Sarangesa maculata ( Mabille 1891 )

COCK, MATTHEW J. W. & CONGDON, T. COLIN E., 2011, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera) principally from Kenya. Part 3. Pyrginae: Celaenorrhinini, Zootaxa 3033 (1), pp. 1-67 : 58-59

Sarangesa maculata ( Mabille 1891) (Figures 61–63)

This species was described from Mozambique and its range extends north to Kenya, and west to Cameroon ( Evans 1937, Larsen 2005). The large hyaline spot in space 2 combined with the white UNH makes this species unmistakable. I have found this is a rather uncommon species of rain forests, whereas Larsen (1991) suggests it is a fairly common species, widespread in Kenya, mainly found in savannah country. Sevastopulo (1974) records it as fairly common in the Makardara Forest, Shimba Hills, and I have found it in the nearby Marere Forest.

Adult behaviour

I have seen a male feeding at a bird dropping in Kakamega Forest (18 Dec 1990). In my experience it seems to frequent open patches and edges of forests, as well as flying around trees and bushes in savannah country according to Larsen (1991) .

Food plants

Sevastopulo (unpublished) reared a caterpillar collected on Asystasia sp. from Kwale. The resultant adult was a crippled female with a white UNS – either S. maculata or Eagris nottoana . Since Sarangesa spp. are only known to feed on Acanthaceae , and no Eagris spp. are known to use this family, I conclude (as Sevastopulo did) that the caterpillar he described is almost certainly S. maculata . TCEC raised this species from A. gangetica (TCEC#380) in Minziro forest, north–western Tanzania, in 1994. I reared two caterpillars from A. gangetica at Diani Beach (20 Aug 1995) identical to those of Sevastopulo. Heath et al. (2002) give the food plant as Asystasia gangetica in their account of the butterflies of Zambia, but this is probably not an original observation.

Leaf shelters

The early shelters are triangular two-cut shelters and similar to others of this genus. The larger caterpillars use a whole leaf, folding it over upwards and joining the edges with silk; they may also feed to some extent on the same leaf. Sevastopulos's pupa was formed between two spun-together leaves.

Caterpillar

According to Sevastopulo (unpublished) the early instars are deep pink, with an increasingly strong green tint, and a black head. In the final instar the head is black, heart-shaped, covered with short, pale setae; body dark, translucent, shiny greenish grey; a broad lateral stripe more tinged with green with a white line below due to trachea visible through cuticle; ventral and sublateral area yellowish green; legs black; prolegs yellowish green with an external black spot; late in the instar the caterpillar is fairly dark green with a darker dorsal line, a broad, whitish subdorsal stripe and a fine yellow spiracular line (Sevastopulo unpublished, with slight modifications from my own observations). Examination of the head capsules show that those of the last two instars are weakly rugose, black and shiny, covered with frond-like erect pale setae; that of the penultimate instar measured 2.05 x 1.90 mm, while that of the final instar measured 2.85 x 2.78 mm wide x high. The apparently smooth body is actually covered with very short, pale, stalked stellate setae, although these are not visible without magnification, they can be seen as dots on the body in Figure 62.2 .

Pupa

The 16 mm pupa is whitish blue-green, the abdomen paler, and covered with long, pale, erect setae except on appendages; the proboscis extends 3 mm beyond the wing cases, almost to the cremaster; cremaster back above, the black marking divided anteriorly; head with an olive brown to black frontal mark extending onto the collar,

consisting of four conjoined spots above and three larger conjoined spots below; T1 spiracle large, mat black or dark brown and strongly protuberant; other spiracles light brown (Sevastopulo unpublished and author’s description of 95/104A). Pupation lasted nine days (male 95/104B) and 11 days (female 95/104A).

Figures

FIGURE 62. Final instar caterpillar of Sarangesa maculata, collected as n–1 caterpillar on Asystasia gangetica, Diani Beach, 22 Aug 1995; moulted to final instar 26 Aug; photographed 1 Sep, 23 mm; pupated 8 Sep; 95/104B. 1, dorsolateral view. 2, detail of head, anterior view.