Maize genotypes and resistance to rice weevil, Sitophilus oryzae (Coleoptera: curculionidae) and angoumois grain moth, Sitotroga cerealella (Lepidoptera: Gelechidae)

Abstract

Grains of eleven maize genotypes were evaluated for their comparative resistance to rice weevil, Sitophilus oryzae (L.) and Angoumois grain moth, Sitotroga cerealella (Oliv.) by ‘No choice’ method under laboratory conditions (28±2°C and 60±5% RH). Progeny of emerging adults, seed damage, weight loss of grain and susceptibility index were taken as parameters for this study. The results indicated that adult progeny of S. oryzae, seed damage and weight loss of grain were low in Shaktiman1 (41, 12% and 0.29%) and RHM 2 (40, 17.00% and 0.73%), respectively. High number of S. oryzae adults were developed in PEEHM 5 (228.00) followed by Shaktiman 2 (85.00) and incurred highest weight loss of grains. The same genotypes were screened against S.cerealella resulting highest moth emergence in VH 9 (63.00) followed by PEEHM 5 (58.50). Consequently the per cent seed damage and weight loss was high in PEEHM 5 (63.15, 14.27) and VH 9 (48.27, 10.13) while it was low in VH 4 (4.28, 2.74) followed by VH 5 (6.70, 2.86), respectively. The moderately susceptible genotypes were found to be Shaktiman 1 to S. oryzae while VH 4 and VH 5 to S. cerealella. However, none of the genotypes were found to be least susceptible to S. oryzae and S. cerealella. The correlation between adult progeny, seed damage, grain weight loss and susceptibility index with both species was significant and positive.