Shedding Light on Dasineura oleae Parasitoids: Local and Landscape Effects

Abstract

Dasineura oleae was considered a minor pest in olive orchards. However, in the last decade, outbreaks have been reported all over its distribution area. Little is known about D. oleae biological control strategies; therefore, investigations into the biology and ecology of D. oleae parasitoids are urgently needed. In this scenario, the present field study reported the flight period of D. oleae parasitoids, evaluating their relative abundance over other parasitoids living in olive orchards. Furthermore, it estimated the effect of local and landscape features on D. oleae parasitoids within the frame of the overall parasitoid community. Lastly, we aimed to provide useful insights into the effectiveness of parasitoids for D. oleae population management. Hymenopteran parasitoids were sampled using Malaise traps in six sampling sites in central Italy. Results showed that Platygaster demades was the most abundant D. oleae parasitoid. Its presence was associated with high rates of D. oleae parasitism. The abundance of this parasitoid was influenced by the abundance of seminatural habitats.

Spatial and temporal dynamics of soybean gall midge (Resseliella maxima) parasitism by Synopeas maximum

“…Our findings indicate that rates of parasitism by Synopeas maximum were higher in field edges than the field interior in 2021, but not in 2022 when parasitism was also detected in field interiors at the end of the season. A recent study on the parasitoids of the olive leaf gall midge, Dasineura oleae (Angelini), also showed no differences in the abundance of Platygaster demades Walker between the interiors and edges of the fields 41 . Despite the higher number of R. maxima in early August (mid‐season), very little parasitism was detected during this period in both years.…”

“…A recent study on the parasitoids of the olive leaf gall midge, Dasineura oleae (Angelini), also showed no differences in the abundance of Platygaster demades Walker between the interiors and edges of the fields. 41 Despite the higher number of R. maxima in early August (mid-season), very little parasitism was detected during this period in both years. Synopeas maximum was mostly detected in the fields in early July and then again in mid-August until early September (beginning and end of the season), while R. maxima was active from mid-June until early September.…”