Ophirodexia semirufa ( van der Wulp, 1891 ) de Santis, 2021

de Santis, Marcelo Domingos, 2021, A review of Ophirodexia Townsend, 1911 (Diptera: Tachinidae), Journal of Natural History 55 (3 - 4), pp. 151-161 : 157-158

Ophirodexia semirufa ( van der Wulp, 1891) comb. nov.

( Figure 2 )

Leptoda semirufa van der Wulp, 1891: 250 . Type locality: Yucatán, Mexico .

Zelia semirufa ( van der Wulp, 1891) . Guimarães, 1977: 103 (catalogue); O’Hara et al. 2020: 85 (checklist of world Tachinidae ).

Type material examined. Holotype ♂ ( NHM-UK): ‘Holo-/type’‘ ♀ ’; ‘N. Yucatan,/Gaumer.’; ‘ B.C.A. Dipt. II/ Leptoda /semirufa,/v.d.W.’; ‘Centra America./Pres. By/ F.D. Godman. / O. Salvin. /1903-172.’; ‘ NHMUK 013933627 ’.

Redescription. Body length: 12.0 mm.

Colouration. Frontal vitta and ocellar triangle dark brown to black. Fronto orbital plate and parafacial with pale golden pruinosity. Occiput silvery pruinose with long and golden setulae. Postpedicel orange, but posterior margin brownish black. Palpus light yellow to orange. Thorax brown to dark brown with pale golden to greyish pruinosity; in presutural region with four dark vittae, the two inner vittae are thinner than the outer, in postsutural region with five dark vittae, only the median vitta reaching the hind margin, the outer vittae twice as long as the submedian pair. Scutellum silvery pruinose. Wing hyaline. Calypter hyaline. Halter yellow-tawny. Posterior spiracle light yellow. Legs brownish black, but femur silver pruinose. Claws brown, pulvilli yellow. Abdomen dark yellow, with uninterrupted median brown longitudinal vitta on syntergite 1 + 2 to tergite 4; posterior margin of tergite 4 broadly dark, and more narrowly so on tergite 3, both these tergites with a band of silver pruinosity on anterior half, ground colour of tergite 5 mostly tawny yellow, almost entirely covered with silver pruinosity.

Head. ( Figure 2 (a,b)). Ocellar seta weak. Frontal vitta at its widest point ca. as wide as the vertex in dorsal view. Frontal vitta at its narrowest point smaller than the width of the ocellar triangle. Inner vertical setae well developed and long, outer vertical seta shorter, about 1/4 the length of inner. Fronto-orbital plate with 12–13 pairs of proclinate setae; narrower than frontal vitta and parafacial. Postocellar proclinate. Width of parafacial measured between inner margin of compound eye and antennal insertion is 0.8–0.9× the width of gena in lateral view. Postpedicel slender, 2× the combined length of scape and pedicel; ventral cilia longer than the dorsal, longest cilia ca. 4× basal width of arista. Facial ridge with 3–4 setulae on lower third. Lower facial margin not protruding, invisible in profile. Vibrissa long, inserted at the level of lower facial margin. Prementum about 0.8× the length of palpus. Labellum narrow, about 0.3× the prementum.

Thorax. ( Figure 2 (a,c)). Acrostichals 2 + 3. Dorsocentral 4 + 4. Intra-alar 2 + 4; intrapostalar absent. Supra-alar 2 + 3. Postpronotal lobe with 3 setae arranged in a straight line. Anepisternum with 6 strong setae and with 2 upwardly directed setulae anteriorly. Scutellum with 1 basal, 1 lateral, 1 apical and 1 discal pair of setae. Katepisternum with 3 setae. Anepimerum with 1 long seta. Notopleuron with 2 equal-sized setae. Postalar callus with 2 setae. Propleuron and prosternum bare. Anatergite bare. Posterior spiracle with posterior lappet larger than anterior. Katepimeron sparsely setulose.

Wing. ( Figure 2 (a,c)). Base of R dorsally and ventrally setulose. M vein bent forward to R 4+5, forming an angle slightly smaller than 90°, and convex after bend.

Legs. Fore coxa with many setae anteriorly; fore femur with dorsal and posteroventral rows of setae; fore tibia with row of anterodorsal setae, 1 posteroventral seta on median third, 3 preapicals, 2 anterior and 1 posteroventral. Mid femur 2 anteroventral setae on anterior half; 2 anterodorsal setae on apical third; mid tibia 1 posterodorsal seta on distal half; 2 anteroventral setae on posterior half. Hind femur with a row of anteroventral and anterodorsal setae, 3 posteroventral setae on apical median half; hind tibia with 3 anterodorsal and 3 posterodorsal setae on median half; 2 anteroventral setae on median half. Mid tibia with 2 posterodrosal setae on median third, 5 preapicals, 2 anterodorsals and 3 posteroventral. Claws straight with the tip curved, shorter than 5th tarsomere.

Abdomen. ( Figure 2 (a,c)). Syntergite 1 + 2 and tergite 3 each with 1 pair of median and 1 pair of lateral marginals, tergites 4 and 5 each with complete row of marginals, tergites 3 to 5 each with 2–3 discals.

Terminalia . Not dissected; only male holotype was available.

Female. Unknown.

Biology. Unknown.

Note. van der Wulp (1891) was uncertain of the sex of this species and preferred to list it as undetermined in his description. However, the holotype presents a label indicating that this specimen is a female (‘ ♀ ’). A detailed morphological analysis makes it clear, however, from the visible terminalia, that this a male and not a female.

Figures

Figure 2. Ophirodexia semirufa (van der Wulp), holotype ♂. (a) Dorsal habitus. (b) Head, frontal view. (c) Lateral habitus. (d) Labels.