Despite their small size, insects and other invertebrates are the most important animals in the Atewa Forest. Some insects and other invertebrates include: termites, 76 species of dragonflies and damselflies, 711 different species of butterflies and moths, 61 species of bush crickets, and more. They provide a number of invaluable ecological services, such as pollination of plants, soil production and fertilization, removal of organic waste, and providing food for most vertebrates. Additionally almost all the insects and other invertebrates are completely harmless to humans, only very few species transmit diseases.
Atewa Forest is one of the most significant forests for butterflies in the region and has the richest butterfly population of any forest in Ghana (Larsen 2006). With 711 species, over 70% of Ghana’s entire butterfly fauna are thought to occur in Atewa Forest, making it probably the most diverse forest for butterflies in all of West Africa. At least two species are known only from Atewa Forest, the Atewa Dotted Border Mylothris atewa and nthene helpsi. An endemic subspecies – Acraea kraka kibi – is also confined to Atewa Forest. The celebrated African Giant Swallowtail Papilio antimachus also occurs.
Odonata (dragonflies and damselflies) were surveyed comprehensively in Atewa Forest in 2006 (McCullough et al 2007) and 76 species were recorded. Two others species have been reported (GBIF). None of these are known to be at risk of extinction. However, many of them are dependent on clear flowing water and are likely to have been affected by the impacts of galamsey in the neighbouring area.
37 species of katydids were recorded in Atewa Forest, also in 2006 (McCullough et al 2007). We were only able to locate 18 moth species recorded in Atewa Forest. The true number must be many hundreds if ratios with butterflies are as noted elsewhere. All other invertebrate species we found records of amounted to another 38 species including members of Trichoptera, Arachnida, Hymenoptera, Hemiptera, Diptera, Coleoptera and Gastropoda.
Of particular note, however, is the impressive arachnid, the Atewa Hooded Spider Ricinoides atewa (Figure 9). This was described in 2008 as a new species and named after the forest (Naskrecki 2008). It is largest know species of Tick Spider (ricinuleid), of which 11 of the world’s 60 species occur in West Africa