Ptenidium Erichson, 1845

Darby, Michael, 2014, Studies of Madagascan Ptiliidae (Coleoptera) 2: The genus Ptenidium including three new species, Zootaxa 3793 (3), pp. 350-360 : 352-356

Ptenidium Erichson, 1845

Erichson (1845)

Diagnosis. Integument strongly sclerotised and shining, appearing polished, colouration reddish brown to black, surface with or without pubescence. Antennae 11 jointed with two basal antennomeres much enlarged and antennomeres 10 and 11 forming a club. Pronotum rounded at the sides sometimes with a seta-bearing fovea situated medially, generally with four clearly defined seta bearing foveae near the base and two further, often less distinct, seta bearing foveae placed on the front of the disc; rarely punctate; scutellum ornamented along the basal groove with foveae and carinae; elytra with/without a small humeral carina projecting rearwards; epipleura separated by a well-developed carina; and with the ventral posterior margin bearing dense pubescence extending forwards along the lateral margins. Wings of the usual ptiliid form. Proventrum with a central process between the procoxae, extending rearwards. Mesoventrum with sharp projecting anterior angles and a raised area anterior to the mesocoxae meeting with a forwardly projected process of the metaventrum shaped to take the proventral process; collar not extending onto shoulders except sometimes as a narrow border and projecting rearwards medially to form a +/- point; posterior margin extending forwards at sides to obtuse angle with lateral margins, with/without a series of regular/irregular indentations; metaventrum not toothed adjacent to metacoxae which are separated by approximately a metacoxal diameter; abdomen completely covered by the elytra, tergites 9 and 10 (pygidium) separate, not fused together, the apex with a series of teeth; remaining ventrites with either a straight or scalloped posterior margin; aedeagus long and simple, the apex cleft, situated medially in the abdomen, spermatheca of variable form.

Ptenidium (Gillmeisterium) azafady sp. n. ( Figs.1 , 4, 9, 14, 17, 20, 23, 24, 29, 33)

Habitus Fig. 1 . Length 0.84–0.98 mm. Colour dark brown, antennae and legs yellow. Antennae show some variation in length and thickness of antennomeres 3–4 Fig.20 . Mentum with evenly rounded anterior margin and broad base Fig. 17 . Width across eyes 0.30–0.33 mm. Pronotum 0.25–0.29 mm long, 0.41–0.44 mm wide, with scattered, very short pubescence, lateral margins evenly rounded (a very slight indentation is sometimes apparent at the junction with the marginal foveae) Fig. 4, the two anterior and four basal foveae of approximately the same size. Elytra 0.55–0.62 mm long, 0.46–0.51 mm wide, with scattered small and large foveae, the latter forming distinct rows, a small carina projecting backwards on the humeral border and dense patches of hairs on the underside at the posterior margin Fig. 39 . Proventral process broadest at base, central raised portion widest in middle where it is slightly flattened Fig. 14 . Lateral arms of meso/metaventral suture with indentations near mesocoxae as Fig. 38 . Abdominal ventrites with a scalloped edge as Fig. 37 . Pygidium with 4–6 teeth Fig. 33 .

Female: larger than male. Spermatheca shows considerable variation in the placement and distribution of coils forming the duct Figs. 23, 24 .

Male: smaller than female and appearing more rounded and polished. Aedeagus Fig. 29 .

Etymology. This epithet is taken from the name of the charity which works to tackle Madagascan poverty and suffering, and to protect unique environments.

Remarks. I have tried hard to make two species out of this material based in particular on the spermathecal and antennal variation but finally ruled this out on the basis of the sexual differences. The evenly rounded anterior margins of the pronotum without obvious foveae will quickly distinguish it from lambdai and tanalai .

Type data. Holotype: ♀, Montagne d’Ambre, sifting, 1100m, 30.x.2010, P. Banar ( BMNH). Paratypes: 77 specimens, same data as holotype ( BMNH).

Figures

FIGURES 1 – 3. Ptenidium spp. habitus. 1, P. azafady; 2, P. lambdai; 3, P. tanalai. 4 – 6. Lateral border of the pronotum. 4, P. azafady x 985; 5, P. lambdai x 1180; 6, P. tanalai x 935. 7 – 11. Scutellum. 7, P. reitteri x 850; 8, P. pusillum x 600; 9, P. azafady x 555; 10 – 11, P. lambdai x 1120.

FIGURES 17 – 22. 17 – 19. Ptenidium spp. mentum. 17, P. azafady x 1160; 18, P. lambdai x 1560; 19, P. tanalai x 1600. 20 – 22. Ptenidium spp. antennomeres 3 – 11. 20, P. azafady; 21, P. lambdai; 23, P. tanalai.

FIGURES 36 – 39. Ptenidium tanalai. 36, abdominal tergites showing spines on plates around wing folding spicule patches x 1560; 37, abdominal ventrites showing scalloped edges x 1500; 38, meso / metaventral suture showing wavy edge. x 715; 39, hairs on the underside of the posterior margin of the elytra x 1920.

FIGURES 12 – 16. Ptenidium spp. proventral process. 12, P. pusillum x 1480; 13, P. reitteri x 2320; 14, P. azafady x 1580; 15, P. lambdai x 1380; 16, P. tanalai x 890.

FIGURES 29 – 35. 29 – 31. Ptenidium spp. aedeagus. 29, P. azafady; 30, P. lambdai; 31, P. tanalai. 32. Ptenidium lambdai male 7 th ventrite. 33 – 35. Ptenidium spp. pygidium teeth. 33, P. azafady x 1240; 34, P. lambdai x 1400; 35, P. tanalai x 2000.

FIGURES 23 – 28. Ptenidium spp. spermatheca. 23 – 24, P. azafady; 25 – 26, P. lambdai; 27 – 28, P. tanalai (28 A viewed from a little above and 28 B a little below).