BackgroundIn sub-Saharan countries infested by tsetse flies, African Animal Trypanosomosis (AAT) is considered as the main pathological constraint to cattle breeding. Africa has known a strong climatic change and its population was multiplied by four during the last half-century. The aim of this study was to characterize the impact of production practices and climate on tsetse occurrence and abundance, and the associated prevalence of AAT in Burkina Faso.Methodology/Principal FindingsFour sites were selected along a South-north transect of increasing aridity. The study combines parasitological and entomological surveys. For the parasitological aspect, blood samples were collected from 1,041 cattle selected through a stratified sampling procedure including location and livestock management system (long transhumance, short transhumance, sedentary). Parasitological and serological prevalence specific to livestock management systems show a gradual increase from the Sahelian to the Sudano-Guinean area (P<0.05). Livestock management system had also a significant impact on parasitological prevalence (P<0.05). Tsetse diversity, apparent densities and their infection rates overall decreased with aridity, from four species, an apparent density of 53.1 flies/trap/day and an infection rate of 13.7% to an absence at the northern edge of the transect, where the density and diversity of other biting flies were on the contrary highest (p<0.001).Conclusions/SignificanceThe climatic pressure clearly had a negative impact on tsetse abundance and AAT risk. However, the persistency of tsetse habitats along the Mouhoun river loop maintains a high risk of cyclical transmission of T. vivax. Moreover, an “epidemic mechanical livestock trypanosomosis” cycle is likely to occur in the northern site, where trypanosomes are brought in by cattle transhuming from the tsetse infested area and are locally transmitted by mechanical vectors. In Burkina Faso, the impact of tsetse thus extends to a buffer area around their distribution belt, corresponding to the herd transhumance radius.

La falaise de Banfora est d'une grande richesse floristique et faunique. Ses forêts renferment des espèces endémiques mais aussi des espèces remarquables telles que Albiziadinklagei, Acridocarpus chevalieri ou Warneckea fascicularis qui ne se retrouvent nulle part ailleurs au Burkina Faso. C'est aussi le cas de certaines espèces d'insectes telles que Dicronorhina kouensis ou Stephanorhina guttata. Toutefois, ces forêts sont menacées, particulièrement autour de Bobo-Dioulasso où la faune d'origine a déjà partiellement disparu. Les sites de la falaise sont comparés entre eux ainsi qu'avec d'autres forêts de la région de Bobo-Dioulasso. Une très grande diversité biologique s'observe d'une forêt à l'autre. La dispersion des espèces suggère que ces forêts résulteraient de masses forestières plus vastes dont elles seraient les relictes. La végétation forestière des falaises aurait trois origines : la forêt dense sèche, caractérisée par Guibourtia copallifera, qui pourrait représenter le fond forestier originel avant l'invasion de la flore des savanes ; la forêt dense humide, représentée par la majorité des espèces ripicoles, qui serait issue de la masse forestière humide en suivant le réseau hydrographique ; un fond de flore montagnarde inféodé aux falaises gréseuses, dont l'unique représentant serait Warneckea fascicularis, auquel il serait possible de rattacher les espèces de rochers. La communauté de rongeurs des sites forestiers de la falaise de Banfora est un mélange d'espèces typiquement forestières (en particulier Praomys rostratus) dans les zones les moins perturbées et d'espèces très anthropophiles (comme Rattus rattus) sur les sites les plus dégradés par l'action humaine. La plupart des espèces d'insectes ont probablement pour origine la forêt humide de Côte d'Ivoire, avec des influences maliennes, comme Coeliades aeschylus, ou togolaises, comme Dicronorhina kouensis, espèces qui se rencontrent surtout en zone de savane guinéenne, à proximité des forêts galeries. Ces espèces n'étant pas observées au Sud, ni respectivement à l'Est et à l'Ouest du Burkina Faso, la falaise de Banfora pourrait constituer un point de rencontre entre différentes faunes, ce qui en fait toute la richesse. (Résumé d'auteur)

The Neuroleon species of sub-Saharan West Africa are reviewed. Eight species are recorded: N. drosimus Navás, N. lapidarius nov. sp., N. modestus (Navás), N. nubilatus (Navás), N. rapax nov. sp., N. raptor nov. sp., N. pardalice (Banks), and N. ruber nov. sp. A ninth species, N. nigericus Navás, of which no specimens could be examined, is tentatively maintained in the genus Neuroleon pending examination of the type. Three new synonymies are established. Seven species are removed from the genus Neuroleon. N. pardalice is recorded from the region for the first time. The species are illustrated and keyed.

The genus Capicua Navás, 1921, synonymised with Geyria Esben-Petersen, 1920 by Stange (2004), is reinstated and redescribed. The unique specimen of Capicua fulvicauda Navás, 1921 kept in the Muséum d’Histoire Naturelle, Paris is designated as lectotype. Two new species of antlions from West Africa are described and tentatively included in Capicua pending more material of the type species C. fulvicauda to verify this placement. Holotypes and paratypes are deposited in the collection of CIRAD/CBGP in Montpellier, France.

The increase of human population, combined with climatic changes, contributed to the modification of spatial distribution of tsetse flies, main vector of trypanosomiasis. In order to establish and compare tsetse presence and their relationship with vegetation, entomological survey was performed using biconical traps deployed in transects, simultaneously with phyto-sociological study, on the Comoe river at its source in the village of Moussodougou, and in the semi-protected area of Folonzo, both localities in Southern Burkina Faso. In Folonzo, the survey revealed a diversity of tsetse with 4 species occurring with apparent densities as follows: Glossina tachinoides (8.9 tsetse/trap/day); G. morsitans submorsitans (1.8 tsetse/trap/day); G. palpalis gambiensis (0.6/trap/day) and G. medicorum (0.15 tsetse/trap/day). In Moussodougou, a highly anthropized area, mainly G. p. gambiensis was caught (2.06 tsetse/trap/day), and rarely G. tachinoides. The phyto-sociological study allowed discrimination of 6 types of vegetation in both localities, with 3 concordances that are riparian forest, shrubby and woody savannah. In Moussodougou, all tsetse were caught in the riparian forest. That was also the case in Folonzo where a great proportion (95 to 99 % following the season) of G. p. gambiensis and G. tachinoides were caught in the gallery, while G. m. submorsitans was occurring as well in the gallery as in the savannah, and G. medicorum in the forest gallery. This study showed that although G. tachinoides and G.p. gambiensis are both riparian, they do not have the same preference in terms of biotope.