Ootheca variabilis ( Laboissière, 1920 ), Laboissiere, 1920

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 : 33-35

Ootheca variabilis ( Laboissière, 1920)

( Figs 27 , 46–50 )

= Ergana variabilis Laboissière, 1920: 132 .

= Ergana variabilis var. benardi Laboissière, 1920: 132 ; syn. nov.

Total length. 4.40–6.70 mm (mean: 5.48 mm; n = 25; Fig. 46 ).

Head. Dark brown to black. Antennae short, antennomeres broad, basal four to five antennomeres yellowish, others gradually becoming more brownish to black towards the apex; length ratios: second to third antennomere 0.60–0.88 (mean: 0.76); third to fourth antennomere 0.80–1.00 (mean: 0.88; Fig. 47 ). Maximal width of eye to minimal distance between eyes 0.44–0.64 (mean: 0.54).

Thorax. Pronotum: yellow to yellowish-brown, in 30 % of specimens examined with various darker brown patterns, usually with two brown spots on the disc ( Fig. 48 ), sometimes the darker brown colour covers the entire pronotum; finely punctuated, latero-basal impression distinct; width 1.75–2.45 mm (mean: 2.06 mm); length 0.95–1.40 mm (mean: 1.19 mm); pronotal width to length ratio 1.64–1.90 (mean: 1.74). Elytra yellowish- to reddish-brown with at least suture dark brown, but brown sutural colouration usually covers up to one third of the elytron and then outer elytral margins also dark brown to black for up to one quarter of the elytron width ( Fig. 48 ); punctuation irregular, deeper and coarser than that of distinctly depressed; length 3.30–4.95 mm (mean: 4.27 mm); maximal width of elytra together 2.20–3.60 mm (mean: 3.01 mm); maximal width of elytra together to length of elytron ratio 0.65–0.74 (mean: 0.71), slender. Scutellum, meso- and metathorax, and legs dark brown to black; third to fifth tarsomeres paler brownish colour on all legs, length ratio of basi-metatarsus to metatibia 0.18–0.25 (mean: 0.21).

Abdomen. Dark brown to black.

Male genitalia. Median lobe constricted in the middle, with short, rounded apex. Tectum consists of a pair of strongly outwardly curved tectorial spurs. Endophallus small, slender, with one pair of very small dorsal spines ( Fig. 49 ).

Diagnosis. Distinctive characters for this species include a completely dark brown to black head, legs and underside; short antennae with broad antennomeres; yellowish pronotum usually with darker brown discal spots and a distinct latero-basal pronotal impression; and yellowish elytra with a more or less broad dark brown to black suture. Ootheca ugandae sp. n. is most similar in colouration of the head, underside and legs, and also has a broad black elytral suture, but the outer elytral margins are always yellow and a submarginal longitudinal stripe is black; pronotum is either entirely yellowish-brown, or has darker brown medio-basal patches; elytra are much more coarsely punctuated, and more convexly rounded; third antennomere is much longer than the second (length ratio of second to third antennomere 0.55–0.67; O variabilis 0.60–0.88), and it is on average larger overall (total length 5.75–5.95 mm; O. variabilis 4.40–6.70 mm). Furthermore, O. julianae sp. n. is similar to O. variabilis in size and colouration, but the former has an entirely yellowish pronotum, yellow legs, and broad brown outer elytral margins and humeri. Since colour patterns are quite variable in most species of Ootheca the male genitalia should be checked in doubtful cases.

Distribution. Only known from the eastern shores of Lake Victoria to montane regions along the East African Rift Valley in Kenya ( Fig. 27 ).

Type material examined. Ergana variabilis : Lectotype: female, “Salt Marsh, Nyanza Province (B. E. A.) / G. B., Janv. 1913 / Type / Ergana variabilis m. V. Laboissière - Det./ AfriGa specimen ID 890, specimen data documented 20.IX.2004 ”( MNHN; Fig. 50 ). Type locality: Kenya, 0°30’S / 34°30’E. Paralectotypes (including paralectotypes of E. variabilis var. benardi which cannot be clearly separated from the nominate taxon): 8 ex., same data as lectotype (1 ex. BMNH, 6 ex. MNHN 1 ex. ZMUH); 8 ex., “Amala River, Sotik (B. E. A.) / G. B., Janv. 1913”, 0°47’S / 35°21’E (4 ex. MNHN, 4 ex. ZMUH); 1 ex., “Guasso Nyro (sud), Sotik (B. E. A.) / G. B., Janv. 1913” (1 ex. ZMUH); 4 ex., “Onjoro O Nyro, Masai (B. E. A.) / G. B., Janv. 1913”, 1°45’S / 36°00’E (3 ex., MNHN, 1 ex. ZMUH); 3 ex., “Lemek Valley, Nyanza Province (B. E. A.) / G. B., Janv. 1913”, 1°06'S / 35°23'E (2 ex. MNHN, 1 ex. ZMUH). This designation. Type locality: Kenya, Western Province, 0°46’S / 35°07’E. Laboissière mentioned several specimens in his original publication from three locations and few specimens of the type series carry labels with “ type ” used by the author, thus a lectotype is herein designated to fix the name to a single specimen.

Additional material examined. Kenya: 1 ex., Kisii District, S. Kavirondo, 5000 ft, 0°45’S / 34°25’E, V.1911, S. A. Neave ( BMHN).

Figures

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

FIGURE 50. Lectotype of Ergana variabilis Laboissière, 1920, a. specimen with labels, b. close-up detail of specimen.

FIGURES 46 – 49. Ootheca variabilis (Laboissière, 1920). 46. Habitus, dorsal view; 47. Antennomeres 1 – 4 of two different males and two different females; 48. Colour pattern of some specimens; 49. Median lobe: dorsal (left), lateral (right).