The habitat functions of vegetation in relation to the behaviour of the desert locust Schistocerca gregaria (Forskal) (Acrididae: Orthoptera) - a study in Mauritania (West Africa)
The functions of vegetation for the behaviour of gregarious desert locust hoppers (Schistocerca gregaria [Forskal]) are considered in respect to different scales: single plant (taxon, life form), plant community (species composition, dominance, density), and patterns in vegetation and landscape. In the semi-desert of Mauritania, two typical desert locust habitats are phytosociologically characterized. The perennial communities of the tree and shrub layer belong to the alliance Acacio-Panicion with an oceanic Euphorbia balsamifera-Salvadora persica community in a dune-wadi complex characterized by Zygophyllum waterlotii, and a more continental Acacia ehrenbergiana-Panicum turgidum community in the inselberg landscape of the Mauritanides. The spatial-temporal movement of a hopper band was observed. Hopper band movement depends mainly on wind direction, but is also influenced by patterns in vegetation and landscape morphology. Places giving protection and for moulting are provided by perennials and dense vegetation patches. Length of stay is determined by predation, moulting and food availability. Feeding behaviour in the natural habitat depends on food plant preference and the availability of palatable plant species within the plant community. In this study, feeding damage is evaluated both qualitatively and quantitatively using the method Density Analysis with Estimation of Feeding Damage.