Intraguild predation of Planococcus ficus parasitoids Anagyrus pseudococci and Leptomastix dactylopii by Nephus kreissli

Abstract

Intraguild predation of the mealybug parasitoids Anagyrus pseudococci (Girault), and Leptomastix dactylopii Howard (Hymenoptera: Encrytidae) by Nephus kreissli Fürsch & Uygun (Coleoptera: Coccinellidae) was studied. The latter is a native predator of the important pest Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae) on grapevines in Turkey. For this purpose, P. ficus of different ages parasitised by A. pseudococci or L. dactylopii, or by both A. pseudococci and L. dactylopii, were served to fourth instars and adults of N. kreissli as food. Experiments were conducted using two different treatments: no-choice (served unparasitised or only one stage of parasitised mealybug) and choice (served unparasitised and only one age of parasitised mealybug together), under controlled environmental conditions. Both fourth instars and adult predators were fed on two- and four-day-old mealybugs parasitised by A. pseudococci or on two-, four- and six-day-old mealybugs parasitised by L. dactylopii or by either A. pseudococci or L. dactylopii. The predators could not consume six-day-old mealybugs parasitised by A. pseudococci, eight-day-old mealybugs parasitised by L. dactylopii, or those parasitised by either of these parasitoids which had become mummified. While it was found that the adult predators preferred parasitised mealybugs to unparasitised, the larvae did not show a pronounced preference between parasitised and unparasitised mealybugs (except for mealybugs parasitised by A. pseudococci).

Keywords:

• biological control
• consumption
• intraguild predation
• parasitoid
• predator
• vine mealybug

Acknowledgements

This research was supported by Ankara University BIYEP (Scientist Training Project) Program. We are grateful to Professor Dr. Muhip Özkan and Research Assistant Rabia Albayrak (Ankara University, Faculty of Agriculture, Department of Animal Science, Biometry and Genetics Unit) for their kind help in the statistical analyses. We would like to thank Dr M. Bora Kaydan (University of Çukurova) and Dr Juang-Horng Chong (University of Clemson) for their helpful reviews of this manuscript.