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Asecodes Förster, 1856 comparative info return to: prev home
Transverse frontal groove v-shaped; scrobal grooves ending separately at transverse groove, extending ventrally below toruli; interscrobal ridge meeting transverse groove; occiput with median furrow (not unique: present in some Closterocerus, Achrysocharoides, Ionympha, Neochrysocharis, etc.). Clypeus not delimited by sutures (but sometimes faintly indicated). Flagellum nearly always with an ambiguous number of funicular vs. claval segments, from 1 claval segment and 4 funicular segments to 3 claval segments and 2 funicular segments; all postanellar flagellomeres at least slightly longer than broad; flagellum with L-shaped (type 2) peg sensilla. Mesoscutal midlobe with 2 pairs of setae; notauli bent sharply laterad at their anterior ends. Postmarginal vein shorter than or subequal stigmal vein length; 2-3 rows of setae radiating from stigmal apex in some species; stigmal vein unusually short in many species (as compared to similar small-bodied genera); radial cell bare or setose; forewing usually hyaline, sometimes with faint infuscate spots near the venation, but only rarely with a transverse (A. reticulatus (Kamijo)) or longitudinal (A. turcicus (Nees)) band. Compare with: Closterocerus, Chrysocharis (Zaommomyia), Ionympha, Ceranisus, Thripobius, Achrysocharoides, Chrysonotomyia.

1a-b: Asecodes face (left), and forewing (right)

2a-b: Asecodes occiput, showing variation in length of occipital furrow (of)

Biology: Larval or pupal parasitoids of Coleoptera or (rarely) Diptera.

Comments: Usually difficult to identify, nearly always strongly collapsed. The best identification characters, such as facial sutures, are strongly affected by facial collapse. Forms a major part of a tentative group including Ionympha, Closterocerus, and the Omphale-group, although the putative synapormorphies of this group are not as convincing as I would like. The differences between this genus and Closterocerus are especially vague, and I suspect that the two genera are not separable at all in any consistent way. One often overlooked issue is the close similarity of the Ceranisus group to these genera, distinguished only by the sulcus across the vertex in the Ceranisus group, along with a lack of other unique characters such as the modified volsellar setae of Omphale. While these groups can be defined easily by their hosts, their morphological similarity should not be ignored. This genus was synonymized under Closterocerus by Gumovksy (2001), but Burks et al. (2011) removed it from synonymy because molecular data indicated that it and Neochrysocharis are more closely related to Pediobius.

Comparative information:

Closterocerus: Flagellum beyond anelli with transverse segments, and/or mesoscutum with 1 pair of setae on the midlobe. Scape in males with placoid sensilla present only near its apex (except for C. brachyphagus). Forewing in some species with 2 or more transverse bands (at most with a single transverse band in Asecodes). At most 1 row of setae radiating from stigma (2 in some species of Asecodes). Stigmal vein elongate in most species, with a distinctly petiolate stigma. Transverse frontal groove straight or nearly so in the subgenus Achrysocharis. Can be very difficult to distinguish when the number of claval segments is in doubt and the postanellar flagellomeres are longer than broad, requiring species-level identification.

Chrysocharis (Zaommomyia): Heads of peg sensilla of flagellum rounded, symmetrical. Postmarginal vein 1.6-2.3x stigmal vein length; stigma without radiating rows of setae. These two groups may be very closely related, but I am unable to verify this suspicion at this time other than by pointing out the scrobal depressions extending below the toruli in both.

Neochrysocharis: Heads of peg sensilla of flagellum rounded, symmetrical. Forewing with no setal tracks radiating from stigma, and radial cell always setose. Stigma characteristically elongate, petiolate. Many species with transverse postanellar flagellomeres.

Ionympha: Mandibles very long and narrow, with several tiny dorsal teeth and 2 large apical ones. Gena with strong incision for base of mandible to fit into when open. Scape with sensory pores present only at apex in males. Males with subbasal pale spot on gaster. Ovipositor very short, its base very far posteriad.

Ceranisus, Thripobius: Head with a complete sulcus across vertex; frontal grooves reaching above ocellus in Thripobius. Parasitoids only of larval thrips. Can be easily confused with Asecodes with long forewing fringe setae, especially if the head is collapsed as it so often is in these species.

Achrysocharoides: Eyes very strongly setose. Transverse frontal groove always straight, not v-shaped (but can be bent medially if face is collapsed); scrobal grooves not extending below toruli. Toruli often very broadly separated. Mesoscutum and especially scutellum often with distinct groups of pits or longitudinal foveae. No setal tracks radiating from stigma. Usually easily distinguished.

Chrysonotomyia: Clypeus set off by distinct sutures. Transverse frontal groove straight, not v-shaped (but may be bend if face is collapsed), scrobal grooves not extending ventrally below toruli. Mesoscutal midlobe with 1 pair of setae (the posterior pair). Confusable mainly due to the setal tracks radiating from stigma.

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References

Burks, R.A., Heraty, J.M., Gebiola, M. & Hansson, C. 2011. Combined molecular and morphological phylogeny of Eulophidae (Hymenoptera: Chalcidoidea), with focus on the subfamily Entedoninae. Cladistics 27: 581-605.

Gumovsky, A.V. 2001. The status of some genera allied to Chrysonotomyia and Closterocerus (Hymenoptera: Eulophidae, Entedoninae), with description of a new species from Dominican Amber. Phegea 29(4): 125-141.

Hansson, C. 1994. The classification of Chrysonotomyia Ashmead and Teleopterus Silvestri (Hymenoptera: Eulophidae), with a review of species in the Nearctic region. Proceedings of the Entomological Society of Washington. 96: 665-673.

Hansson, C. 1996. The status of the genera Asecodes Förster, Ionympha Graham and Teleopterus Silvestri (Hymenoptera: Eulophidae) with a review of Nearctic species. Entomologica Scandinavica. 27: 159-167.

Schauff, M.E. 1991. The Holarctic genera of Entedoninae (Hymenoptera: Eulophidae). Contributions of the American Entomological Institute 26.

Image credits: 1a-b: Schauff (1991). 2a-b: Hansson (1996).