Drosophila suzukii and Tuta absoluta are successful biological invaders of agroecosystems. Their integrated pest management (IPM) programs involve the release and/or conservation of natural enemies. Among these, Ganaspis kimorum is a major Asian parasitoid of D. suzukii and has been introduced as a classical biological control agent of this pest in Europe and North America, while Necremnus tutae is a key fortuitous parasitoid of T. absoluta in the Mediterranean region. Bioinsecticides represent key alternatives to chemicals for controlling both pests. This study investigated the potential compatibility of both parasitoids with Beauveria bassiana, Bacillus thuringiensis, garlic essential oil (EO), and spinosad, in comparison to two synthetic insecticides, cyantraniliprole and chlorantraniliprole. The results showed that combining each of the tested insecticides with G. kimorum slightly increased pest mortality compared to the insecticide alone. Necremnus tutae had a significant additive effect on host mortality when combined with insecticides. Beauveria bassiana and B. thuringiensis were most compatible with both parasitoid species. Both garlic EO and chlorantraniliprole impaired the survival of immature N. tutae and showed sublethal toxicity on the reproductive and non-reproductive behaviors of N. tutae. Spinosad exhibited high acute toxicity on both juvenile and adult parasitoids of both species. Overall, these findings provide useful insights into insecticide selectivity toward two key parasitoids and offer new knowledge on the potential of combining natural enemies and bioinsecticides for optimized IPM.

Among hazelnut phytophagous insects, the box bug Gonocerus acuteangulatus is a key pest in Southern Italy that severely compromise the production of healthy hazelnut fruits with severe economic losses. Currently, the box bug is controlled by many chemical control methods, but biological control could represent a promising tool. An intensive monitoring program of G. acuteangulatus egg parasitoids in five Sicilian organic hazelnut orchards was carried out. Adults, nymphs, and eggs (parasitized and non-parasitized) of G. acuteangulatus were collected. Moreover, hazelnut fruit samples were observed to assess fruit damage. Five parasitoid species emerged from G. acuteangulatus eggs: Anastatus bifasciatus, Hadronotus bosellii, H. muscaeformis, Trissolcus belenus, and Ooencyrtus sp. Anastatus bifasciatus was the most widespread species, followed by H. bosellii. The highest parasitoid diversity occurred at mid-elevation sites. Fruit damage remained substantial, indicating that natural parasitism may not provide satisfactory pest control. Here, field emergence of T. belenus from G. acuteangulatus eggs demonstrates a host association historically reported as T. grandis. Therefore, this study updates and expands the parasitoid assemblage associated with G. acuteangulatus by revisiting historical records with contemporary field evidence for future augmentative or conservation biocontrol program against the box bug.