Biotic and abiotic factors affecting the population dynamics of the Senegalese grasshopper, Oedaleus senegalensis

TL;DRAbstract

The Senegalese grasshopper, Oedaleus senegalensis (Krauss), is an important pest of graminaceous crops such as millet and sorghum. Evidence is presented to show that this species has an egg diapause, the induction of which is regulated both by the photoperiod and temperature experienced by females In northern Mali, 97–100% of eggs have broken diapause ca. seven months after oviposition and remain quiescent in the soil until post-diapause embryonic development is triggered by rain. Several egg-predator species prey on O. senegalensis, the most important one in northern Mali being the bombyliid Xeramoeba nr. oophaga (Zakhvatkin). The dry season survival strategy of this species differs from that of O. senegalensis in that emergence occurs after diapause termination, irrespective of soil moisture conditions. A population model based on the results of this study is described, illustrating a potential mechanism operating behind major O. senegalensis outbreaks. The model’s conclusions and pr

Chat with Paper

AI Agents for this Paper