Journal of Entomological Research

Average larval and pupal density of diamondback moth during kharif 2024 ranged 19.40 to 42.34 and 7.08 to 14.83/10 plants respectively during 25 -30th standard week followed by a sharp decline thereafter. Statistically significant difference between numerical density of larvae and pupae was observed (t = 6.70**; d.f. = 18; p = < 0.001) during entire observation period. Field parasitization of DBM by Cotesia plutellae and Diadegma semiclausum ranged 3.32 -33.29 and 1.67 to 42.87% during 27th to 33rd standard week, which declined to a minimum of 2.50 and 8.41% respectively on 40th standard week. Cumulative parasitism by C. plutellae and D. semiclausum during peak period was found as 76.02%. Difference in field parasitism by the two parasitoids was found statistically significant (t = 1.82*; d.f. = 26; p = 0.080) which indicated pre dominance of D. semiclausum. Larval and pupal densities of DBM exhibited strongly positive correlation with temperature whereas strongly negative correlation with relative humidity. Immature stages of DBM showed non significant positive correlation with individual or total parasitism. Temperature ranging 30 - 34°C was found favourable for parasitism. D. semiclausum showed dominance over C. plutellae in terms of higher rate of parasitism and its adaptation to cooler environments of temperate hilly areas of Kashmir.