Triskelionia compacta ( Evans 1951 )

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 : 62-63

Triskelionia compacta ( Evans 1951) ( Figures 65–66 )

This species was known only from the type series from ‘ Mikindani’ , in the extreme south east of Tanzania ( Evans 1951). Mikindani was the regional headquarters under German administration, so the locality may not be precise. TCEC has now found compacta on the Rondo Plateau, in the same general area, and reared it .

Food plants

Dalbergia armata (Fabaceae) is the food plant on the Rondo Plateau, Tanzania, making this the only African member of the Celaenorrhinini that is known to feed on a plant of a family other than Acanthaceae , apart from Katreus dimidia , which as noted above has been recorded from an Apocynaceae . Dalbergia armata is known from the Rondo Plateau, where TCEC found compacta ova and caterpillars, and from Mozambique to Kwa-Zulu Natal. TCEC also found it quite commonly in the Litipo forest near Lake Lutambo, below the Rondo, so it is possible that T. compacta may be found there also. The limited distribution of the food plant in Tanzania could account for the rarity of the butterfly.

Early stages

As shown in Figure 65.1 , the ovum is white with 14 strong wall-like ribs, about half of which reach the micropyle. The food plant has fine compound leaves with tiny leaflets, rather like an Indigofera sp. First instar caterpillars simply bind two leaflets together and hide between them. Subsequent instars bind leaflets from opposite sides of the midrib, and as there are gaps between the leaflets, the caterpillar is just visible in the shelter.

The final instar caterpillar ( Figures 65.2–3 ) has the head uniform light brown, with the posterior margin dark. The body is pale yellow-green and densely covered with white dots. It does not closely resemble any of the species of Sarangesa that we have reared.

The pupa ( Figure 66 ) is smooth, white; no protruding proboscis sheath; a short very broad pale brown frontal Discussion

The ovum of T. compacta with wall like ribs is similar to those of Sarangesa and Eretis , but not to those of Celaenorrhinus . The caterpillar, with a brown rugose head and a uniform pale speckled body, does not closely resemble those of any other Celaenorrhinini . The smooth, pale pupa, with a weak broad pale brown frontal projection also does not match those of other Celaenorrhinini genera. Furthermore, as already noted, T. compacta also has the distinction of being the only African species of Celaenorrhinini so far known, apart from K. dimidia , that does not feed on Acanthaceae . These differences, together with the adult morphological characters, justify the establishment of Triskelionia ( Larsen & Congdon 2011) .

Figures

FIGURE 65. Ovum and final instar caterpillar of Triskelionia compacta, collected on Dalbergia armata, Rondo Plateau, 850 m, Tanzania (TCEC). 1, ovum, 24 Feb 2001. 2, final instar caterpillar, dorsolateral view, 18 Mar 2002. 3, as 2, lateral view.

FIGURE 66. Pupa of Triskelionia compacta, collected on Dalbergia armata, Rondo Plateau, 850 m, Tanzania (TCEC).