Microsesia nana, Bartsch, Daniel, 2015

Bartsch, Daniel, 2015, New taxa of southern African Sesiini (Lepidoptera: Sesiidae), Zootaxa 3956 (3), pp. 428-436 : 429-431

Microsesia nana new sp.

Figs. 1–7 , 15

Specimens examined. Holotype. ♂ ( Figs. 1–2 ) South Africa, East London, Beacon Bay, 10 Nov 1980, N.J. Duke leg. (gen-prep Bartsch 2014-02, Fig. 5 ) (TMPS). Paratypes (5). 1 ♀ ( Figs 3–4 ) in copula with holotype (gen-prep Bartsch 2014-01, Fig 7 ); 1 ♂, Swaziland, Mbabane, Miden Falls, 19 Nov 1991, N.J. Duke leg. (gen-prep Bartsch 2012-02, Fig. 6 ); 1 ♂, South Africa, Zoutpansberg, Tshakoma, Nov 1931, G. van Son leg.; 1 ♀, Stellenbosch, Jonkershoek Reserve, 7 Oct 1931, H.K. Munroe (TMPS); 1 ♂, Capetown, Kirstenbosch, 13 Oct–7 Nov 1958, Lindner leg. (SMNS).

Description. ( Figs. 1–4 ). Head: Almost completely brownish grey with strong silvery gloss; labial palpus white, terminal palpomere ventrally and laterally brownish grey; lower part of frons at adjacent to the eyes and lateral part of pericephalic scales white; antenna 3.5 mm; Thorax: Wingspan 11 mm, forewing length 5.5 mm; brownish grey with silvery gloss; hindtibia and tarsus internally and hindtibia, except for brownish grey distal part, externally white; forewing opaque, brownish grey, subdistally with some whitish scales; hindwing hyaline with broad grey semitransparent margins; fringes grey, white at hindwing dorsum. Abdomen: Brownish grey with silvery gloss. Genitalia as described for genus.

Variation. The whitish scales of the forewings are lost in older specimens. The genitalia of the two dissected specimens exhibit some variation in the shape of the valva, with the paratype showing a less concave dorsal margin and longer dorso-distal protrusion, denser, but less extensive field of setae of the valva as well as a larger number of distal teeth of the phallus than the holotype. However, these specimens are considered conspecific as no further differences were found.

Diagnosis. Microsesia nana is a very small, unmistakable species without distinct sexual dimorphism. It is superficially somewhat similar to some members of Tinthiini and Paraglosseciini (Tinthiinae) . However, the Tinthiini of Africa south of the Sahara (reviewed by Kallies, 2000) have a very different appearance, and the tribe Paraglosseciini is not represented in Africa. Importantly, all Tinthiinae species can be easily distinguished by the lack of an apical tuft of setae on the antenna, which is an autapomorphy of the Sesiinae , and by the distinctly different wing venation and genitalia.

Etymology. Ancient Greek nannos (= dwarf).

Figures

FIGURES 1 – 7. Specimens and genitalia structures of Microsesia nana new sp. 1 – 2. Adult male holotype. 3 – 4. Adult female paratype, South Africa, East London, Beacon Bay, captured in copula with holotype. 5. Genitalia of male holotype. 6. Genitalia of male paratype, Swaziland, Mbabane, Miden Falls. 7. Genitalia of female paratype, South Africa, East London, Beacon Bay. Scale bars 10 mm.

FIGURES 15 – 16. Wing venation. 15. Microsesia nana, new sp. 16. Coccophila pythes (Druce, 1899).