Artitropa comus Stoll, 1782

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 : 320

Artitropa comus Stoll , [1782]

Although the original type locality was given by Stoll (1780 –1782) as Surinam, this was an error, and the type locality is accepted as West Africa ( Ackery et al. 1995). This is the only species of the genus in West Africa ( Larsen 2005), and its distribution extends east to Cameroon, Republic of Congo, Gabon and DR Congo ( Ackery et al. 1995, Larsen 2005). Heath et al.’s (2002) record from Zambia (‘Hillwood (Ikelenge) (ABRI)’) was based on a misidentification for A. reducta . In Cameroon and Congo its range overlaps with A. reducta , which for many years was considered a subspecies. In his simplified provisional check-list of the butterflies of the Afrotropical region, Carcasson (1981) first treated reducta Riley as a valid species separate from A. comus , but gave no explanation. This situation remained unchanged when Carcasson’s catalogue was published by Ackery et al. (1995), and was endorsed by Larsen (2005). Given that the two species overlap in Cameroon and the Congo, their separation seems a priori to be justified.

Most of Riley’s (1925) information on the early stages of ‘ A. comus ’ is, given the locality ( Uganda), actually referable to A. reducta , which Riley treated as a subspecies of A. comus . However, Riley goes on to point out that the early stages of A. comus are similar based on preserved material from Lagos in the Oxford University Museum. Riley does not explicitly state the food plant of the Lagos material, which he states comprises a male and five females reared by Dr. W.A. Lamborn. MJWC examined this material in HEC; it actually comprises four females from Dr Lamborn, two of which were reared from pupae, all from near Oni, 70 miles east of Lagos (cf. Gamia buchholzi above), and two males and a female caught in Lagos by J.A. de Gaye in 1912. The two reared females were collected as pupae ‘in forest, Sep 1911, and there is no indication as to the food plant. There are associated emerged pupae for both, of which one has the associated cast final caterpillar skin and head capsule. The head markings and spot on T1 are comparable to those shown below for A. reducta ( Figures 18–21 ).

The food plant records of Le Pelley (1959), Sevastopulo (1974, 1975), Van Someren (1974), Carcasson (1981), Ackery et al. (1995), Heath et al. (2002), etc. are considered to refer to A. reducta .

In 1994, MJWC found a dead final instar caterpillar and a pupa killed by a parasitoid with the cast final instar skin on a Dracaena sp. at Toumodi, near Yamoussoukro, Côte d’Ivoire. The caterpillar head was similar to that of A. reducta (below): 3.65 x 4.2mm wide x high; pale brown with yellow flush on face; rugose, no obvious setae; large oval dark spot on each epicranium, the lower inner margin adjacent to upper adfrontals; posterior margin, sutures, adfrontals and frons all ground colour; pronotum pale with a dark spot laterally. The pupa was similar to those of other Artitropa spp.: unmarked pale brown; erect pale brown setae in small patch on T3 dorsum, directed backwards, and in line down centre of eye. The pupa had a single 1.6mm diameter parasitoid emergence hole cut in the front of the head.

The first unequivocal published food plant record for A. comus is that of Vuattoux (1999) who reared a dozen on D. mannii (as D. perrottetii ). We can find no significant differences between the early stages of A. comus and those of A. reducta ( Figures 18–21 ). SCC has found early stages of A. comus in several countries in west and central Africa on a variety of Dracaena spp., including exotics, including D. fragrans in Liberia, at Obudu, eastern Nigeria (April 2007) and in Cameroon, D. mannii in Ghana and Côte d’Ivoire, and D. arborea on Bioko (Dec 2011). They can be horticultural pests of ornamental Dracaena spp., and adults have been observed to come to light.

Figures

FIGURE 18. Final instar caterpillars of Artitropa reducta, collected as small caterpillar on D. steudneri, Kigale, Rwanda, 7 Feb 1990; moulted to final instar 21 Feb; photographed 22 Feb, 37 mm; pupated 4 Mar; 90 / 201 A: 1, dorsolateral view; 2, detail of head, anterolateral view.

FIGURE 19. Final instar caterpillar of Artitropa reducta collected on either Dracaena fragrans or D. steudneri, western Kenya [SCC]. 1, dorsal view, 1 Jan 2004; 2, detail of head, anterior view, 27 Sep 2004.

FIGURE 20. Ovum and caterpillar of Artitropa reducta, collected on Dracaena mannii, Lisombo Stream, north-west Zambia [TCEC]. 1, ovum, dorsal view, 18 Nov 2005; 2, lateral view, 21 May 2000; 3, head and anterior segments, final instar caterpillar, dorsal view; 3 Nov 2004. 4, head, final instar caterpillar, anterior view, 11 May 2000; 5, final instar caterpillar, dorsolateral view, 11 May 2000.

FIGURE 21. Ovum and caterpillars of Artitropa reducta, collected on Dracaena mannii, Rondo Plateau, south-eastern Tanzania [TCEC]. 1, ovum, dorsal view 19 Feb 2001; 2, ovum, lateral view, 19 Feb 2001. 3, final instar, detail of head, anterior view, 9 Feb 2005; 4, detail of head, anterior view, 28 Mar 1998; 5, final instar dorsal view, 9 Feb 2005.