Pteroteinon laufella Hewitson 1868

Pteroteinon laufella Hewitson, 1868 (in Hewitson 1867 –1871)

Hewitson (1867 –1871) described Hesperia laufella from Akwa Akpa (=Old Calabar, south-eastern Nigeria), and it is known from Sierra Leone, east to Cameroon, and south to northern Angola and adjacent DR Congo (Larsen 2005). Larsen (2005) had no records from Benin, but many have since been collected there by A. Coache (T.B. Larsen pers. comm. 2013) and MJWC has a male from Cotonou (29 May 1989). There is a limited literature on it as a pest of oil palm in West Africa.

Food plants. As early as 1919 and 1929, this species was already appearing in German texts as a pest of oil palm in Cameroon (Lepesme 1947). As discussed in Cock (2010a) early reports of Pyrrhochalcia iphis (Drury) and Coeliades bixae (Linnaeus) (Hesperiidae, Coeliadinae) feeding on palms are likely to be misidentifications for Pteroteinon laufella.

Thereafter, Pteroteinon laufella reappears in the economic literature for French West Africa. As discussed above under Zophopetes cerymica, Mariau & Morin (1974) report on two hesperiid defoliators of oil palm and coconut: Zophopetes cerymica (as Z. dysmephila) and P. laufella, but do not separate the two in their account of the damage, economic thresholds, and natural enemies. Mariau et al. (1981) and Mariau (2000, 2001) summarise information on P. laufella as a pest of oil palm and coconut. In Côte d’Ivoire, Vuattoux (1999) reared this species primarily from oil palm (Presque tous les adultes obtenus ont été élevés sur Elaeis guineensis), and only two specimens from coconut; these two food plants are repeated in Vande weghe (2010).

Life history. The published life history information (Mariau & Morin 1974, Mariau et al. 1981, Herder et al. 1994, Mariau 2000, 2001) lacks detail, but does include some photographs. The ova are laid in batches; Mariau et al. (1981) show a batch of 17 ova, which have a dark dorsal circle around the micropyle.

The caterpillar is illustrated in black and white in Mariau & Morin (1974), Mariau et al. (1981) and Herder et al. (1994), and in colour in Mariau (2000), which is reproduced here as Figure 50.3. The head is black with a broad brown stripe from vertex to clypeus, narrow at the vertex and widening evenly to include the adfrontals and part of the adjacent epicranium ventrally; conversely, Mariau & Morin (1974) describe the head of the caterpillar as golden brown (like Z. cerymica) with broad brown patches on the sides (avec de larges taches brunes sur les côtés). T1 white, black pronotum in the posterior half; spiracle conspicuous, orange-brown; legs black and white. Body greenish white; spiracles pale brown; legs brown; prolegs not visible. The pupa is dark in colour, with a distinctive bifurcate frontal projection (Mariau & Morin 1974, Mariau et al. 1981), similar to that of P. caenira (Figure 45.1–2).

Natural enemies. Mariau & Morin (1974) do not distinguish between P. laufella and Z. cerymica, when they discuss the natural enemies of these two skippers. However, more recently, Mariau (2001) treats all the same natural enemies under P. laufella and mentions none for Z. cerymica, so we follow this arrangement here. Although these two palm-feeding skippers may well have natural enemies in common, this should not be assumed. The ova are parasitized by a Tetrastichus sp. and the pupae are host to tachinids, an ichneumonid and two chalcids: Brachymeria sp. and Stomatocerus sp. As discussed in Cock (2010a), the true host of the egg parasitoid Telenomus thoas Nixon (Scelionidae), described from ova of Pyrrhochalcia iphis, is probably Pteroteinon laufella.

Pathogens have also been recorded. In outbreaks, mortality due to two virulent RNA viruses can be high (Herder et al. 1994) and pupae may be killed by a Paecilomyces fungus (Mariau et al. 1981).

Economic damage. See under Z. cerymica, regarding the comments in Mariau & Morin (1974), Mariau et al. (1981) and Mariau (2000), which treat P. laufella and Z. cerymica together. Herder et al. (1994) refer to regular outbreaks of P. laufella on oil palm in southern Côte d’Ivoire.