Acaenitinae

Description

Acaenitinae is a small subfamily of medium to large sized wasps. Most females (except the genera Leptacoenites and Procinetus, none of which occur in northern Europe) are easily recognized by the hypopygium being unusually large and elongate, sometimes beginning around the middle of the abdomen and reaching to its apex. Some other useful characters are: clypeus often with a median tooth; the labrum often widely exposed; hind wing with nervellus intercepted above the center; fore and mid claws sometimes with subapical tooth; hind coxae and trochanters usually quite long; propodeum rather flat (without distinct dorsal and posterior slopes); ovipositor long and without notch. While universal characters are rare, most species are redily recognized as Acaenitines by their general shape.

Ecology

Saproxylic beetles make up the vast majority of host records and therefore seem to be the preferred group by Acaenitinae. There are however some records of rearings from xylophagous Hymenoptera and Lepidoptera (of varying levels of credibility). While the lifcycles are often poorly studied, Acaenitus dubitor is known to be a koinobiont endoparasitoid, suggesting a similar mode of development for the rest of the subfamily.

Distribution

Many species are likely highly threatened or extinct in northern Europe. Only about half of the species have recent records, and several of those are single isolated finds in diminishing environments. Since most species are large and easily recognized it is unlikely that they would remain unnoticed for extended periods of time. Two species, Coleocentrus excitator and Phaenolobus terebrator, listed as LC and NT in Finland respectively, seem to be doing well.

Acaenitinae has a near cosmopolitan distribution.

References

Broad, G. R., Shaw, M. R., & Fitton, M. G. (2018). Handbooks for the identification of British insects Vol. 7, part 12 Ichneumonid wasps : (Hymenoptera: Ichneumonidae): their classification and biology. Royal Entomological Society of London

ZWAKHALS, C. J., 1989. THE ACAENITINAE FROM THE NETHERLANDS AND THE HOST OF ACAENITUS DUBITATOR (HYMENOPTERA: ICHNEUMONIDAE). - EN7: BER., AMST:49 (2):21-25.

Varga, A., (2013). A review of the subfamily Acaenitinae Förster, 1869 (Hymenoptera, Ichneumonidae) from Ukrainian Carpathians. Biodiversity Data Journal 1: e1008. doi: 10.3897/BDJ.1.e1008

Bischoff, H., 1915. Eine neue deutsche Ichneumonide. (Hym.) Coleocentrus soldanskii. Berliner entomologische Zeitschrift. 1: 75-76

SLU Artdatabanken (2024). Artfakta: Acaenitinae. https://artfakta.se/taxa/1000026 [2024-07-03]

Finlands Artdatacenter (2024). LAJI.FI: Acaenitinae. https://laji.fi/sv/taxon/MX.308519 [2024-07-03]

BugWeb

Acaenitinae

Keys

Northern European species

Gallery

References