Gymnochiromyia Hendel, 1933

Ebejer, Martin J., 2009, A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera, African Invertebrates 50 (2), pp. 321-321 : 335-337

Genus Gymnochiromyia Hendel, 1933

Gymnochiromyia: Hendel 1933: 43 ; Ebejer 2008 b: 81.

Type species: Peletophila minima Becker, 1904: 133 (= Anthophilina flavella Zetterstedt, 1848 ), by original designation.

This genus was recently reviewed (Ebejer 2008 b) and 14 new species were described, bringing to 15 the total number of confirmed species from the Afrotropical Region.

Diagnosis: Oval eyes lying horizontal or oblique; fr protruding beyond anterior eye margin and above antennae, visible in profile to greater or lesser extent; setae and setulae on scut absent except for usual basal and subapical pairs; pra and strong post ia setae absent; apicoventral seta on mid tibia absent; habitus of most species appearing more slender and less setulose than Oroschyromya and Notiochyromya , with which genera Gymnochiromyia could be confused.

Distribution: Afrotropical ( Fig. 68 ), Holarctic.

Bionomics: Species of Gymnochiromyia appear to prefer vegetated dunes and drier, warmer areas within a generally temperate climatic region. In Europe, for example, at least two species, namely G. homobifida Carles-Tolrá, 2001 and G. inermis ( Collin, 1933) , exhibit an affinity for open oak woodland (Ebejer, pers. observ.).

Genus Notiochyromya gen. n.

Type species: Notiochyromya tripunctata sp. n., here designated.

Etymology: From Greek notios (southern), referring to the occurrence of the majority of species of the genus south of the equator, and Chyromya . Gender feminine.

Diagnosis: fr measured at level of anterior oc narrower than 1/3 width of head, with margins strongly convergent towards lunule, inclination of fr more toward vertical than horizontal, thus maximum length of head when seen in profile closer to lower eye margin than upper, ocp flat, pra seta present, post ia and prsut dc setae absent; scut usually with additional marginal or discal setae (not setulae) or both; a short apicoventral seta usually present on mid tibia; head usually narrower than thorax; ep relatively small in comparison to remainder of abdomen (similar to Somatiosoma , but in contrast to Oroschyromya and Gymnochiromyia ); thorax robust, covered with dense fine setulae over whole of scutum; strong prscut acrs (often 4 setae in one transverse row), dc, post ia and pa setae close to scut suture and usually brown or black; tg frequently with matt or shiny brown or black spots.

The autapomorphies that characterize this genus are: a smaller head, longer in lower half than above, always higher than long, narrow fr strongly sloping such that it is inclined much more towards the vertical than the horizontal; a distinct pra seta, broad prg and large ej apd. In other respects, the habitus of the fly and the appearance of the scutum are similar to Somatiosoma .

Description:

Head: Higher than long, also a little broader than long; ocp flat in profile or only slightly convex; fr narrow at vertex, not more than 0.3 width of head, and eyes strongly convergent; orb plate distinct throughout. Chaetotaxy: 3 strong orb, 2 hind orb reclinate, anterior inclinate, pvt distinct and crossed, 1 vti and 1 vte, postocular setulae distinct, generally short, more or less in one row, lower postgenal seta present or absent; mouthparts normal, palp rather broad, almost disc-shaped; antenna with third segment round and arista bare.

Thorax: Broader than head and robust relative to remainder of fly. Chaetotaxy: prpl setula absent, 1 strong postsutural dc, often with 1 shorter seta anterior to this, acrs not differentiated from other scutal setulae, between dc lines in 8–12 rows with 2–4 distinct prscut; 1–2 pprn, 1 posthu, 2 ntpl, 1 distinct pra behind transverse scutal suture; 1 sa and 1 long pa, 1 short post ia, 2–4 pairs of marginal scut setae; sometimes with setulae on disc; anepisternum with 1 strong seta directed backwards at middle of posterior margin, katepisternum with 1 strong seta at upper posterior corner, each with a variable number of short setulae in front; tuft of numerous, fine, long setulae at ventral aspect of katepisternum.

Wing: Hyaline, R 4+5 and M 1+2 parallel towards wing apex or very slightly convergent at tip; discal cell wide beyond middle, about 2–3 times as wide as anterior basal cell; costal setulae short with variable number of stouter and darker setulae along anterior edge; costa, just beyond hu crossvein, narrowed but without distinct break. Haltere pale.

Legs: Yellow with fine setulae scattered on all pairs, in addition, a few longer setae usually present posterodorsally on fore femur; mid tibial apicoventral seta present or absent, but not longer than diameter of tibia at apex; femora, especially middle and posterior, slightly dilated; hind trochanter and tarsomeres not modified.

Abdomen: More or less compressed dorsoventrally; usually short but densely setulose, with longer setae along hind margin and lateral aspect of tg especially towards apex of abdomen; 6 visible tg in male and 7 in female, tg 6 normal; st sclerotized in both sexes, pollinose except for central part of st 2; pregenital st variably modified; female tg frequently with large brown to black shiny spots laterally.

Postabdomen: ep not usually as large as in other Chyromyinae ; relatively large posteroventrally directed opening; cerc small, separated and poorly sclerotized with fine short setulae; hyp distinct and broad; ph apd broad and free from hyp for a short distance (cf. Gymnochiromyia ); ej apd very large and well sclerotized; distiph complex as usual for the family, with sclerotized and membranous components; prg rather broad and flattened and variably sclerotized; psg of various forms in the species described.

Distribution: Afrotropical ( Fig. 66 ); Pantropical.

Ecology: Species of Notiochyromya seem to prefer hot and wet (at least seasonally) environments. The genus is widespread in the tropics and subtropics of the Old World as well as the New World (New World species are undescribed), both on the continents and on islands. To date, most species are known from the Southern Hemisphere. Too little is known about their habits to make deductions on preference for vegetation cover, but by inference from data labels most appear to inhabit forests, or at least the edges of them. This includes forests encroaching on the seashore. N. sexspinosa was collected from entrances to caves in Nigeria (J.C. Deeming, pers. comm.).

Figures

Fig. 68. Distribution of Somatiosoma Frey () and Gymnochiromyia Hendel (•) in Africa.

Fig. 66. Distribution of Notiochyromya gen. n.