Pa. Shah et al., SURVIVAL AND MORTALITY OF GRASSHOPPER EGG PODS IN SEMIARID CEREAL CROPPING AREAS OF NORTHERN BENIN, Bulletin of entomological research, 88(4), 1998, pp. 451-459
Surveys of egg pods of agriculturally important grasshoppers were carr
ied out in northern Benin between 1992 and 1995. Searches were made of
oviposition sites under shrubs of the perennial legume Piliostigma th
onningi along field margins. Ln 1993 and 1995, surveys were extended t
o include sorghum, Sorghum bicolor, and the perennial thatch grass Vet
iveria nigritana. The four principal grasshopper species found at thes
e oviposition sites were Hieroglyphus daganensis Krauss, Cataloipus fu
scocoeruleipes Sjostedt, Kraussaria angulifera (Krauss) and Tylotropid
ius gracilipes Brancsik comprising 86% of 4545 identified egg pods whi
le 651 egg pods could not be identified to species level. Predation by
meloid beetles (Epicauta, Mylabris and Psalydolytta spp.) varied betw
een 0 and 50% for the four dominant grasshopper species. From 1993 and
1994 data, nymphal eclosion from egg pods damaged by meloids was sign
ificantly lower than emergence from undamaged egg pods. The hymenopter
ous parasitoids Scelio africanus Risbec and S. mauriticanus Risbec wer
e reared from the four dominant grasshopper species and parasitism lev
els of 0.0-3.3% were recorded from these hosts. There were significant
differences in nymphal emergences between parasitized and unparasitiz
ed egg pods of H, daganensis.