Temperature effects on the behavior of two egg parasitoids of Halyomorpha halys.

Halyomorpha halys is an invasive, highly polyphagous pest causing severe damages to agricultural cropping systems worldwide. Currently, chemical control is the most adopted management tactic to counteract the economic losses deriving from the brown marmorated stink bug feeding damages, often disrupting previously adopted IPM strategies. Sustainable tactics for implementing biological control strategies with exotic or native parasitoids are being investigated, seeking a long-term solution. This study aimed to assess the effects of different temperatures on the behavior of the two egg parasitoids, T. japonicus and T. mitsukurii that are native to Asia, but currently present in Europe. Therefore, this study intends to investigate the behavior of the two parasitoids during the overwintering period and immediately after by assessing the thermal requirements for mobility and probing towards the host species. The results showed that T. mitsukurii has been found to be active at lower temperatures than T. japonicus and thus in an early phase of the season. This can have implications in the competition between the two parasitoids, and in an earlier occupation of the ecological niches. However, T. japonicus exhibit higher performance in term of egg probing to H. halys, confirming its high potential as biocontrol agent.