Artitropa Holland 1896

Artitropa sp. SCC01 and SCC02

ABRI collectors found and reared a population of this undescribed species in the Montagne d’Ambre, northern Madagascar, and have referred to it in unpublished reports as A. alaotrana Oberthür or close. It is not A. alaotrana, and indeed appears to be closer to A. hollandi Oberthür, and will be described as new by D.C. Lees (pers. comm.). For the moment we refer to it as Artitropa sp. SCC01, based on the convention described by Janzen et al. (2009). Further similar material was collected at Anjozorobe, in central Madagascar about 100km north of Antananarivo, which may well represent an additional species or subspecies, and we refer to this here as Artitropa sp. SCC02.

Life history. At Montagne d’Ambre, the food plant of Artitropa sp. SCC01 was an unidentified Dracaena sp. resembling the mainland D. mannii, presumably Clade A of Buerki et al. (2009). Caterpillars were found on small plants on the edges of open spaces. The newly-laid ovum (Figure 8.1–2) is salmon in colour and typical of Artitropa spp. The final instar caterpillar has a distinctive brown head with a black central marking across the centre of the face extending into the dorsal part of the adfrontals, and surrounded by a halo of very pale brown (Figure 8.3–5). The pupa is typical in shape for Artitropa, but the colouring and markings are not yet visible in the newly moulted pupa shown in Figure 8.6.

At Anjozorobe in November 2006, SCC collected caterpillars of Artitropa sp. SCC02 on a narrow-leaved Dracaena sp., similar to or the same as that used by Artitropa sp. SCC01 in the north of Madagascar. The caterpillars were similar to those of the population from Montagne d’Ambre, but the head ground colour is green rather than brown, the central area appears narrower, and the halo around it is whiter and more sharply defined on the external margin (Figure 8.7). The pupa was not documented.

At this stage, the difference in the caterpillars and adults of the two early stages suggest two taxa are involved, but this requires further investigation. The caterpillar head markings of these two taxa are completely distinct from those of the other described species of Artitropa, but not dissimilar to those of G. shelleyi (Figure 4).