Observations on the biology of Afrotropical Hesperiidae (Lepidoptera) principally from Kenya. Part 4. Hesperiinae: Aeromachini and Baorini Author Cock, Matthew J. W. Author Congdon, Colin E. text Zootaxa 2012 3438 1 42 journal article 44508 10.5281/zenodo.246331 8bc74a10-7de0-4e39-8fc6-142a14d01b07 1175-5326 246331 Borbo fatuellus fatuellus Hopffer, 1855 ( Figures 17–18 ) Subspecies fatuellus occurs throughout sub-Saharan Africa and in Yemen , and additional subspecies have been described from São Thomé and the Comoros ( Evans 1937a , Larsen 1984 ). A form with grey scaling on the UNH ( cinerea Holland ) has been associated with the dry season in eastern and southern Africa ( Evans 1937a ) and both forms are common in Kenya . Van Someren (1939) reports B. fatuellus as fairly numerous in the grass and bush along the forest margins from 4,500–6,000 ft . ( 1370–1830 m ) in the Chyulu Hills, and it is not uncommon in the Makardara Forest ( Sevastopulo 1974 ). I consider it an occasional but widespread species of open forest throughout Kenya . TCEC has found it mainly in woodland in Tanzania , but extending into open areas in forest. Adult behaviour Adults settle low on grasses and shrubs when they are easily caught ( Dickson & Kroon 1978 ). These perches are used to maintain territories as described by Henning et al . (1997) , who note that adults also feed at flowers and damp patches. Food plants The recorded food plants are grasses. Le Pelley (1959) lists Cenchrus purpureus (= Pennisetum purpureum ) in Uganda , Forsyth (1966) gives Paspalum sp. and Zea mays (maize) in Ghana , and Sevastopulo (1975) lists Panicum trichocladum , C. purpureus (= Pennisetum purpureum ) and grasses generally from East Africa (this entry appears against both B. fatuellus and B. lugens , and I assume it applies to both). Sevastopulo (unpublished) does not mention Panicum trichocladum as a food plant, so the origin of this record is not clear. Vuattoux (1999) reared ten specimens in Côte d’Ivoire from several different grasses: five on Setaria barbata , two on Digitaria atrofusca (= D. seminuda ), one on Setaria megaphylla and two on unidentified grasses. Larsen (1991) lists Ehrharta , Oryza , Zea , Cenchrus (= Pennisetum ) and Panicum , but I have been unable to confirm Oryza from the literature. Ackery et al . (1995) list only Ehrharta , Cenchrus (= Pennisetum ), Panicum and Setaria . Later, Larsen (2005) lists Setaria , Cenchrus (= Pennisetum ), Panicum , Setaria and Digitaria ; he also reports his observation of oviposition on Imperata cylindrica in Nigeria . In South Africa , Murray (1959) , Pringle et al. (1994) and Henning et al . (1997) give Ehrharta erecta and Setaria megaphylla (= sulcata ) as food plants, while Dickson & Kroon (1978) also include “other grasses not specifically recorded”. I have reared B. fatuellus on Megathyrsus maximus (= Panicum maximum ) and another (non-flowering) grass in Kenya , and? Panicum ( s.l .) sp. in Côte d’Ivoire . TCEC raised a specimen from an ovum laid on an unidentified grass in a forest glade at Ambangulu in the West Usambaras, Jun 2001 . Leaf shelters Two 4–5mm n-2 caterpillars collected on an unidentified grass in Côte d’Ivoire (89/205B) made a two-cut shelter just before the leaf tip, by cutting two notches from the edge of the leaf, 25mm apart, and rolling the flap downwards to make a tube. The larger caterpillars shelter in a rolled leaf, and feeding is distal to this ( Henning et al . 1997 ). Caterpillar Clark (in Dickson & Kroon 1978 ) illustrates two different caterpillars of this species from South Africa . The first resembles one of those illustrated here (Figure 17.2); the second has the dark line in each half of the face narrower, and not extending basally, and the clypeus more extensively white. Henning et al . (1997) include a photograph of a caterpillar from South Africa , similar to that shown here as Figure 17.3–4. Although Clark (in Dickson & Kroon 1978 ) documents five instars, Sevastopulo (unpublished) recorded six at the Kenya coast. Up until the end of the penultimate instar, caterpillars have a plain, dark head; that of instar n-2 measured 1.2 x 1.2 mm (91/41). The head of the penultimate instar measures 1.8 x 1.9mm wide x high (n=2); it may be uniformly dark, but in one case (91/41) had diffuse slightly paler areas on the epicranium, in front of the stemmata and on the frons; body green with a white dorsolateral line and a diffuse pale lateral line (87/23). Only in the final instar do the caterpillars develop a variably marked black and white head ( Figure 17 ), 2.5 x 2.9mm wide x high (n=3). A description was prepared of a final instar caterpillar collected at Arabuko-Sokoke Forest on M. maximus (87/23), which measured 18mm when newly moulted and 37mm when mature. Head wider near base; slightly indent at vertex; dark brown; face white, with dark brown sutures, and a black line running from about half way between top of adfrontals and vertex, parallel to epicranium, meeting adfrontal suture a little below apex; basal part of this line then curves laterally and becomes more diffuse; a vertical line in basal half of clypeus (similar to Figure 17.4, but the brown line is narrower in the described specimen); scattered short, pale, erect setae. T1 concolorous with body. Body light yellowish green; dorsal line darker green, becoming translucent as the caterpillar matures; well marked pale dorsolateral and lateral lines, becoming more diffuse, as the caterpillar matures; ventrally, spiracles and all legs whitish. I recorded that the wax glands develop ventrally in the mature final instar caterpillar as a double patch on A8 and a single patch on A9 for one caterpillar (87/23, Arabuko-Sokoke Forest), on A5 and A6 for another (91/41, Kakamega Forest), and on A7–A8 for a third (89/205B, Côte d’Ivoire ); further observations are needed to clarify this. The final instar takes about 13 days. Development from eclosion to pupation can take 33 days at the coast (Sevastopulo unpublished). FIGURE 17 . Final instar caterpillars of Borbo fatuellus . 1 , dorsolateral view; collected as penultimate instar caterpillar on Megathyrsus maximus , Arabuko-Sokoke Forest , 28.ix.1987; moulted to final instar 2.x.; photographed 12.x., 37 mm; pupated 15.x., ref. 87/23; 2 , detail of head, anterolateral view; collected as n-2 caterpillar on unidentified grass, Kakamega Forest, 17.vi.1991; moulted to final instar 7.vii.; photographed 7.vii., pupated 18.vii.; 91/41; 3 , final instar, anterodorsolateral view, collected as small caterpillar on unidentified grass (? Panicum ( s.l .) sp.), Adiopodoumé, Côte d’Ivoire, 28.v.2005; moulted to final instar 17.vi.; photographed 17.vi., 22mm; pupated 30.vi.; ref. 89/205B. 4 , final instar, anterolateral view of head; details as 3. Pupa The pupa, typical of the group, is formed partially exposed in a leaf only partly rolled and held with silk basal and distal to the pupa ( Figure 18 ). The shelter is lined with white waxy powder, but this is not on the pupa itself. Male pupa 87/23 was 31mm long and about 5mm at the widest; slender, with a straight frontal spike 2.5mm long; light green; narrow subdorsal lines about 1mm apart. Pupation takes 10–19 days.