The Senegalese grasshopper Oedaleus senegalensis Krauss.
Abstract
The following is based on the author's summary of this account of the distribution and biology of. Oedaleus senegalensis (Krauss), which is based on the literature, unpublished reports, and specimens in the collections of the British Museum and the Anti-Locust Research Centre. O. senegalensis is distributed over much of Africa north of the equator, the Middle East and the Indian sub-continent. It usually occurs at very low densities, but both hoppers and adults have been recorded at very high ones. It may cause considerable damage in cultivated areas, especially to graminaceous crops. From records of the habitats in which it has been found, it appears to favour semi-arid areas and to have a preference for ovipositing in light or sandy soils. It is frequently found on fallow land, which, with its preference for graminaceous plants, makes it potentially dangerous as a pest in areas of agricultural expansion. Observations on its life-cycle, though very limited, indicate that throughout most of the southern part of its distribution area (that is, in the tropical summer-rainfall areas), there are generally two generations a year, produced during the summer months. The species survives the dry winter period in the egg stage, and the first hatch of the year occurs with the first heavy rains. In the cooler, more northerly parts of its distribution area (that is, in the winter-spring rainfall areas of the sub-tropics and middle latitudes), the incidence of hopper and adult records indicates that there is only one generation a year, the eggs remaining quiescent through the dry late summer months and the cool winter months and hatching in spring and early summer. Characters distinguishing the adult of O. senegalensis from those of other species are given, and the egg-pod is described.