Gymnosophistis Meyrick, 1934

Bartsch, Daniel, 2018, Revision of Gymnosophistis Meyrick, 1934 (Lepidoptera: Sesiidae) from East Africa with description of a new species, Zootaxa 4532 (1), pp. 145-150 : 146-148

Gymnosophistis Meyrick, 1934

Type species: Gymnosophistis thyrsodoxa Meyrick, 1934: 454 , by monotypy.

References: Naumann 1971: 17; Fletcher & Nye 1982: 72; Heppner & Duckworth 1981: 43; Pühringer & Kallies 2004: 44.

Redescription. Alar expanse 20–25 mm.

Head: haustellum well developed; labial palpus strongly upturned, covering frons, tip between bases of antennae, second palpomere somewhat longer than first and third; dorsally smooth scaled, ventrally rough, somewhat appressed, laterally protruding; width of frons about twice the diameter of an eye; scales of frons and vertex long, hair-like; pericephalic scales dorsally long, hair-like, laterally short; antennae strikingly short, about half as long as forewing, strongly clavate, flagellum proximally somewhat serrate, ciliate, with proximal ciliae longest, club without ciliae.

Thorax: strong, densely covered with hair-like scales. Legs strong; mid- and hind tibia as well as first tarsomere of hind leg tufted with rough long, hair-like scales; all spur pairs with lateral spurs somewhat less than half as long as mesal ones. Wings: largely transparent; apical area absent; margins very narrow, except for broad costal margin; discal spot of forewing extremely narrow; discal spot of hind wing absent; venation in forewing with R1 to R3 closely approximated, R4 and R5 stalked to more than half length; all veins from stalk of R4/R5 to M3 arise almost equally spaced from cross vein; CuA1 and CuA2 coincident; hindwing venation typical of Sesiini with veins M3 and CuA1 stalked.

Abdomen: rather short and broad, spindle-shaped, first tergites densely, other tergites scarcely covered with hair-like scales, anal tuft well developed.

Females unknown.

Male genitalia. ( Figs. 7–8 ). Tegumen broad; gnathos small, slightly asymmetric, distally pointed; uncus narrow, ventro-lateral margins densely covered with long, hair- to bristle-like, proximad pointing setae, dorsally seamlessly fused, ventrally connected to tegumen by a membrane; valva broad, ovoid to rectangular, without crista sacculi or other raised structures, dorso-medially and distally densely covered with proximad pointing, bristle-like, apically mostly bifurcate setae; juxta narrow, posteriorly wide protruding; vinculum forming a short to moderately long saccus; phallus long and slender, almost straight, longer than valva; coecum penis present, short, slightly curved, proximally rounded; vesica basally with numerous teeth or thorns.

Diagnosis. Medium sized, powerfully built clearwing moths. The fusion of forewing veins CuA1 and CuA2 is here considered a synapomorphy of the genus; it is unique within the Sesiinae . Antennae extraordinarily short, that of the male clavate, ciliate, rather than pectinate or simple as in most other African Sesiini . Alonina Walker, 1856 is most probably the sister group of Gymnosophistis . Both genera have a functional haustellum; very similar shape and covering with scales of the labial palpus; coverage of large parts of the body and legs with hair-like scales; in the male genitalia similar shape of tegumen, uncus, valva, juxta and phallus. Most importantly, both genera display a very similar bristle-like shape and proximad pointing arrangement of setae of the uncus and dense, bristle-like, medially and distally located proximad pointing, setae of the valva. Both genera also have clavate and ciliate antennae; however, they are distinctly longer and narrower in Alonina . Another clear difference of the two genera, beside the fused forewing veins, is the shape of the gnathos, which is symmetric in all species of Alonina , with two short, down curved hooks (asymmetric, a single distally slightly pointed protrusion in Gymnosophistis ). Superficially similar species of Felderiola and Monopetalotaxis differ by the lack of a functional haustellum, males moreover by the simple, thorn-like setae of the valva.

Heppner & Duckworth (1981) list Gymnosophistis under “genera unassigned to subfamily”; Pühringer & Kallies (2004) placed it in “ Sesiinae genera unassigned to tribe”. It is here placed in Sesiini .

Distribution. So far only known from Kenya, East Africa.

Biology and host plant(s) are unknown.

Figures

FIGURES 7–8. Male genitalia of Gymnosophistis Meyrick, 1934: 7. G. thyrsodoxa Meyrick, 1934, lectotype; 8. G. staudei sp. nov., paratype. Scales 1 mm.