Adelognathinae

Adelognathinae can be distinguished from other ichneumonid subfamilies by their association with sawfly hosts and their characteristic ectoparasitoid biology. Females possess an ovipositor modified for spreading adhesive substances rather than for egg deposition, as eggs are laid directly from the genital opening onto the host dorsum. Final instar larvae are relatively featureless compared to other ichneumonid larvae.

Associated with habitats supporting Tenthredinidae sawfly larvae, particularly on Ribes uva-crispa (gooseberry) and related host plants. The subfamily occurs in environments where sawfly larvae feed on woody or herbaceous vegetation.

Documented from Britain; broader distribution within the Holarctic likely but insufficiently documented.

Univoltine; adults active during periods when host sawfly larvae reach late developmental stages.

Adult females host-feed on haemolymph and sometimes other tissues obtained from wounds made by their mandibles. Larvae are ectoparasitoids feeding on host tissues.

• Nematus leucotrochus - primary hostTenthredinidae sawfly larvae, late-stage
• Ribes uva-crispa - host plantfood plant of primary host sawfly

Univoltine. Eggs deposited on host dorsum. Larval development completes in approximately 70 hours at 18–22°C, with five instars detected. Host continues feeding for roughly the first half of larval development. Winter passed as prepupa enclosed in a tough cocoon.

Females temporarily paralyze hosts with venom injection during oviposition. Prior to egg deposition, females spread adhesive from the ovipositor to prepare the attachment site. Host-feeding may occur concurrently or non-concurrently with oviposition; when non-concurrent, it may be destructive or non-destructive. Host defensive reactions to prospecting females have been observed. Some species are slightly gregarious.

Ectoparasitoid of tenthredinid sawfly larvae, potentially contributing to regulation of sawfly populations on Ribes and related plants.

• other Ichneumonidae subfamiliesAdelognathinae differs in depositing eggs directly from the genital opening rather than through the ovipositor, and in their specific association with sawfly larvae as hosts
• idiobiont ectoparasitoid waspsSome Adelognathus species are koinobiont (host continues development after parasitism), distinguishing them from typical idiobiont ectoparasitoids that permanently paralyze hosts

• ectoparasitoid
• koinobiont
• sawfly parasite
• univoltine
• non-ovipositor egg deposition

• BugGuide
• iNaturalist taxon
• NCBI Taxonomy
• The taxonomy and biology of the BritishAdelognathinae(Hymenoptera: Ichneumonidae)
• Biology, early stages and description of a new species of Adelognathus Holmgren (Hymenoptera: Ichneumonidae: Adelognathinae)