Moltena fiara Butler, 1870

Cock, Matthew J. W., Congdon, T. Colin E. & Collins, Steve C., 2016, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 9. Hesperiinae incertae sedis: Zingiberales feeders, genera of unknown biology and an overview of the Hesperiinae incertae sedis, Zootaxa 4066 (3), pp. 201-247 : 234-236

Moltena fiara Butler, 1870

Butler (1870) described this species from ‘Kaffraria’ (southern Africa) and it is known from coastal areas of South Africa from Eastern Cape to southern Mozambique ( Pringle et al. 1994, Ackery et al. 1995, Henning et al. 1997). The adults are known to fly at dusk ( Trimen 1889) and are sometimes attracted to light ( Migdoll 1988, Woodhall 2005).

Food plants. The food plant is a species of Strelitzia (Strelitziaceae) . Strelitziaceae includes three genera, all occurring in tropical to subtropical regions: Strelitzia with 5 species in southern Africa, Ravenala with a single species indigenous to Madagascar, and Phenakospermum with a single species in northern South America. The best known species is the bird-of-paradise flower Strelitzia reginae , grown for its flowers worldwide in tropical and subtropical gardens, but this does not seem to be a normal food plant for M. fiara , although SCC was able to rear caterpillars through on this plant in captivity. The other species of Strelitzia have less colourful flowers, but may be grown for their striking foliage (Wikipedia 2014).

The first food plant record is that of Leigh (1910) from ‘wild banana’ which refers to S. nicolai , also known as the giant white bird-of-paradise, and this is also the food plant listed in recent works ( Dickson & Kroon 1978, Migdoll 1988, Pringle et al. 1994, Henning et al. 1997, Woodhall 2005). However, in his list of food plants of South African Lepidoptera, Platt (1921) lists only S. augusta , which is a synonym of S. alba , the white bird-ofparadise. Murray (1932) presents the information of Leigh (1910), but refers to the food plant as S. augusta (i.e. S. alba ), and uses this name again later ( Murray 1959). Strelitzia alba and S. nicolai are both arborescent species with white flowers, and it would seem that in this context, entomologists misapplied the former name in the middle of last century.

Life history. Leigh (1910) provided a fairly detailed description of the life history that was not improved until G.C. Clark’s detailed life history plate was published ( Dickson & Kroon 1978, Plate 28). Subsequently Migdoll (1988) provided photographs of the caterpillar and food plant, and Henning et al. (1997) of the caterpillar and pupa. We cannot add anything significant to these, but include SCC’s photographs of the penultimate and final instar caterpillar and pupa for comparison with other Hesperiinae incertae sedis. The ovum is reported to be 2.0 x 1.8mm diameter x height, with ‘30-40 longitudinal ribs, a third of which stop part of the way up the side, the remainder joining in pairs to form a single very short rib just short of the micropyle’ (G.C. Clark in Dickson & Kroon 1978). The caterpillar ( Figure 38 ) is distinctive due to the orange markings around spiracles A1–A8, variable dark late instar head markings, and the variable dark anal plate, especially in the third to penultimate instars. The pupating caterpillar and pupa are covered with white waxy powder.

Natural enemies. G.C. Clark (in Dickson & Kroon 1978) records that a tachinid, Thecocarcelia incedens (Rondani) has been reared from the pupa –– the same species was also reared from Artitropa erinnyis erinnyis (Trimen) , as discussed in (Cock et al. 2015). Based on an ovum preserved in ABRI (on Strelitzia, Margate, Natal , South Africa, 28 Nov 1998), there is also at least one egg parasitoid that attacks M. fiara .

Discussion. As noted in the introduction to Moltena above, De Jong (1986) found that based on an analysis of adult characters Chondrolepis seems to form a monophyletic group with Ploetzia and Moltena , with Zophopetes as their nearest relative. We have illustrated the early stages of the sole species of Ploetzia and three species of Zophopetes in Cock et al. (2014), and of four species of Chondrolepis in Cock & Congdon (2014). The food plants are varied: P. amygdalis (Mabille) and Zophopetes spp. are palm-feeders, Chondrolepis spp. are grass feeders and M. fiara feeds on Strelitzia . We have not examined ova of Chondrolepis spp., but the ova of Ploetzia , Zophopetes and Moltena are all dome-shaped and ribbed, although the detail of the number and arrangement of the ribs is variable. The caterpillars of all four genera are broadly similar, although only M. fiara has the dark anal plate and orange spots around the A1–A8 spiracles and Chondrolepis spp. have more conspicuous setae especially on the head. The pupae of Ploetzia , Zophopetes and Moltena are all similar, having no real distinguishing features, being similar in shape, attached at the cremaster and with white waxy powder. In contrast, the pupae of Chondrolepis spp., which are formed in shelters of rolled grass leaves, are more cylindrical, have a short down-turned frontal projection, have more developed setae dorsally and on the abdomen, lie free in the pupal chamber, are not attached at the cremaster, and have little or no white waxy powder. On balance, the early stages would seem to indicate that Ploetzia , Zophopetes and Moltena show clear affinities, but Chondrolepis are somewhat separated, although to some degree, this difference may be a reflection of adaptations by Chondrolepis spp. to feeding on a relatively soft grass, and making a tight pupal chamber.

Figures

FIGURE 38. Caterpillars of Moltena fiara collected on Strelitzia nicolai, south coast of Durban, South Africa, photographed 30 Mar 2004 [SCC]. 1, penultimate instar, dorsal view; 2, final instar, detail of head, anterolateral view; 3, final instar, dorsal view; 4, final instar, lateral view.