REPRODUCTIVE BIOLOGY AND EGG PARASITOIDS OF PHILAENUS SPUMARIUS

The control of Philaenus spumarius (Hemiptera: Aphrophoridae), the main vector of Xylella fastidiosa, currently relies on measures against nymphs and adults. We studied the reproductive behavior of this insect and its egg parasitoids with the aim of providing new targets and approaches for control strategies against the vector. Main investigations intended to describe: i) a molecular marker of the reproductive phase in females, ii) the duration of ovarian parapause and timing of egg maturation in different climatic areas, iii) the variations in association with the symbiotic bacterium Wolbachia, iv) egg parasitoid communities. The results showed that: i) the expression level of the vitellogenin gene is a good marker of egg development phase, ii) the maturation of eggs and the duration of the ovarian parapause is highly dependent on the environmental conditions, iii) the prevalence of Wolbachia is highly variable among populations and seems to follow an increasing trend toward colder areas, iv) egg parasitoids [Ooctonus spp. (Hymenoptera: Mymaridae)] are present in both North and South Italy. These results start shedding light on some poorly known biological aspects of P. spumarius, thus providing useful information for designing new and more effective control strategies that take into consideration the reproductive biology of the main vector of X. fastidiosa.