In vitro evaluation of maize varieties on the development and reproduction of Chilo partellus (Lepidoptera: Crambidae)

In vitro experiments were conducted to evaluate the developmental and reproductive responses of Chilo partellus on different maize varieties in the Pesticide Toxicology and Application Technology Laboratory, Sindh Agriculture University, Tandojam. The maize stem borer, C. partellus, is a highly destructive insect pest that severely affects both fodder and cultivated crops worldwide. Although pesticides provide limited control of early infestations, they are ineffective against internal feeders and pose environmental risks. In contrast, utilizing resistant maize cultivars offers a sustainable, ecologically safe, and socially acceptable pest management strategy. The study revealed significant differences in the survival rates and developmental durations of C. partellus between hybrid and conventional maize under laboratory conditions. On conventional maize, the total developmental period ranged from 46.22 to 69.34 days (mean: 57.78 ± 11.56 days), whereas on hybrid maize, it ranged from 26.87 to 40.99 days (mean: 33.93 ± 7.06 days). Each developmental stage was shorter on hybrid maize. Females survived longer than males on both maize varieties, but their lifespan was notably shorter on hybrid maize. Regarding reproductive traits, C. partellus showed higher mean fecundity on conventional maize (604 ± 104.67 eggs, range: 500.11-709.44) compared to hybrid maize (302 ± 95.06 eggs, range: 207.44-397.56). Egg fertility was also significantly higher on conventional maize (mean: 55.44 ± 1.81%) compared to hybrid maize (mean: 24.61 ± 1.77%). Statistical analysis confirmed significant differences in developmental durations and reproductive traits between the two maize varieties. These findings highlight the potential of hybrid maize as a resistant cultivar against C. partellus.