Dasyhelea

Borkent, Art, 2024, The Phylogeny of the Genera of Biting Midges (Diptera: Ceratopogonidae) of the World, Zootaxa 5438 (1), pp. 1-274 : 222

Dasyhelea :

- The frontoclypeus T-shaped ( Dominiak 2012) ( Figs. 11A , 14B ), with a line of weakness (D. ( Dicryptoscena Enderlein )) or a partial membranous separation or only membrane between the dorsal transverse portion (all remaining Dasyhelea ) and the ventral longitudinal portion (frontoclypeus one unit in all other ceratopogonids).

- The scape with a pronounced prong on its ventral margin abutting an extension of the anterior portion of tentorial arm. This feature was discussed by Borkent et al. (1987) as character 11.

- Male antenna with flagellomeres 10–12 each with double whorl of plume or elongate setae (see Serromyia ).

- Male antenna with flagellomeres 2–12 each with basal striations and in some, present also on flagellomeres 1 and 13. This was discussed by Borkent et al. (1987, character 1).

- Acrostichal setae in a double row. This feature is unique within Ceratopogonidae , which generally have a single row of acrostichal setae, most clearly defined anteriorly. Washingtonhelea may have a double row but if so, it is not as clearly defined as in Dasyhelea (visibility was poor). Other arrangements of acrostichal setae in Ceratopogonidae are discussed under characters 58 and 59 and “Uncertain Character States”.

- foretibial spur absent. This feature is nearly unique in the family but is also absent in Baeodasymyia . The feature was discussed by Borkent & Craig (1999, character 3)

- Hind tibia without a tibial spur. Borkent & Grogan (1995; their character 2) described this as a synapomorphy of Ceratopogon , noting that it was also absent in a few other genera, all of which are clearly unrelated to Ceratopogon . There have been a few independent losses within the family. It is often difficult to determine whether a short spur is present among the apical spines of the hind tibia.

- Larva with four large bodies in at least the prothorax and metathorax that appear to be unique to this genus. Keilin (1921) suggests that these are “completely filled with bacteria” and that they are transmitted transovarially.

- Egg c-shaped. This is unique feature in the Culicomorpha and was discussed by Borkent (1995, character 25).

Figures

FIGURE 11. Head capsules of female Ceratopogonidae, in anterior view.A. Dasyhelea sp. B. Culicoides variipennis Coquillett. C. Culicoides paraimpunctatus Borkent.D. Paradasyhelea macfiei Spinelli & Grogan. E. Washingtonhelea n. sp. F. Ceratopogon boomerangus.

FIGURE 14. Head capsules of female Ceratopogonidae, in anterior view.A. Austroconops mcmillani. B. Dasyhelea (Sebessia) sp. C. Forcipomyia fuliginosa. D. Atrichopogon sp.