Andronymus caesar philander Hopffer, 1855

Cock, Matthew J. W. & Congdon, Colin E., 2013, Observations on the Biology of Afrotropical Hesperiidae (Lepidoptera). Part 5. Hesperiinae incertae sedis: Dicotyledon Feeders, Zootaxa 3724 (1), pp. 1-85 : 36-42

Andronymus caesar philander Hopffer, 1855

The central, East and southern Africa subspecies, philander , occurs in most damp forests in Kenya, but does not seem to extend much above 1600m. Sevastopulo (1974) considered it fairly common in Makardara Forest , Shimba Hills , throughout the year. In Tanzania this is a woodland butterfly up to 1500m, apparently absent from the northern highlands (Keilland 1990), although MJWC found it at Kitovu Forest on the Kenya-Tanzania border. Adults are only seen occasionally, but the caterpillars are readily found on flush growth of seedlings along paths and in clearings, where several individuals often occur on the same shoot .

Adult behaviour

MJWC observed an adult laying eggs on a sapling of Deinbollia borbonica in the middle of a shady track at the edge of the forest behind Diani Beach, 10 Dec 1990. This was obviously a favoured site as quite a number of ova and hatched ova were present, although no caterpillars could be found . MJWC has caught adults coming to flowers in Kakamega Forest .

Food plants

Aurivillius (1925) provides brief notes on the caterpillar and pupa, but does not give a food plant. Early records of recorded food plants include Sapindaceae and Fabaceae (Caesalpinioideae) ( Table 1 ).

In Kenya, MJWC found eggs and caterpillars on small plants (0.5–3.0m) of the tree Deinbollia borbonica (Sapindaceae) at Diani Beach and Kitovu Forest (91/03), and in Lower Meru Forest (90/32) on tree saplings of an unidentified species tentatively placed in Meliaceae (MJWC #86). Since only two species of Deinbollia occur in Kenya, and the second, D. kilimandscharica , only occurs above 1000m ( Beentje 1994), we conclude that Sevastopulo’s records from Deinbollia sp. in Kenya ( Sevastopulo 1974, and subsequent sources in Table 1 ) are referable to D. borbonica . In addition, there are parasitized remains ( Apanteles (s.l.) sp.) associated with this species in ABRI that were collected as a caterpillar on Lecaniodiscus sp. (Sapindaceae) at Kakamega Forest (S.C. Collins pers. comm.).

In Tanzania, TCEC found it on what appeared to be a Brachystegia sp. , feeding on lush, soft coppice growth on a roadside at Katuma, Mpanda, 19 Feb 1996; on Julbernardia globiflora at Mishamo, western Tanzania, May 1997; and on Pericopis sp. at Kihansi Gorge, Mar 2000 and Chivanjee Estate, Tukuyu, 20 Nov 2003 (all Fabaceae , Caesalpinioideae ).

Leaf shelters

Shelters for small caterpillars are made by cutting two notches from the edge of the leaf, and folding the resultant flap under ( Figure 41.1 ); additional feeding at one or both notches means that the shelter can be folded over further at one or both ends. As the caterpillar grows, the shelters gets correspondingly larger and longer ( Figure 41.1 ).

The pupa is formed in a specially prepared shelter ( Figure 41.2 ), similar in concept to that described for Acleros mackenii above. The pupal chamber is suspending by quite a long section of bared mid-rib, and the chamber itself is completely enclosed by the leaf remaining. Of the 17 eclosed pupae preserved in ABRI, two are preserved together with their complete leaf shelter. One is constructed with a leaf of about 80 x 50mm, oval, pointed apically; one half untouched, the other has been eaten from the margins and folded over upwards, the fold on midrib at basal end and a little away from midrib at distal end; the central area is about 30 x 12mm, with 6 irregular extensions of 4–11mm along the margin of the shelter lid; pupa with head distal. The other is on a leaf remains 42mm long, distally having been completely eaten; leaf flat at mid-rib, and folded over upwards a little to one side; the lower half of the leaf has been mostly eaten, with three irregular projections from mid rib in basal half of shelter; a central semi-oval 24 x 8mm, with six irregular projections of 6–12mm (photo); pupa with head distal.

Ovum

Ovum 1.0 x 0.75mm wide x high; chorion transparent, but due to the contents ovum appears pink, darker on the micropyle ( Figure 42 ); minutely sculptured with 29–30 fine ribs, more evident towards the base than the apex. Ova are laid on the leaf upper surface.

Caterpillar

The youngest instars are translucent green with a black head, but as they mature the body becomes increasingly white in colour ( Figure 43 penultimate instar).

In the striking fifth instar, the body is completely white, apart from a slightly darker dorsal line, a subdorsal dot in the anterior half and a dorsolateral dot in the posterior half of A1–7 ( Figure 44.1 ); and the head brown with yellow spots on epicrania and adfrontals, 3.0 x 3.3mm wide x high ( Figure 44.1 ). Caterpillars collected by TCEC in Tanzania show that the yellow markings of the head may be pale ( Figure 44.2 ), and the sutures each side of the adfrontals may be dark ( Figure 44.3–4 ). A single caterpillar collected on Pericopsis sp. at Kihansi Gorge had the head ground colour almost black ( Figure 44.5 ), but without further material we can only speculate as to whether this represents an extreme variation or a local population.

Pupa

The pupal shelter is similar to those shown for A. hero below ( Figure 49 ). As the pupa is more or less fully enclosed in its leaf shelter, it is not surprising that it is less well camouflaged ( Figure 45 ) than that of A. mackenii which is substantially exposed in its shelter ( Figure 43 ). The inside of the pupal chamber is lightly covered with a powdery white wax, but little of this is deposited on the pupa itself. The fore wing tips are slightly falcate, and the proboscis sheath extends 0.7mm beyond the tips. The pupal stage takes 16 days (range 14–17).

Natural enemies

The caterpillars from Lower Meru Forest were very heavily parasitised by an Apanteles (s.l.) sp. The Apanteles larvae emerge from the body of the mature fifth instar caterpillar after it has started construction of the pupal leaf shelter. Cocoons are arranged on each side of the corpse, in a loose mass; each cocoon is attached to the substrate by a short silk stalk at one end, and the other end sticks up. This is completely different to other Apanteles cocoons which MJWC have reared from Hesperiidae for which the cocoons are arranged loosely or neatly in rows with the cocoons parallel to and attached to the substrate. Out of 14 caterpillars from Lower Meru Forest which MJWC collected at the beginning of April 1990, nine grew to maturity, of which eight were parasitised, although only two batches of cocoons out of the eight successfully emerged. These comprised one batch of 59 cocoons, from which two males and 52 females emerged (90/32B), while the other batch comprised 50 cocoons, but only six females emerged (90/32A). The cocoons took about five days to emerge. A similar group of 29 cocoons reared from A. caesar collected on Lecaniodiscus at Kakamega, Kenya, is preserved in ABRI.

Discussion

Henning & Henning (1989) and Henning et al. (1997) include a description of the early stages, and the latter includes a photograph by R. Paré of the pupa. Although this photograph is a good match to the pupa shown here ( Figure 45 ), the description of the ovum, caterpillar and pupa do not match those described and illustrated here.

The only clear difference between the two subspecies is that philander ova have 29–30 ribs, whereas those of caesar have 36–41. The caterpillars and pupae are very similar and longer series of material would be required to assess whether the minor differences are consistent, but it seems unlikely.

Figures

FIGURE 41. leaf shelters of Andronymus caesar caesar. 1, Apical leaves of Deinbollia borbonica sapling, with two ova and eight leaf shelters, Kitovu Forest, 2 Apr 1990, 90/32; 2, Pupal leaf shelter on Deinbollia borbonica, 24 Jan 1991, 91/3A.

FIGURE 42. Ovum of Andronymus caesar philander collected on unidentified sapling, Lower Meru Forest, 2 Apr 1990; photographed 4 Apr; 90/32.

FIGURE 43. Penultimate instar caterpillar constructing shelter, collected 1–2 Apr 1990 on unidentified sapling, Lower Meru Forest; photographed 2 Apr 1990; moulted 4–6 Apr; 18mm; 90/32G.

FIGURE 44. Final instar caterpillar of Andronymus caesar. 1–2, collected on Deinbollia borbonica, 1–2 Apr 1990 on unidentified sapling, Lower Meru Forest; photographed 2 Apr; moulted 4–6 Apr; 18mm; dorsal view, 2 Apr, 90/32A; 2, detail of head, as 1; 3–4, collected on Pericopsis sp., Chivanjee Estate, Tukuyu, Tanzania, 20 Nov 2003, TCEC; 3, dorsal view; 4, dorsolateral view; 5, collected on Pericopsis sp., Kihansi Gorge, Tanzania, 11 Feb 2008 (TCEC).

FIGURE 45. Pupa of Andronymus caesar caesar. 1, dorsolateral view, collected on Pericopsis sp., Chivanjee Estate, Tukuyu, Tanzania; photographed 28 Nov 2003; TCEC; 2, dorsal view, collected as final instar caterpillar on unidentified plant (?Meliaceae), Lower Meru Forest, Kenya; pupated 8 Apr 1990; photographed 8 Apr; adult 22 Apr; 23mm; 90/32F; 3, lateral view, same as (1).

FIGURE 49. Pupa of Andronymus hero. 1, western population, collected as caterpillar on Combretum aphanopetalum, Fôret de Yapo, Côte d’Ivoire, 4. Dec 1988; pupated 9 Dec; photographed 13 Dec; eclosed 26–27 Dec; 26mm; 88/206; dorsolateral view; 2, eastern population, collected 25 Mar 1994 on Combretum sp., Kasye Forest, Kigoma, western Tanzania; photographed 2 Apr 1994; TCEC.