Using a kairomone-based attracting system to enhance biological control of mealybugs (Hemiptera: Pseudococcidae) by Anagyrus sp. near pseudococci (Hymenoptera: Encyrtidae) in Sicilian vineyards

Abstract

The “potato trap” technique was applied for the fi rst time in Italian (Sicily) vineyards in an attempt to assess: a) the impact of the kairomonal activity of the vine mealybug sex pheromone (S)-(+)-lavandulyl senecioate (LS) on the parasitism of mealybugs by the encyrtid Anagyrus sp. near pseudococci, b) the influence of two commonly used insecticides on the parasitization activity of A. sp. near pseudococci towards mealybugs, and c) the efficiency of the release of A. sp. near pseudococci in enhancing parasitism rates of mealybugs. The number of captured A. sp. near pseudococci females in LS baited traps was significantly higher than that in unbaited traps. The minimal number of days for the first parasitoid emergence in LS baited traps was almost 3 days earlier, compared to unbaited control, suggesting a faster host detection by the encyrtid when LS is applied. These findings resulted in a significant increase in parasitism of mealybugs by A. sp. near pseudococci in LS baited traps relative to unbaited traps suggesting that the LS is used by the encyrtid as kairomone to ensure greater potential for host searching activity. Insecticide treatments significantly affected parasitization activity of A. sp. near pseudococci on mealybugs when compared to an untreated control with parasitoid release. The buprofezin, chlorpyriphos-methyl and untreated control with no parasitoid release treatments had statistically similar numbers of emerged parasitoids from exposed mealybugs. The obtained results provide evidence that, in the absence of conventional insecticides applications, the use of the LS could be a promising tool to improve and strengthen biological control of mealybugs by A. sp. near pseudococci within Sicilian vineyard conditions.