Platylesches robustus robustus Neave, 1910

Cock, Matthew J. W. & Congdon, Colin E., 2013, Observations on the Biology of Afrotropical Hesperiidae (Lepidoptera). Part 5. Hesperiinae incertae sedis: Dicotyledon Feeders, Zootaxa 3724 (1), pp. 1-85 : 72-73

Platylesches robustus robustus Neave, 1910

This species was described from Chambeshi (=Chambezi) valley, north-east Zambia, and the high plateau south of Lake Tanganyika ( Neave 1910) and is known from South Africa to Tanzania and Democratic Republic of Congo ( Evans 1937, Kielland 1990), with separate subspecies in Cameroon (villa Evans, 1937) and the Republic of Guinea (fofi Larsen & Mei, 1998), which may well prove to be valid species ( Larsen & Mei 1998). TCEC has found this species at Mufindi and Kihansi in the Udzungwas, and the Usondo Plateau between Mpanda and Uvinza, Tanzania, and it is very common in the Mutinondo Wilderness, Zambia.

Coetzer (2006) presents notes on the early stages of Pl. robustus , but this was based on a misidentification of Pl. moritili (A. Coetzer pers. comm. 2010).

Food plants

Woodhall (2005) suggested the food plant is probably Pa. curatellifolia , and this is the food plant upon which TCEC found this species in Zambia and elsewhere.

Life history

Congdon et al. (2008) describe the life history. In the early instars, Pl. robustus makes shelters similar to those of Pl. shona (below). However, in the final instar, Pl. robustus makes a chamber leaf shelter ( Figure 80 ) by securing the cut section of leaf to the leaf below, and then bringing a part of the cut leaf round to block off the front of the chamber. It then makes a circular silk-lined entrance hole, and creates an external tunnel of silk which curves round, blocking the line of sight to the inside of the chamber ( Figure 80 ). They make both left and right handed tunnels, contrary to the earlier suggestion that only right handed tunnels are made ( Congdon et al. 2008). The chamber is lined with a generous layer of tough brownish silk, making it waterproof, if not bird-proof. Chambers are found among mature foliage well above the ground. The fully fed larva enters diapause for several months in the chamber before pupating, and final instar larvae from Mutinondo in Zambia, collected in November, did not pupate until May and June the following year, indicating there is probably just one generation a year. Congdon et al. (2008) suggested that the caterpillar ( Figure 81 ) is better able to defend itself against parasites and predators than a pupa would be. The pupa of this species ( Figure 82 ) is dark brown with paler bands on the abdominal segments.

Figures

FIGURE 80. Chamber leaf shelters of Platylesches robustus on Parinari curatellifolia, Mutinondo Wilderness, Zambia, TCEC. 1, general view showing two leaves pulled together, with silken entrance to the right, 4 Dec 2007; 2, closer view from above, 9 Jan 2008; 3, as #2 from below; 4, opened shelter showing caterpillar in shelter, anterior view, 9 Jan 2008.

FIGURE 81. Final instar caterpillar of Platylesches robustus collected on Parinari curatellifolia, Mutinondo Wilderness, Zambia, TCEC. 1, lateral view, 4 Dec 2007; 2, detail of head, anterior view, as #1; 3, dorsal view, as #1; 4, ready to pupate, 4 May 2008.

FIGURE 82. Pupa of Platylesches robustus collected on Parinari curatellifolia, Mutinondo Wilderness, Zambia, 3 Feb 2008, TCEC. 1, dorsal view; 2, lateral view.