Celaenorrhinus, Hubner, 1819

COCK, MATTHEW J. W. & CONGDON, T. COLIN E., 2011, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera) principally from Kenya. Part 3. Pyrginae: Celaenorrhinini, Zootaxa 3033 (1), pp. 1-67 : 8-10

Celaenorrhinus undescribed nr. dargei Berger 1976 ( Figures 1.2 , 3–5 )

T.B. Larsen (pers. comm. 2010) pointed out to me that the species known as C. proxima proxima in Kakamega Forest actually comprises two species, separated most easily by whether the two white spots in space 1B of the fore wing are separate ( C. proxima proxima ) or touching (C. undescribed nr. dargei ; Figure 3 ). On examining my material, I note that both species are present and that the valves of the male genitalia are also very distinct.

One or both of this species pair is normally to be found at Kakamega Forest, i.e. I would expect to see one or both on nearly every visit. One or both are common in the forest near the Rest House, and in the stretch by Ikuywa Stream, but less common in the North around the Park HQ. T.B. Larsen (pers. comm. 2010) considered the undescribed species to be more common, and while that is the only one of the two that I have photographed in the wild ( Figure 3 ), I have slightly more specimens of C. proxima proxima in my collection.

Adult behaviour

In the 1980s–90s, I was not aware that C. proxima proxima in Kakamega Forest was partly this undescribed species, so the following is based on observations of both species combined. The adults fly throughout the day, coming to feed at most of the ground layer nectar flowers in the forest, notably Justicia flava . Feeding is always with the wings held flat ( Figure 3.1 ). Although most active in the sun, they continue feeding in light rain when they are easier to observe and photograph. Males can be found perched on vegetation 1–2 m above the ground along the edge of the forest, along tracks and in clearings. They usually rest under leaves with their wings held flat, but sometimes, especially early in the morning, rest on the leaf upper surface in a patch of sunlight.

Food plants

I reared this species from two collections from Kakamega Forest in 1991 (91/35 on 16 Jun, 91/39 on 17 Jun), but thinking that the caterpillars were C. proxima proxima which I had reared several times before, I paid scant attention to the details, although fortunately I photographed one final instar caterpillar ( Figure 4 ). Both collections were on Mimulopsis solmsii (Acanthaceae) , which is also a food plant for C. proxima proxima .

Leaf shelters Ovum

The eclosed ova associated with stage 1 shelters of the two caterpillars that were reared were rounded, flattened on the bottom, 0.86 mm diameter, and although almost smooth, had around 40 very fine ribs becoming irregular near the top of the ovum.

Caterpillar

The caterpillars were not distinguished from those of C. proxima proxima , and although no details were recorded, a final instar caterpillar was photographed ( Figure 4 ). Head capsules measured 2.9 x 2.8 mm final instar, 1.96 x 1.94 mm penultimate instar, and 1.33 x 1.31 mm n–2 instar, wide x high. Although the head capsule seems the same as that of C. proxima proxima , the body is less translucent, having an overall paler appearance, perhaps due to, or partly due to, the underlying fat bodies. Further collections are needed to confirm that this is a specific difference rather than an individual one.

Pupa

No details were recorded, except that both pupae took 12 days to emerge. Examination of the emerged pupae showed them to be very similar those of C. proxima proxima . Based on limited material, the central frontal projec-

forwards ( Figures 1.3–5 ). There also appear to be subtle differences around the cremaster, but I would want to examine more material before concluding that these were consistent differences.

Figures

FIGURE 1. Frontal plates of pupae of Celaenorrhinus proxima group. 1, C. plagiatus female, collected as final instar caterpillar on Brillantaisia lamium, Forêt de Yapo, 4 Dec 1988, 88/203A. 2, C. undescribed nr. dargei male, collected as caterpillar on Mimulopsis solmsii, Kakamega Forest, 16 Jun 1991, 91/35. 3, C. proxima proxima female, collected as pupa on M. solmsii, Kakamega Forest, 1 Sep 1987, 87/20. 4, C. proxima proxima male, collected as caterpillar on Phaulopsis imbricata, Kakamega Forest, 19 Jul 1990, 90/75. 5, C. proxima proxima female, collected as caterpillar on?Acanthopale sp., near Douala airport, Cameroon, 16 Jun 1990, 90/205A. 6, C. proxima maesseni male, collected as caterpillar on unidentified Acanthaceae, Forêt de Yapo, Côte d’Ivoire, 4 Dec 1988, 88/202A (the projection over the eye on the left is crushed out of alignment).

FIGURE 2. Food plant and caterpillar probably of Celaenorrhinus plagiatus but perhaps of C. proxima maesseni. 1, flowering Ruellia primuloides, 4 Dec 1988, Forêt de Yapo, Côte d’Ivoire. 2, final instar caterpillar dorsolateral view, collected 4 Dec 1988 on R. primuloides, Forêt de Yapo, Côte d’Ivoire; photographed 6 Dec; parasitized by Apanteles (s.l.) sp. 9 Dec; 88/208A.

FIGURE 3. Celaenorrhinus undescribed species near dargei. 1, feeding on Justicia flava, Kakamega Forest, 6 Apr 1990. 2, from below, at rest on leaf, Kakamega Forest, 21 Sep 1991.

FIGURE 4. Celaenorrhinus sp. undescribed nr. dargei, collected as n–1 caterpillar on Mimulopsis solmsii, Kakamega Forest, 7 Jul 1991; moulted to final instar 1 Jul; photographed 7 Jul, 23 mm; pupated 17 Jul; 91/39B. 1, lateral view with anterior view of head. 2, detail of head, lateral view.

FIGURE 5. Details of final instar caterpillar head capsule and pupa of Celaenorrhinus undescribed nr. dargei, collected as n– 2 caterpillar on Mimulopsis solmsii, Kakamega Forest, 16 Jun 1991, pupated 31 Jul, adult male 12 Aug, 91/35. 1, anterolateral view of head capsule to show detail of microsculpture. 2, dorsolateral view of thorax. 3, dorsolateral view of abdomen showing spikes on anterior margin. 4, frontal view of frontal plate of pupa, with projections, those over the eyes angled at about 45°. 5–7, cremaster, ventral, lateral and dorsal views.