Artitropa erinnys ehlersi Karsch, 1896

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 : 332-333

Artitropa erinnys ehlersi Karsch, 1896

Karsch (1896) described Artitropa ehlersi based on specimens from Kilimanjaro (= Kilimandjaro) collected by the explorer [Otto E.] Ehlers (now in the Berlin Museum and the only type referred to by Evans (1937)) and the area around Mlalo, north Usambara Mountains, collected by the botanist [Carl H.E.W.] Holst. It is known to occur from coastal Kenya ( Larsen 1991) and coastal Tanzania inland to Mt. Meru in the north ( Kielland 1990), and south to the Rondo Plateau in south-eastern Tanzania (TCEC) and Mt. Makulu, Mozambique (ABRI coll.). Sevastopulo (1974, unpublished) records it from the Shimba Hills, V.G.L. Van Someren from the Rabai Hills (BMNH accessions; 7 specimens, 1933–34) and SCC has reared it from several locations around Mombasa and Watamu in 2008. Larsen (1991) refers to it occurring in the Teita Hills of southern Kenya, but we treat this population as ssp. radiata (above). Subspecies ehlersi is not rare around Arusha, where SCC found it flying in the middle of town.

Food plants. Van Someren (1974) lists several Dracaena spp. as food plants for A. erinnys ‘and subspecies’. Of these, D. mannii is only found in the coastal area of Kenya, and so this record must apply to A. e. ehlersi . Sevastopulo (1974) reports A. erinnys radiata caterpillars as not uncommon in the Makardara Forest on Dracaena sp. and documented the final instar and pupa (Sevastopulo unpublished); we treat this population as A. erinnys ehlersi . SCC has reared A. erinnys ehlersi from D. fragrans around Mombasa and Watamu at the Kenya Coast. In TCEC’s experience the normal food plant seems to be D. mannii , but it has also been collected on D. steudneri (Dar es Salaam, Nguru Mountains and Usa River, Arusha).

Life history, Kenya Coast and Shimba Hills. Sevastopulo (unpublished) documented the early stages based on a full grown caterpillar found on a Dracaena sp. at Kwale, Kenya, in June 1963, which he treated as ssp. radiata. Caterpillar ‘head dull yellow, the frons [dorsal part of adfrontals] edged with black and with two large black spots, one below the other on each lobe [epicranium]; a smaller black lateral spot, posteriorly. First somite [T1] with a distinct neck and a black lateral spot. Colour greyish green, a darker dorsal line due to the intestinal canal. Anal flap flat, edged with whitish forming a heart shaped mark, with a blackish spot in each of the curves above. Legs, prolegs and venter green. Spiracles white. The anal flap showing through the end of the cell [leaf shelter] is slightly reminiscent of a lizard’s head, the pale line making the outline of the jaws and the black spots the eyes. In the early instars the whole heart shaped mark is black.’ Sevastopulo’s photos include an anterior shot of the head; the dark dorsal part of the adfrontals and frons making an inverted W-shape in the centre of the face.

Sevastopulo also records that the pupa as formed ‘in the old larval cell [leaf shelter] now lined with silk and coated with a waxy powder, and closed anteriorly by a silken curtain. Head, thorax and wing cases green, the abdomen yellow, the whole so heavily coated by a white waxy powder that the actual colour is more [or] less concealed. Supported by a girdle and the cremaster being fixed in the silk lining of the cell. Shape very moth-like, the head rounded without any central projection. The proboscis sheath extending some 5mm beyond the apex of the abdomen.’ The pupa eclosed in 12 days.

A final instar caterpillar that SCC reared from the Kenya Coast (Figure 28.1) matches those of A. erinnys radiata (Teita Hills, Mt. Sagalla, Kasigau), except that the vertical streak on the frons is reduced to an ill-defined spot. The caterpillars of A. erinnys radiata and coastal Kenyan populations of A. erinnys ehlersi have a lateral spot on the head, which is not found in A. erinnys ehlersi from Tanzania, where the other head markings of A. erinnys ehlersi are larger and darker. This suggests that the Kenya Coast population may be closer to A. erinnys radiata than to A. erinnys ehlersi , but we have not documented enough material to assess individual variation in these populations.

Life history, Tanzania. The final instar caterpillar (Figure 28.1–2) resembles that of A. e. erinnys (Figure 33.1–3), although the spots on the head may be larger. A caterpillar TCEC collected on D. steudneri , Dar es Salaam, 22 Apr 2013, is similar but the lower epicranium spot on the face is dark brown rather than black. Caterpillars from the Nguru Mountains, Tanzania, lack the markings on the adfrontals and have smaller black spots on the face (Figure 28.3–4). This difference in the caterpillars is comparable to the differences between species in this genus, suggesting they deserve evaluation as a distinct taxon.