Echinohelea, Macfie, 1940

Borkent, Art, 2024, The Phylogeny of the Genera of Biting Midges (Diptera: Ceratopogonidae) of the World, Zootaxa 5438 (1), pp. 1-274 : 232-233

Echinohelea :

- Females have strongly modified mouthparts, with substantial fusion and the formation of a basal rostrum as a single unit. The anterior tentorial pit is situated on the frontoclypeus and it lacks sutures to the frons between the eyes and the anterodorsal prong of the tentorium is unique in the family (all others have at least one of the sutures). The labrum is apically tapered, either smooth or with very fine lateral teeth (see character 32) ( Fig. 28F ). The dorsal margin of the mandibular arm is uniquely fused to the frontoclypeus (in all other ceratopogonids it articulates). The mandibular arm originates posterior to the posteroventral margin of the eye, a feature also evolved in a group of Sphaeromiini and in Pellucidomyia (see character 38). The hypopharynx is elongate, apically pointed and bare. In other Ceratopogonidae it is rounded or slightly pointed apically and nearly always has spicules or teeth (some Atrichopogon and all Forcipomyia also have a bare hypopharynx ( Glukhova 1981).

- Males have moderately elongate plume setae on flagellomeres 1–9, 11, and 12 (10 with shorter setae) or 1–13 (in at least some tropical species of E. ( Echinohelea )). If Echinohelea (Echinoideshelea) and Echinohelea (Echinohelea) are sister groups, which is likely based on degrees of fusion of the male gonocoxites ( Wirth 1994b), this reduction of plume setae on flagellomere 10 and their presence on flagellomeres 11 and 12 is unique in the family. Wirth (1994b) stated that male Echinohelea have female-like antennae but, although the plume setae are reduced in length in males, they are longer than those in females ( Wirth 1994b: Figs. 1 , 9 ).

- Wing with five or more stout, long costal setae basal the position of the arculus. This feature also is present in at least males of the more distantly related Yungahelea and Diaphanobezzia . Some Parabezzia have up to three stout, long setae.

- Males and females with an apodeme directed dorsolaterally from the closely approximated thoracic scutal apodemes ( Fig. 41D ). This feature is unique in the Culicomorpha.

- Male abdomen with abdominal tergites 4–8 progressively shorter, with 8 being very short, appearing as a thin band. This feature is unique in the Culicomorpha. In other Ceratopogonidae there is considerable variation in the relative lengths of tergites, generally with either 6–8 or just 7–8 being progressively shorter. In some Stilobezzia 4–8 are progressively shorter. In some, 7–8 are shorter than preceding tergites but of nearly equal size to each other. In some genera belonging to higher lineages, such as Heteromyia and Clinohelea , tergite 8 is very short but not as short as in Echinohelea .

- Male genitalia with lateral margin of segment 9 absent, with medial portion of segment 9 expanded posteriorly, abutting the bases of gonocoxites or surrounded by the ventrally fused basal portion of the gonocoxites. In Echinohelea (Echinohelea) the hypandrium is separated posteriorly by the ventrally fused gonocoxites, a derived feature of this subgenus and evidence that Echinohelea (Echinoideshelea) is the sister group of Echinohelea (Echinohelea) ( Wirth 1994b) . Some of the variation of the shape of the hypandrium is discussed under character 114.

Related to the above modifications, Echinohelea (Echinoideshelea) has the gonocoxites fused dorsally but not ventrally, while in Echinohelea (Echinohelea) they are fused both dorsally and ventrally. These too are virtually unique in the Culicomorpha. The single extant species of Meunierohelea has ventrally fused gonocoxites but in at least some fossil species they are separate ( Szadziewski 1988; Stebner et al. 2017). There is at least one markedly derived Atrichopogon ( A. spinosus Borkent & Picado ) which also has fused gonocoxites, also clearly independently derived ( Borkent & Picado 2004).

Figures

FIGURE 1. Head capsule of adult Culicoides pulicaris, in anterior view. A. Male. B. Female. (modified from Jobling 1928: Fig. 1)).

FIGURE 9. Phylogeny of the genera of Ceratopogonidae (final portion). Synapomorphy numbers not preceded by a letter are those of adults, “P- “indicates a pupal synapomorphy and “L- “a larval synapomorphy. Numbers which are underlined exhibit homoplasy and those in italics are reversals. Character state numbers coincide with the rectangle above them.

FIGURE 28. Apical portion of labrum of female Ceratopogonidae, in anterior view. A. Stilobezzia (Debenhamia) n. sp. B. Serromyia barberi. C. Monohelea ornata. D. Atyphohelea macroneura. E. Parabezzia huberti Grogan & Wirth. F. Echinohelea lanei. G. Hebetula tonnoiri (Lee). H. Hebetula bequaerti (Goetghebuer). I. Phaenobezzia fulvithorax.

FIGURE 41. Thorax or only dorsal portion of thoraces of Ceratopogonidae, in anterior view.A. Female Alluaudomyia needhami. B. Female Serromyia ledicola. C. Female Parabezzia bystraki. D. Female Echinohelea lanei. E. Male Clinohelea curriei. F. Female Palpomyia sp.