Ootheca chapuisi ( Jacoby, 1899 )

Kortenhaus, Sabine & Wagner, Thomas, 2010, Revision of Ootheca Chevrolat, 1837 from tropical Africa — redescriptions, descriptions of new species and identification key (Coleoptera: Chrysomelidae, Galerucinae), Zootaxa 2659, pp. 1-52 : 18-21

Ootheca chapuisi ( Jacoby, 1899)

( Figs 24–28 )

Ergana chapuisi Jacoby, 1899: 366 .

Total length. 3.64–5.04 mm (mean: 4.19 mm, n = 10; Fig. 24 ).

Head. Yellowish- to reddish-brown. Antennae slightly paler, usually yellow basally, becoming darker brown from the fifth antennomere towards the apex; length ratio of second to third antennomere 0.60–0.91 (mean: 0.77); third to fourth antennomere 0.79–1.00 (mean: 0.93; Fig. 25 ). Maximal width of eye to minimal distance between eyes ratio 0.50–0.57 (mean: 0.53).

Thorax. Prothorax yellowish- to reddish-brown. Pronotum finely punctuated, latero-basal pronotal impression indistinct or lacking; width 1.52–2.00 mm (mean: 1.72 mm); length 0.96–1.28 mm (mean: 1.07 mm); slender, width to length ratio 1.50–1.68 (mean: 1.60). Elytra black, rarely with insignificant metallic blueish sheen, outer margin and epipleura sometimes lighter reddish-brown; much more coarsely punctuated than pronotum, the sutural punctures seriate giving the median third of the elytra a striped appearance; length 2.80–3.80 mm (mean: 3.26 mm), elytra nearly parallel-sided and slender, maximal width of elytra together 2.24–3.04 mm (mean: 2.64 mm); maximal width of elytra together to length of elytron ratio 0.72–0.86 (mean: 0.81). Scutellum reddish-brown to black. Meso- and metathorax dark brown. Legs dark brown to black, femoral apex, tibial base and three distal tarsomeres paler brownish-red; length ratio of basimetatarsus to metatibia 0.21–0.27 (mean: 0.22).

Abdomen. Reddish-brown, in contrast with much darker metasternum.

Male genitalia. The median lobe curved ventrally, becoming flatter towards non-incisedapex,. Tectum consists of two long, slender spurs, which nearly reach the apex of the median lobe, their tips crossing in the distal third and ventrally curved. Endophallus with two very slender dorsally curved spines. Basal part of endophallus short, trapezoidal in dorsal view ( Fig. 26 ).

Diagnosis. Ootheca chapuisi is the smallest species of this group and can be effectively distinguished from most other species purely by size, the coarse and partly seriate elytral punctuation, and the contrast between the dark brown metasternum to the reddish-brown abdomen. Only O. frontalis also displays seriate elytral punctuation, but is larger (total length 4.70–5.95 mm; O. chapuisi 3.64–5.04 mm). Males longer than 4.50 mm should be identified by genitalic dissection. Of similar size is O. julianae sp. n. that has brownishyellow elytra, usually with darker brown sutural and outer margins, and much finer punctuation. Some specimens of O. kibonotensis are of similar size and colouration as O. chapuisi , but posses a unicolourous, reddish-brown underside and a much finer elytral punctuation.

Distribution. Only known from some sites in south-eastern Democratic Republic of Congo along the western slopes of the Albertine Rift ( Fig. 27 ).

Type material examined. Lectotype: female “Musée du Congo Moliro (J. Duvivier) Coll. Clavareau / Moliro J. Duvivier / Ergana Chapuisi Type Jac. / Type / AfriGa Specimen ID 883, specimen data documented 1.VI.2004 ” ( MRAC; Fig. 28 ). This designation. Type locality: Congo, 8°13’S / 30°34’E.

Paralectotypes: 6 ex., “Moliro (J. Duvivier), Coll. Clavareau / Moliro, J. Duvivier” (2 ex. BMNH, 4 ex. MRAC). Jacoby mentioned two specimens in his original publication, but there are seven specimens from the type locality (all with the same label) available. A lectotype is herein designated to fix the name to a single specimen.

Additional material. Congo (Democratic Republic): 2 ex., Kankunda s. affl. r. dr. Lufira (1300 m), 6°38’S / 25°55’E, XI.1947, Miss. G. F. de Witte ( MRAC); 2 ex., R. Kateko s. affl. Lufira (960 m), XII.1947, Miss. G. F. de Witte ( MRAC).

Figures

FIGURE 27. Distribution of Ootheca chapuisi, O. variabilis and O. kibonotensis.

FIGURE 28. Lectotype of Ergana chapuisi Jacoby, 1899, a. specimen with labels, b. close-up detail of specimen.

FIGURES 24 – 26. Ootheca chapuisi (Jacoby, 1899). 24. Habitus, dorsal view; 25. Antennomeres 1 – 4 of two different males and two different females; 26. Median lobe: dorsal (left), lateral (right).