J. HYM. RES. Vol. 3, 1994, pp. 5-16 A Survey of the Leaf Litter Ant Fauna in Ghana, West Africa (Hymenoptera: Formicidae) Robert Belshaw and Barry Bolton Biodiversity Division, Department of Entomology, Natural Historv Museum, Cromwell Road, London SW7 5BD, U.K. Abstract. — Leaf litter samples were taken from 34 sites scattered across the moist tropical forest zone in Ghana. They included areas of primary forest, secondary forest and cocoa. Over 40,000 individual ants were extracted using Winkler bags and identified. The species found are listed together with their abundance and a summary of their distribution. A total of 176 species was found (excluding stray workers of arboreal and surface-foraging species), almost two-thirds of which were Myrmicinae. The composition of the fauna is discussed and compared with that found in other tropical forests The species composition at the different sites showed little variation either between the different forest types or with geographic distance. INTRODUCTION In the West African forest belt there has been little quantitative sampling of the ant fauna; stud-ies have been carried out in the Tai Forest Reserve, Cote d'lvoire (see Levieux 1982 and included ref-erences) and the Reserve de Campo, Cameroun (Halle and Pacal 1992: 65-109). In Ghana there has been no quantitative sampling except in the main tree-crop, cocoa. This has been studied in detail (e.g. Majer 1976 and included references) but the extent to which it resembles the original forest fauna is not known. Nevertheless, this research has led to the taxonomy of West African ants being more advanced than that of most tropical ant faunas (e.g. Bolton 1987 and included references). In consequence we can survey elements of this fauna with the hope of accurately identifying much of it to species. Ghana has two main terrestrial biomes, sa-vannah and forest, and these have distinct ant faunas. In turn, the forest zone is readily divisible into a canopy and a ground fauna. In this paper we survey the leaf litter element of the forest ground fauna by sampling at different localities across Ghana. In addition to identifying the species present, we discuss the composition of the fauna and compare it with that from other tropical for-ests. We also examine how the species composi-tion at the sites varies geographically and between the different forest types. Voucher specimens of all taxa are deposited in the Natural History Museum, London. METHODS Sites. — The locations of the sampling sites in Ghana are shown in Figure 1, with brief descrip-tions and sampling dates given in Table 1. Sites designated by the same letter but with different numbers (e.g. jl and j2) are within 3km of each other. With one exception, the sites are within the moist semi-deciduous forest zone of Hall and Swaine (1976). We sampled in a wide range of the forest habitats found in Ghana, including 14 areas of primary forest (in the broad sense of forest with a closed high canopy), 10 areas of secondary forest (of varying age, mostly on agricultural land) and 10 cocoa farms. Sampling was carried out between December 1991 and November 1992. Sampling. — At each site an area of approxi-mately 1000m : was measured out. Within this area ten lm 2 quadrats were placed at random. All the leaf litter inside a quadrat was collected, shaken through a 1cm sieve, and then left for three days in a Winkler bag. The extracted ants were combined to form a single total for each site, each site being sampled on only one occasion. All sampling was done between 9.30 a.m. and 3.00 p.m. At three sites (h, ql and cj2) an additional soil
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