Variation in resistance of Vigna radiata var. radiata and Vigna radiata var. sublobata against Callosobruchus spp.: Implications for sustainable pest management

This study investigated the interaction between Callosobruchus spp. [ Callosobruchus analis (Fabricius), C. chinensis (Linnaeus), and C. maculatus (Fabricius)] and Vigna genotypes [ V. radiata var. radiata and V. radiata var. sublobata ] with differential resistance levels, using insect fitness bioassays and life table studies. Among the Vigna genotypes evaluated, the wild V. radiata var. sublobata (IC277039) exhibited strong resistance against all three Callosobruchus species, showing a Mean Development Time (MDT) and susceptibility index (SI) of 0. In contrast, V. radiata var . radiata genotype (V2802), resistant to C. maculatus and C. chinensis , exhibited susceptibility to C. analis . Further, the results revealed significant differences among Callosobruchus spp. in their life history traits across Vigna genotypes. Among the tested species of Callosobruchus , C. analis exhibited the highest virulence; Net Reproductive Rate (R 0 ) of 21.8 on NM94; 16.26 on IC322299 and 8.98 on V2802 genotype, posing a substantial risk to stored pulses. The strong resistance observed in Vigna radiata var. sublobata (IC277039) against Callosobruchus spp. highlights the need for further investigation into its molecular and biochemical mechanisms of resistance for developing sustainable strategies for storage pest management. • Callosobruchus spp. exhibited significant differences in their resistance against Vigna genotypes. • Vigna radiata var . sublobata (IC277039) demonstrated strong resistance to the three species of Callosobruchus . • C. analis exhibited highest virulence against the Vigna genotypes, posing a substantial risk to stored pulses. • Vigna radiata var . sublobata (IC277039) with strong resistance can be incorporated in pulse beetle management programs.