Sarangesa haplopa Swinhoe 1907

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 : 55-57

Sarangesa haplopa Swinhoe 1907 (Figures 57–60)

This species was described from the East Ruwenzori Mountains, and it is restricted to East Africa. In Kenya, it is commonest in the forests of western Kenya, but is quite widespread, extending as far East as Lake Nakuru. It is mostly a species of forests, but I once found it commonly (6–7 Aug 1990) in the early morning in the overgrown grounds of the Kisii Hotel (unfortunately this area was considerably tidied a year or two later) .

Adult behaviour

The behaviour is similar to that of Celaenorrhinus spp. , the adults come readily to flowers such as Justicia flava and Vernonia sp. and rest on vegetation with their wings spread. The flight is perhaps not as powerful as that of Celaenorrhinus spp. , but their dark colour makes them more difficult to follow in flight.

I observed oviposition once in Kakamega Forest (6 Jan 1989, 89/3). The female was hovering around some J. flava which had grown up on a bush to a height of about 2 m. She alighted briefly on the upper surface of several leaves and appeared to test them by touching them with her abdomen tip. Two young leaves were rejected before an egg was laid on one of the mature leaves, and the female then flew away .

Food plants

The food plants are Acanthaceae , including Justicia flava (four collections) and Hypoestes triflora (one collection). Larsen (1991) reports Justicia based on my observations. Caterpillars, probably of this species, were not able to transfer from J. flava to Hypoestes aristata , and I was not able to rear this species through until I had J. flava growing in Nairobi.

Ovum

When newly laid the ovum is yellow, but soon turns dark orange. Similarly to other members of the family it is ribbed with 14–16 ribs. An ovum laid in Kakamega Forest (89/3) hatched after nine days under Nairobi conditions. Ova are laid on the leaf lamina upper surface (89/5, 90/88).

Leaf shelters

Caterpillar

This species has five instars. The newly hatched caterpillar is orange with a brown head, smooth, shiny, with a few short, pale setae. In instar 2 the head is dark brown, weakly reticulated with ridges; especially dorsally and laterally scattered pale short stalked stellate setae; ventral setae of face and sides simple; setae almost absent on face. Instar 3 is similar but on the lower part of the face the setae are in groups of 2–3 from a common origin. A fourth instar caterpillar (89/3) measured about 10 mm several days after moulting. Head dark, almost black; rugose with reticulate ridges; covered with very short fine white hair-like setae in tufts of 2–4 from common origin; upper face almost bare. Body translucent dull, dark green speckled with yellow dots; narrow yellow-white dorsolateral line T2–A9; trachea visible as a faint white lateral line; legs concolorous; spiracles inconspicuous.

The fifth instar is as shown in Figure 59 . When photographed in the middle of the final instar, caterpillar 89/3 measured 22 mm. Head dark brown-black, rounded, quite deeply indented at vertex, covered with scattered short white setae in tufts of 2–4 with a common origin. Body dull translucent green, covered with scattered short, pale, stalked stellate setae ( Figure 59.2 ), which are visible as pale dots, and give an overall impression of whitish green; pale blue-green ventrally; diffuse white dorsolateral line from T2 to A9; darker dorsal line defined by subdorsal fat bodies visible through cuticle; pale male gonads indistinctly visible dorsally on A5–A6, reaching as far as the dorsolateral line; legs concolorous; spiracles pale.

Head measurements, wide x high (number of samples): instar 1 0.52 x 0.50 mm (1); instar 2 0.81 x 0.81 mm (1); instar 3 1.19 x 1.19 mm (2); instar 4 1.88 x 1.83 mm (4); instar 5 2.68 x 2.59 mm (5). The early instars last about five days each and the final instar lasts 12–16 days. For one individual (89/3) the five caterpillar instars lasted a total of about 33 days.

Pupa

The pupa ( Figure 60 ) is similar to those of S. phidyle and S. motozi . It is supported by a Y shaped girdle in a shelter of two or three leaves drawn together (in captivity). The pupa of 89/3 measured 15 mm; light green, covered with white waxy powder; spiracle T1 small, mat black; other spiracles brown, and less conspicuous.; erect pale, short setae on anterior and posterior parts of eye, but not on vertical line through middle of eye. The pupal stage lasts 14–16 days, giving a total life cycle of about eight weeks.

Natural enemies

Two caterpillars collected on J. flava at Kisii (90/88) were parasitized by Apanteles (s.l.) sp. In one example, the Apanteles larvae were visible within the final instar caterpillar, but it died without the parasitoids completing development (90/88A). A penultimate instar caterpillar, collected on the same occasion (90/88C), produced a single larva, which spun up an Apanteles (s.l.) sp. cocoon, which may represent the same or another species. The third caterpillar collected on this occasion died in the penultimate instar for no obvious reason. It is possible that these observations represent an Apanteles sp. attempting to parasitize a host outside its normal host species range, with reduced success.

Figures

FIGURE 59. Final instar caterpillar of Sarangesa haplopa. Collected as ovum observed laid on Justicia flava, Kakamega Forest, 6 Jan 1989; moulted to fifth instar 9 Feb; photographed 14 Feb, 22 mm; pupated 17–20 Feb; 89/3. 1, dorsolateral view. 2, details of head, anterior view.

FIGURE 60. Pupa of Sarangesa haplopa. Collected as ovum observed laid on Justicia flava, Kakamega Forest, 6 Jan 1989; pupated 17–20 Feb; photographed 27 Feb, 15 mm; male emerged 5 Mar; 89/3. 1, dorsolateral view. 2, lateral view.