Comparative biology of chlorantraniliprole selected and unselected Chrysoperla carnea (Stephens) populations: Stability of resistance, inheritance mode, and realized heritability.

Insecticide resistance in natural enemies can be used as a positive trait in integrated pest management programs by increasing the compatibility of two important tools; biological and chemical control. In this experiment, a field population of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) was selected with chlorantraniliprole for 35 generations (Chlor-Sel) developed a 100.32-fold resistance level compared to an unselected population (Unsel). The dominance values of resistance for reciprocal crosses confirmed incomplete dominance inheritance of chlorantraniliprole resistance. The results on projected rate of chlorantraniliprole resistance showed that at 10 % to 90 % survival in each selection and a realized heritability value of 0.19, the Chlor-Sel will require only 3 to 26 generations (Slope = 1.15) to increase a 10-fold level of resistance. The results of the age-stage life table experiment showed that fecundity, oviposition days, male and female longevity, net reproductive rate (Ro), and gross reproductive rate (GRR) of both crosses were significantly increased compared to their parents. The fecundity of reproductive females, male and female longevity, Ro, generation time (T), and GRR of Chlor-Sel were not significantly different than that of the Unsel strain of C. carnea. In conclusion, chlorantraniliprole resistance in C. carnea has an autosomal, polygenic, and incompletely dominant inheritance mode and C. carnea has potential to develop resistance that leads to fitness benefits. This information will help in management of insect pests by deploying resistant strains with selected insecticides and conservation of these natural enemies in fields with sustaining resistance genes.