Artitropa erinnys erinnys Trimen, 1862

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 : 336-337

Artitropa erinnys erinnys Trimen, 1862

This subspecies was originally described as Pamphila erinnys from a single male (in BMNH) from Durban (= Port Natal) ( Trimen 1862, Evans 1937). The subspecies is found near the east coast of southern Africa, from East London, Eastern Cape Province to Northern Province, South Africa, Swaziland and far southern Mozambique. There is a long series in the BMNH, of which one male from Zululand (within Kwa-Zulu Natal Province, South Africa, and representative of the type locality) has been dissected by W.H. Evans and is the basis of his diagram of the genitalia of this species ( Evans 1937).

Adult behaviour. Trimen (1889) reported that the adult ‘flies about sunset, as a rule, but on damp and cloudy days will visit flowers much earlier in the afternoon’ including Petunia , Campanula , Crotalaria and honeysuckle. Subsequent authors have referred to it as crepuscular ( Dickson & Kroon 1978, Migdoll 1988, Pringle et al. 1994, Henning et al. 1997), but none include observations of early morning flight.

Food plants. Leigh (1911), Platt (1921), Swanepoel (1953), Murray (1959) and Swain & Prinsloo (1986) give the food plant as Dracaena aletriformis (as D. hookeriana ). Van Someren (1974) lists the food plants of A. erinnys ‘and subspecies’ as D. reflexa , D. fragrans , D. afromontana and D. mannii (as D. nitens ) for this skipper, but we consider these to be records from East Africa, and hence discount them when Kielland (1990) specifically lists them for ssp. erinnys .

Dickson & Kroon (1978), Migdoll (1988) and Pringle et al. (1994) give D. aletriformis (as D. hookeriana ) and D. steudneri as food plants. However, when Henning et al. (1997) and Woodhall (2005) add D. afromontana , D. angustifolia , and D. fragrans , it seems likely that these are derived from Van Someren’s East African records again, and not applicable to ssp. erinnys .

Life history. The life history of A. e. erinnys is one of the best documented for African Hesperiidae . Leigh (1911) described the early stages and leaf shelters. Murray (1932) described the early stages and illustrated them with line drawings. Clark (in Dickson & Kroon (1978), Plate 30) painted a detailed life history; there are six caterpillar instars; only instar 1 has a dark head and in successive instars the head is increasingly spotted. Migdoll (1988) includes photographs of a caterpillar (with well-developed wax glands), pupa and food plant (which appears to be D. aletriformis ). Henning et al. (1997) also include photographs of the final instar caterpillar and pupa.

Here we include exceptional photographs of the ovum and first instar caterpillar, taken by Steve Woodhall. The ovum resembles those of other members of the genus, but the microsculpture is much clearer in this photo ( Figure 31 ). It can be seen how the numerous, fine vertical ribs are composed of a series of very small bumps, like a string of beads, extending from the base to about two-thirds of the height. At this point the ribs start to break up into fragments, and then polygons before the flat micropyle. Between the vertical ribs are even finer, closely spaced horizontal bars, again of rows of very fine bumps. We consider this structure typical for the genus.

Figure 32 shows the first instar caterpillar. The head and pronotum are conspicuous very dark brown, and the body white. Setae are short, fine and hardly visible apart from those on the anal plate, which are conspicuous, robust, long and erect. This image is probably representative for the entire genus. We have observed similar setae on the first instar of other species; this may be typical of Hesperiinae , but we have not investigated this systematically.

Although good published figures of the nominate subspecies are available, for ease of comparison with other subspecies, we include additional photographs here ( Figure 33 ) of the final instar caterpillar, pupa and adult, which SCC documented from a collection made from D. aletriformis at Scotburg, Kwa-Zulu Natal, South Africa. It can be seen that the final instar caterpillar head is orange brown, the face yellow-brown, and black markings in the dorsal part of the adfrontals (separated by the orange-brown suture), two spots on the face one just above the level of the adfrontal marking and the other just below, and a lateroposterior spot.

Natural enemies. Leigh (1911) states that all early stages are attacked by parasitic wasps and flies, and insect predators, ‘ants, mantis, cockroaches, etc.’ Thecocarcelia incedens (Rondani) , a larval-pupal tachinid parasitoid has been reported from near east London, South Africa (Clark in Dickson & Kroon 1978).

Figures

FIGURE 31. Ovum of Artitropa erinnys erinnys, laid on Dracaena aletriformis, Gillitts, Durban, South Africa, photographed 18 Oct 2012, two days before hatching [© S. Woodhall].

FIGURE 32. First instar caterpillar of Artitropa erinnys erinnys, newly hatched from ovum laid on Dracaena aletriformis, Gillitts, Durban, South Africa, photographed 20 Oct 2012 [© S. Woodhall].

FIGURE 33. Caterpillar, pupa and adult of Artitropa erinnys erinnys, on Dracaena aletriformis, Scotburg, Kwa-Zulu Natal, South Africa [SCC]. 1 – 3, final instar caterpillar: 1, head, anterodorsal view, 26 Sep 2004; 2, dorsolateral view; 3, dorsolateral view. 4 – 5, pupa: 4, dorsolateral view, 23 Sep 2004; 5, lateral view, 23 Sep 2004. 7 – 8, adult female, 26 Sep 2004: 7, upper surface; 8, under surface.