Effects of Host and Parasitoids Density on the Progeny Sex Ratio of Lipolexis Oregmae (Gahan)

The success of biological control programs depends on the mass propagation of high-quality parasitoids. For maximizing the female offspring, the knowledge of reproductive strategies and the factors affecting reproductive potential should be evaluated, which is essential in the biological control program. In the present study, the progeny sex ratio (PSR) of Lipolexis oregmae was investigated in Aphis gossypii reared on three host plants, Luffa aegyptiaca, Lagenaria siceraria, and Momordica charantia. The PSR was observed to be host plant-dependent and female-biased. The maximum PSR on the host plant of 100 aphids was observed on L. siceraria (0.363 ± 0.0245) and was lowest on L. aegyptiaca (0.28 ± 0.0113). L. aegyptiaca was a more suitable host plant, and the number of female progeny was higher than that of other plants. When the host density increases, the value of PSR decreases significantly. The maximum PSR value was recorded across all ten host densities of the three plants. The PSR of L. oregmae was parasitoid density-dependent, and the value of the PSR increased with the increase in parasitoid numbers. The maximum value was recorded for L. siceraria (0.39 ± 0.007), followed by M. charantia and L. aegyptiaca..