Andronymus neander neander Plötz, 1884

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 : 46-48

Andronymus neander neander Plötz, 1884

Plötz (1884) described this species as Apaustus neander from Loango, which Ackery et al. (1995) give as in Democratic Republic of Congo (= Zaïre), but probably this should be Gabon (e.g. Purdy 1822). It occurs in the nominate subspecies from Senegal through West Africa (uncommon), central, East and southern Africa ( Evans 1937, Larsen 2005). Riley (1928) described A. thomasi Riley for the population on Sao Thomé, and Evans (1937) placed this as a subspecies of neander , hence the need for the trinomial for the mainland subspecies.

In Kenya, it is primarily found in coastal regions ( Larsen 1991) matching the restricted range of the known food plant Brachystegia spiciformis (below). However, given its propensity for mass movements (below) it could occur anywhere in the country, and this may be the origin of Neave’s (1904) record from Nyangori, north of Kisumu. MJWC has one specimen taken at light at Ndara Ranch, near Voi, but has not seen it further inland.

Adult behaviour

Most authors dealing with African skippers have recorded or commented on A. neander as a migratory species—or at least one that makes mass movements—including Holland (1896), Swanepoel (1953), Gifford (1965), Pinhey (1965), Lindsey & Miller (1965), Pinhey & Loe (1977), Dickson & Kroon (1978), Kielland (1990), Larsen (1991), Pringle et al. (1994), Henning et al. (1997), Larsen (2005), and Woodhall (2005). Migrations are primarily in eastern and southern Africa, whereas in West Africa, it seems to be A. gander Evans that indulges in mass movements rather than A. neander ( Fontaine 1988, Larsen 1995, 2005).

C.B. Williams, the pioneer of the study of insect migration, collected observations on actual migratory flights of A. neander ( Williams 1928, 1930a, 1930 b, 1933, 1937, Williams et al. 1942, Williams 1957, 1958). Later, he summarised his earlier publications and records regarding mass movements of this skipper in Africa, together with those of other authors ( Cookson 1958, Sevastopulo 1962, Handman 1963, etc.) and provides more detail of his observations at Amani, Usambara Mountains, Tanzania ( Williams 1976). At Amani, where C.B. Williams was resident in the late 1920s, he found that mass movements occurred in many but not all years, in March, April and sometimes the beginning of May, and that the direction of flight was almost entirely between the south and southwest. Williams observed the 1928 mass movement in some detail. This flight lasted for seven weeks, with the skippers moving SSW on every fine day. The peak occurred on 1 April 1928 when about 500 skippers per minute were passing on a 20 yard front. Males and females were represented in equal numbers. The skippers normally flew at a height of 1.3–2.0m, but at the edge of forest blocks slowly rose to 6– 9m. The flight was in channels of high concentration, rather than on a uniformly dense front, perhaps because the skippers flew around obstacles rather than over them. Based on a measured flight speed of 15–19 km /h, Williams extrapolated that these flights may have started from the Kenya Coast some three days earlier, and that if they continued, they would be in the vicinity of Lake Malawi ten days later. Williams (1976) listed mass movements at the Kenya Coast in March and April only: end of March 1911 near Rabai, flying to the NNE ( Rogers 1912); March 1930 near Malindi, flying to ‘a little south of west’ (R.M. Graham in Williams 1933); mid-April 1960 at Bumburi (=Bamburi), Mombasa, flying south ( Sevastopulo 1962).

Sevastopulo (1974) notes that A. neander "migrates through the Makardara Forest [Shimba Hills], sometimes present in vast numbers, sometimes absent. Recorded for all months except November." We interpret this as being present in all months, not migrating in all months. Dewhurst (1987) records a mass movement at the Kenya coast, which we quote in full, since the original is rather inaccessible: “On 6 January 1997, on the Dida to Roka road on the southern edge of the Sokoke Forest, what could only be described as a swarm of the Hesperid butterfly Andronymus (probably) neander Evans , was seen crossing the road at between 1 and 3 m high and flying from S.S.E. to N.N.W. at 14.50 h. There were so many butterflies flying so fast that it was impossible to count them. At the onset of a rain shower which lasted only a few minutes, all visible flight stopped, beginning again immediately the rain stopped.’ MJWC observed a modest mass movement in the Shimba Hills on 12 April 1990. Large numbers were seen flying towards the South across a front from Giriama Point (a headland on the coastal, east side of the hills) to Makadara Forest on the inland side (and perhaps on a wider front, but no observations were made to test this). At Giriama Point they passed at a height of 1–3 m at a rate of several a minute, and could be caught with some difficulty by a rapid overtaking shot with the net. In the Makadara Forest the skippers flew higher, at about 4– 5 m, and were channelled along a forest road at the rate of one every second or two (although no specimens were caught to confirm their identity).

Food plants

In north-west Zambia, Dollman (unpublished) reared this species from a leguminous tree ‘mutowo’, a species which was not identified scientifically in his notes. The only use of this vernacular name we have traced is that of Raynes (2007) who lists it as used in Zambia for Isoberlinia spp. (Fabaceae) .

The food plants according to Van Someren (1974) include Brachystegia randii (?) and B. spiciformis (Fabaceae) ; the ‘(?)’ after the first species indicates that the herbarium material was not adequate for certain identification (introduction to Van Someren 1974). MJWC has seen preserved early stages of Van Someren's material in the National Museums of Kenya (but not recorded details), so these records are presumably based on Van Someren’s own observations in East Africa. Brachystegia randii , described from Zimbabwe, is variously considered a valid name ( Tropicos 2012), an unresolved name ( The Plant List 2012) or a synonym of B. spiciformis ( Brummitt et al. 2007) . Given that these food plant records seem to be van Someren’s own observations from East Africa, where only B. spiciformis definitely occurs, it seems reasonable to treat these records as both referring to B. spiciformis .

Subsequent authors give the food plants as Brachystegia ( Sevastopulo 1974, 1975, Larsen 1991, Ackery et al. 1995, Heath et al. 2002, Larsen 2005) or B. spiciformis ( Kielland 1990) or ‘possibly’ B. spiciformis ( Woodhall 2005) . Pringle et al. (1994) also give the food plant as B. spiciformis , but specifically based on observations by R. Paré, whereas Henning et al. (1997) give the food plant as B. boehmii , a species of southern Africa, north to Tanzania and Congo ( Brummitt et al. 2007). In Côte d’Ivoire, Vuattoux (1999) reared this species on Afzelia africana (Fabaceae) (repeated in Larsen 2005). At variance with these records from Fabaceae, Heath et al. (2002) give Acridocarpus longifolius (= A. smeathmannii ; Malpighiaceae ) as a food plant (repeated in Larsen 2005), but we think this needs confirmation.

Life history

We have not reared this species, or found descriptions of the early stages. Although Dollman (unpublished) reared it, he did not paint the caterpillar. He noted that the leaf shelter was a ‘lightly spun cylinder—the larva resting on the dorsal surface of the leaf’. There is an emerged pupa from Dollman’s collection in the Dry Early Stages Collection of The Natural History Museum, London; it resembles the pupa of Andronymus caesar . As noted above, MJWC has seen preserved early stages of this species from the Van Someren collection in the National Museums of Kenya, but we have not had the opportunity to re-examine these for this account.