Artitropa erinnys nyasae Riley, 1925

Cock, Matthew J. W., Congdon, T. Colin E. & Collins, Steve C., 2015, Observations on the Biology of Afrotropical Hesperiidae (Lepidoptera). Part 8. Hesperiinae incertae sedis: Dracaena Feeders, Zootaxa 3985 (3), pp. 301-348 : 334-335

Artitropa erinnys nyasae Riley, 1925

Riley (1925) describes this species from Mt. Mulanje (= Mlanje), south-east Malawi and lists material from Zomba and Blantyre, southern Malawi, which are not explicitly included in the type series. MJWC has found it at Lilongwe, central Malawi. Kielland (1990) records that TCEC reared this ssp. from a Dracaena sp. near Tukuyu, south-western Tanzania. It has also been reported from east Zimbabwe ( Pringle et al. 1994, Henning et al. 1997), where Ivan Bampton reared it from Mt. Selinda (ABRI specimens), but as pointed out in the introduction to A. erinnys , this may well be a different subspecies, and we do not have any information on the early stages.

Food plants. MJWC collected ova and small caterpillars off D. sp. probably steudneri in Lilongwe, Malawi (01/101). TCEC has reared it from D. steudneri at Tukuyu, Tanzania, and from Mt. Mulanje, Malawi, where D. steudneri is planted in the gardens of the old tea plantation houses.

Life history. The material that TCEC reared from Mt. Mulanje and that which MJWC reared from Lilongwe show significant differences in the final instar head colour. The final instar from Mt. Mulanje ( Figure 29 ) has the head orange brown, and the face yellow brown; two large black spots on the face on each epicranium, and another posterolaterally; a black line line through stemmata; a small spot at apex of frons and a black line on exterior margin of adfrontals dorsal to the frons; in some individuals the markings on the frons and adfrontals are absent (Figure 29.3).

MJWC reared a male from an ovum collected at Lilongwe. Two ova were found on sucker growth of a mature D. steudneri , one on a leaf margin, the other 15mm from the edge. The newly eclosed caterpillars ate the eggshell down to the substrate. There were five instars. The black head of instar 1 measured 1.0 x 1.0mm wide x high; body initially yellowish white, becoming pale green. In the first day it made a shelter by rolling the leaf margin over between two notches. On the second day it made a third notch beyond the existing shelter and then rolled the whole shelter further over, using silk strands attached to the outside of the shelter and the leaf lamina to do this. The newly moulted instar 2 measured 9mm; head capsule lost so not measured; head black; pronotum narrow, black; body dull translucent green; anal plate black (Figure 30.1–2). The head of instar 3 already showed the markings of the later instars: 1.7 x 2.3mm wide x high; pale straw ground colour including epicranial and adfrontal sutures, clypeal sutures slightly darker; posterior margin dark with a diffuse margin; black spot on epicranium near top of adfrontals; diffuse dark spot on epicranium at level of mid-frons; weak diffuse dark lateral spot; dark line through anterior stemmata. Instar 4 head measured 2.5 x 2.9mm wide x high; light brown ground colour; posterior margin dark; black spots positioned as instar 3; black line through anterior stemmata. The final instar head measured 3.7 x 4.5 mm wide x high; ground colour brown, with the face partially orange-brown (Figure 30.4–5), compared to orange-brown with the face yellow brown for Mt. Mulanje material ( Figure 29 ). The wax glands extended over the ventral area of A1–8.

The pupa was similar to other Artitropa spp., the proboscis extending slightly beyond the end of the cremaster; small patch of erect, backward-pointing pale brown setae on dorsum of T2 and in line down middle of eye; pale with some dark markings: an arc dorsally along posterior margin of T2, dorsal and ventral areas of head, posterior half of eye; spiracles pale brown; multiple stranded silk girdle between A2 and A3 (the girdle had dug into the dorsal part of the wing cases, causing the damage visible in the adult in Figure 30.6).

Figures

FIGURE 29. Detail of head of final instar caterpillar of Artitropa erinnys nyasae collected on Dracaena sp., Ruo Gorge, Mt. Mulanje, Malawi, 29 Feb 2008 [TCEC]. 1 – 2, anterolateral view; 3, anterior view.