Coeliades sejuncta (Mabille & Vuillot)

Cock, Matthew J. W., 2010, Observations on the biology of Afro-tropical Hesperiidae (Lepidoptera) principally from Kenya. Part 1. Introduction and Coeliadinae, Zootaxa 2547, pp. 1-63 : 44-48

Coeliades sejuncta (Mabille & Vuillot) ( Figures 36–41 )

Coeliades sejuncta was described from Ussagara, Tanzania, and is restricted to Malawi, Tanzania and Kenya. In Kenya this species is restricted to the coastal strip, where it is not especially common in bush and forest. I have only come across it in the Jadini Forest behind Diani Beach, but Sevastopulo (1974) records it as uncommon in Makadara Forest.

Adult behaviour

I have only occasionally seen the adults ( Figure 36 ), for example in the late afternoon / early evening (21.viii.1995, 18.00h) looking for oviposition sites on Triaspis mozambica at Diani Beach. Larsen (1991) records the adults coming to flowers, but I have not seen this or adults drinking. At Bahari Beach, north of Dar es Salaam, I did see an adult attracted to hotel lights, 13 Jun 1989. This is the only observation I know of a Coeliades sp. coming to light. It may represent a late flying individual, or a specimen disturbed from its roosting site and then attracted to the light.

Food plants

I have found caterpillars on Triaspis mozambica and Acridocarpus zanzibaricus ( Figure 43 ). The latter may not be the normal food plant, since although I once reared a small batch of caterpillars from a shady part of the Jadini Forest (adjacent to the Robinson Baobab Forest) where they were feeding on one plant of A. zanzibaricus , I did not find C. sejuncta caterpillars on this food plant again, although it is a species that I checked several times subsequently. van Someren (1974) also recorded A. zanzibaricus as a food plant. Sevastopulo (unpublished) reared this species from an unknown creeper at Mombasa, which could have been a species of Triaspis or Acridocarpus , but subsequently he records the food plant as Acridocarpus sp. ( Sevastopulo 1974, 1975).

Ovum

The ova measure 0.9 x 0.6mm wide x high and have 15–16 ribs; microsculpture similar to Pyrrhiades a. anchises but finer. Ova may be laid on the leaf under surface, leaf upper surface or on the plant stems. The ova are cream-coloured when newly laid, becoming white, and then turning dark before eclosion.

Leaf shelters

On Triaspis mozambica the stage I shelter is a small (3–4 mm wide, 4–5 mm long) lid cut from the edge of the leaf with two major cuts and folded upwards, i.e. a type 5 two–cut shelter (Type 9 of Greeney & Jones (2003)). To construct the stage 2 shelter ( Figure 37 ), the caterpillar uses a leaf of about 35 mm, making a major cut from each edge of the lamina to the mid-rib, between 5 and 15 mm from the base; the mid rib is bared for 2–6 mm at this point; the distal part of the leaf is rolled upwards to form a tube, initially about 25 mm long, but it immediately starts to shrivel, and by the time the shelter is abandoned the leaf is clearly dead; the outer margins of the leaf incorporated into the shelter are lined with two irregular rows of holes of about 2mm diameter; the distal and basal margin of the shelter is left irregular, and there may be some feeding on the basal remnant of leaf. The distal end of the shelter is formed by making two more major cuts—i.e. this is a type 6 four–cut shelter.

The fourth and fifth instar caterpillars hardly make a shelter on A. zanzibaricus , but roll the leaf upwards slightly and pull it together with a couple of strands of silk—a type 1 no–cut shelter. They do not feed on the leaf in which they shelter. Two leaves of A. zanzibaricus with stage two shelters, similar to those described above on T. mozambica , were found on the ground below the food plant. These may have dehisced naturally, or they could have been cut off by the caterpillars, or could the plant have shed them in response to caterpillar feeding damage?

Caterpillar

Like C. f. forestan (above), this species has only five caterpillar instars. The last instar lasted 7 days at the coast, but 16 at Nairobi.

Instar 5 ( Figure 38 ). The following description is based on caterpillars collected on Acridocarpus zanzibaricus beside a path in the disturbed Jadini Forest behind Diani Beach on 28 and 31 Mar 1989 (89/20). When newly moulted, the caterpillar (89/20A) measured 36mm, and grew to 40mm on 1 Apr, before pupating on 5 Apr. The following description was made of the newly moulted caterpillar after one day. Head approx 4.7 x 4.4mm wide x high (average 4.2 x 4.2, n=5); orange brown with two rows of black spots: upper row of four, inner spots large, outer spots extended laterally; lower row of five, central spot small, outer spots slightly more ventral and covering stemmata. T1 black, with complete white band in the middle. T2 similar, but white band stops at the top of the legs. T3 similar, but also has a partial band in the anterior half comprising a long dorsolateral streak, a short white lateral streak, and then continued ventrally on the anterior margin. A1–7 black; near anterior margin a partial white band as T3 , fainter on A1, but strong, with a more rounded lateral white mark on A2–A7; in posterior half a double orange band divided by a narrow black line, stopping short of spiracle (anterior line) or level with spiracle (posterior line); white band near posterior margin to level with posterior orange band; a white spot ventral to the end of the posterior orange band and the white band; ventrally deep dark red. A7 similar but orange bands almost fused. A8 similar but anterior white band almost complete and orange bands fused, with no dividing black line. A9 black with an orange band which laterally angles forwards to reach the white band on the posterior margin of A8; a lateral white spot. True legs black; prolegs red, but not as dark as adjacent body. Spiracles small, inconspicuous, white .

I noted that when feeding on A. zanzibaricus for at least part of the final instar the caterpillar positions its terminal segments out of the leaf shelter and merely lets its frass drop, rather than flick it away as other Hesperiidae do. On the smooth leaves of A. zanzibaricus the large frass produced by this instar immediately rolled off the leaf and dropped to the ground.

Instars 3 and 4 are similar to instar 5, but the white markings in the anterior half of segments T2–A8 may be present ( Figure 39 ) or absent ( Figure 40 , left) in instar 4, but absent in instar 3 ( Figure 40 , right). The head capsules measured: instar 3 1.4 x 1.4mm (n=6), instar 4 2.5 x 2.6mm wide x high (n=11).

Instar 1. The head measures 0.5 x 0.4mm wide x high (n=2); pale brown, unmarked except for a black patch over stemmata.

Pupa

The pupa is similar to others of the genus, covered with white waxy powder, with small black spots. The pupa of male individual 89/20A ( Figure 41 ) measured 24 mm; pupation lasted 16 days, and the following notes were made when the pupa was one day old. Under the white waxy bloom, the head and thorax tinged green and the abdomen brown. 1mm frontal spike dark under white waxy bloom. Black spots as follows: a dot in the centre of the eye; ventrally between eyes a row of four spots and posterior to this a central spot; end forewing cell a triangle about 1mm long; a 1.5mm streak in centre of forewing space 1; three indistinct spots on leg of T1, and two on leg of T2; A9 a narrow transverse dorsolateral streak; A10 dorsolateral and ventral dots. T1 spiracle black, projecting and conspicuous; abdominal spiracles small, black. Four male pupae took 14–16 days to emerge under Nairobi conditions.

Natural enemies

Three of 12 ova collected at Diani Beach, 21 Aug 1995 (95/105) were parasitized by a solitary black egg parasitoid.

Figures

FIGURE 36. Newly emerged male Coeliades sejuncta, reared from caterpillar collected on Acridocarpus zanzibaricus, Diani Beach, 28 Mar 1989 (89/20C).

FIGURE 37. Stage 2 leaf shelters of Coeliades sejuncta, which contained instar 3 caterpillars, collected on Triaspis mozambica, Diani Beach, 21 Aug 1995 (95/105).

FIGURE 38. Instar 5 caterpillar of Coeliades sejuncta collected on Triaspis mozambica, Diani Beach, 21 Aug 1995, moulted to L5 27 Aug, (95/105A); left caterpillar, photographed 1 Sep, 38mm; right, detail of head, photographed 10 Sep.

FIGURE 39. Instar 4 caterpillar of Coeliades sejuncta about to moult to instar 5, collected on Acridocarpus zanzibaricus, Diani Beach, 28 Mar 1989 (89/20A).

FIGURE 40. Left, instar 4 caterpillar of Coeliades sejuncta collected on Acridocarpus zanzibaricus, Diani Beach, 28 Mar 1989, moulted 28 Mar, photographed 29 Mar, 36mm (89/20); right, instar 3 caterpillar of C. sejuncta collected on Triaspis mozambica, Diani Beach, 21 Aug 1995, 9mm (95/105).

FIGURE 41. Pupa of Coeliades sejuncta collected as caterpillar on Acridocarpus zanzibaricus, Diani Beach, 28 Mar 1989, pupated 4 Apr, photographed 5 Apr, 24mm (89/20A); left, ventrolateral view; right, lateral view.

Figure 43. Acridocarpus zanzibaricus, Diani Beach, 15 Dec 1989; food plant for Coeliades kenya, C. sejuncta and Pyrrhiades a. anchises.