How diverse are West African forests compared to those in Central and East Africa? A simple question but just a few years ago, the basic data to answer it for pholcid spiders were simply lacking.

West Africa could have been predicted to be less diverse than Central Africa, both for historical and current reasons (only about 12% of the original tropical moist forests remain in West Africa, as opposed to 59% in Central Africa). West Africa could also have been predicted to be less diverse than East Africa with its wider range of altitudes, its mosaic of different vegetation zones, and its highly diverse Eastern Arc.

Kakum Forest, Ghana, photo B.A. Huber

But was this also true for pholcid spiders? With the available publications and the pholcid material in existing collections it seemed impossible to even roughly estimate basic data like species numbers and distribution patterns.

For this reason, and in order to obtain comparable data across the African continent, I conducted a series of six expeditions (2008-2013) to East Africa (Kenya, Uganda), Central Africa (Cameroon, Gabon), and West Africa (Guinea, Ghana). This paper summarizes the data on West Africa, complementing revisions of all major taxa in the area (Huber, 2011b, 2012, 2013) and a previous summary on East African Pholcidae (Huber & Warui, 2012). The final part of this trilogy (Central Africa) was published in 2013 (Huber et al. 2013).

A main result of the present paper: with respect to Pholcidae, West Africa is indeed only about half as diverse as regions of comparable sizes in Central and East Africa.

Some of the species listed/described: 1. Pholcus doucki Huber, 2011 from Doucki, Guinea. – 2-3. Pholcus kakum Huber, 2009 from Forêt Classée de Ziama, Guinea (2) and Kakum N.P., Ghana (3). – 4. Leptopholcus kintampo sp. nov. from Kintampo, Ghana. – 5. Leptopholcus tipula (Simon, 1907) from Kakum N.P., Ghana. – 6. Nyikoa limbe Huber, 2007 from Kakum N.P., Ghana. – 7-8. Pehrforsskalia conopyga Deeleman-Reinhold & van Harten, 2001 from Atewa, Ghana. – 9-10. Anansus atewa sp. nov. from Atewa, Ghana. – 11-13. Spermophora akwamu sp. nov. from Kakum N.P., Ghana (13: web). Photos BAH.