T. G. Shanower ¹, V. Anitha ¹, V. R. Bhagwat ¹, H. Dreyer ²

Affiliations
1 Crop Protection Division, International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502 324, Andhra Pradesh, IN
2 International Institute for Tropical Agriculture (IITA), Plant Health Management Division, B.P. 08-0932, Cotonou, BJ

Abstract

Clavigralla spp. (Hemiptera: Coreidae) eggs are laid in
clusters. Field collections at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) over three seasons from 1992-93 to 1994-95 showed that cluster size ranges from 2 to 62 eggs with a mean of 17.7 eggs. A majority of egg clusters (72%) contained between 7 and 24 eggs. Gryon clavigrallae Mineo (Hymenoptera: Scelionidae) parasitized up to 69 per cent of eggs and up to 100 per cent of egg clusters each season. Overall, more than 39 per cent of Clavigralla spp. eggs were parasitized by G. clavigrallae. The percentage of egg clusters parasitized and the percentage of eggs parasitized in a cluster were positively correlated with the size of the egg cluster. The percentage of eggs and egg clusters parasitized by G. clavigrallae increased through the season.

Keywords

Clavigralla spp., Egg Cluster Size, Egg Parasitoids, Gryon clavigrallae.

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J. Romeis ¹, O. Romeis ¹, T. G. Shanower ¹

Affiliations
1 Crop Protection Division, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh 502 324, IN

Abstract

Several ant species are reported to be important predators of insect pests (Way and Khoo, 1992; Veeresh et al.. 1995). In East Africa, ants were found to be important natural enemies of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) (Van den Berg and Cock, 1993a, b), one of the most serious pests in the Old World (Reed and Pawar, 1982).

Keywords

Paratrechina longicornis, Helicoverpa armigera, Pigconpea, Egg Predator.

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