubular in basal third or more; forewing vein RS complete to wing margin (except Mesocoelus and Plesiocoelus); occipital carina absent; and second submarginal cell of forewing usually present. Genera with elongate genae (Agathis, Cremnops, Disophrys, Bassus) have distinctive narrow, extended faces. The subfamily is noncyclostome, separating it from cyclostome braconids. Bright coloration and flower-visiting behavior in diurnal species contrast with the typically dull, non-floral habits of most other braconids. Tropical species often participate in mimicry complexes.

Agathidines are among the larger braconids, typically 6–10 mm in length. Diurnal members often exhibit bright red and black color patterns. Diagnostic wing venation includes: forewing veins M+CU not tubular in the basal third or more; forewing vein RS complete to the wing margin (except in Mesocoelus and Plesiocoelus); and second submarginal cell of forewing usually present (90% of species). The occipital carina is absent. Several genera (Agathis, Cremnops, Disophrys) possess elongate genae, creating a distinctive narrow, extended facial profile. Members belong to the noncyclostome group of braconids.

Agathidines occupy diverse terrestrial habitats worldwide, with highest diversity in tropical regions. They are frequent visitors to flowers, particularly Asteraceae, where they employ concealed nectar extraction adaptations. Habitat associations reflect host caterpillar distributions, including semi-concealed hosts such as leaf-rollers. Temperate species overwinter within host larvae during first instar. Nocturnal Disophrini occupy habitats where free-living lepidopteran larvae occur.

Worldwide distribution with greater diversity in tropical regions. Some genera (Agathis, Earinus) are more speciose in temperate regions. Ten genera occur in Australia: Amputostypos, Baeognatha, Biroia, Braunsia, Coccygidium, Cremnops, Disophrys, Euagathis, Lytopylus, and Therophilus. Mexico records 24 genera and 127 species. Western Black Sea Region of Turkey has documented 16 species in 3 genera. New World Cremnops species revised across the Americas.

Temperate species such as Earinus elator emerge and seek hosts early in the year, coinciding with bud-burst of host plants' food plants. These species complete metamorphosis before winter to enable early-season host location. Tropical species exhibit year-round activity correlated with host availability.

Adults feed on nectar obtained through specialized concealed nectar extraction adaptations (CNEAs), including elongate malar regions, galea, glossa, and maxillary palps forming a tube. These elongate mouthparts have evolved independently six times within the subfamily. Larvae are internal parasitoids consuming host tissues.

• Lepidoptera larvae - koinobiont endoparasitoidPrimary hosts; most species attack concealed larvae, with Disophrini attacking free-living larvae
• Elasmopalpus lignosellus (Pyralidae) - hostLesser cornstalk borer; recorded host of Trachagathis rubricincta
• Western larch case-bearer - biological control targetControlled by Agathis pumila
• Sugarcane borer - biological control targetControlled by Alabagrus stigma
• Potato tuberworm - biological control targetControlled by Bassus unicoloratus and Agathis gibbosa
• Gypsonoma aceriana - biological control targetForestry pest controlled by Bassus tumidulus

Agathidines have three larval instars. First instars likely seek out and kill competitors within the host. As final instars, they emerge from host caterpillars, feed externally, then spin cocoons. Temperate species overwinter in hosts during first instar. Earinus elator and related temperate species complete metamorphosis before winter, enabling early-season host-seeking. To prevent freezing, some species secrete glycerol- and fatty acid-rich substance over nitrogen-filled meconium, reducing freezing point and preventing ice formation.

Most species are diurnal and frequent flower visitors. Many Disophrini are nocturnal with pale coloration and enlarged ocelli. Mating system in Agathis clavatus involves males searching for females at feeding sites (SFF), a strategy rarely documented in Ichneumonoidea. Males of Alabagrus texanus exhibit short-term memory regarding sites of female emergence; early-arriving males are more successful, while very young and very old males are unsuccessful. Tropical species participate in mimicry complexes. First instar larvae are aggressive competitors, likely killing rival parasitoids in multiparasitized hosts.

Agathidines function as important biological control agents of lepidopteran populations in natural and agricultural ecosystems. Their abundance increases in ecosystems where fluids are harder to obtain, suggesting adaptation to resource-limited environments. Flower-visiting behavior contributes to pollination services, though this role is secondary to parasitoid function.

Multiple species employed in successful biological control programs: Agathis pumila against western larch case-bearer; Alabagrus stigma against sugarcane borer; Bassus unicoloratus and Agathis gibbosa against potato tuberworm; Bassus tumidulus against forestry pest Gypsonoma aceriana. The subfamily represents a significant source of natural enemies for integrated pest management programs.

• IchneumonidaeSimilar size and general appearance; distinguished by Agathidinae's noncyclostome condition, specific wing venation patterns, and frequent flower-visiting behavior
• Other Braconidae subfamiliesAgathidinae distinguished by combination of wing venation characters (M+CU not tubular basally, RS complete, second submarginal cell usually present), occipital carina absent, and noncyclostome condition

• parasitoid
• biological control
• Lepidoptera parasitoid
• flower visitor
• koinobiont
• endoparasitoid

• BugGuide
• Wikipedia
• iNaturalist taxon
• NCBI Taxonomy
• Bug Eric: March 2011
• biodiversity | Blog - Part 44
• Quiz Yourself: 2020 Entomology Games Questions
• Synopsis of Australian agathidine wasps (Hymenoptera: Braconidae: Agathidinae)
• Agathidinae (Hymenoptera: Braconidae) de México, incluyendo nuevos registros
• Review of the systematics of Trachagathis Viereck (Hymenoptera: Braconidae: Agathidinae)
• Studies on the fauna of Agathidinae (Hymenoptera: Braconidae) in the Western Black Sea Region of Turkey Batı Karadeniz Bölgesi Agathidinae (Hymenoptera: Braconidae) Faunası üzerinde araştırmalar
• A revision of the New World species of Cremnops Förster (Hymenoptera: Braconidae: Agathidinae)
• New records of endoparasitoidBassus fabricius, 1804 (Hymenoptera: Braconidae: Agathidinae) species from Turkey
• The genus Aerophilus Szépligeti, 1902 (Hymenoptera, Braconidae, Agathidinae) in China.
• Description of Chilearinus Sharkey gen. nov. and status of Nearctic Earinus Wesmael, 1837 (Braconidae, Agathidinae) with the description of new species.