Effect of parasitized prey on prey consumption, survival, growth, and development of Coccinella septempunctata L. (Coleoptera: Coccinellidae) under laboratory conditions

A study of interactions among natural enemies is important to develop a better biological control program. Among these interactions, one that is crucial is the consumption of parasitized prey by a predator. Feeding on aphid mummies could affect the predator as well as the parasitoid species. In this study, the effect of parasitized prey on prey consumption, survival, growth, and development of 4th instar larvae of the predatory species, Coccinella septempunctata L. (Coleoptera: Coccinellidae), as an active predator of aphids, was studied. Moreover, the effect of parasitized and mummified aphids on female fecundity was also evaluated. The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae) was used. Obtained results showed that the parasitized aphids, as a predatory food, significantly affected the predator. The prey consumption was highest on parasitized (24.10 ± 0.53) and lowest on mummified (9.75 ± 0.40) aphids. The survival rate was in the order of non-parasitized > parasitized > mummified. The mass gained by the 4th instar larvae of C. septempunctata was in the order of parasitized (26.25 mg ± 0.89) > non-parasitized (19.25 mg ± 0.86) > mummified aphids (10.20 mg ± 0.52), when fed on different prey. Developmental time of the predator was recorded highest, when it consumed mummified aphids (13.6 ± 0.39). As well, female fecundity was affected positively. The female was observed to lay the most eggs (323.55 ± 1.57) to have the highest number of hatched eggs (38.70 ± 0.92), and to have the highest egg mass (196.10 μg ± 1.22), when it consumed the parasitized aphids in contrast to non-parasitized and mummified aphids. It was also found that the type of prey did not affect the incubation period of the eggs.