ABSTRACT
The brown marmorated stink bug Halyomorpha halys is an invasive agricultural pest with a worldwide distribution. Classical biological control has been identified as the most promising method to reduce the populations of H. halys. Adventive populations of two candidates for releases, Trissolcus japonicus and Trissolcus mitsukurii, have recently been detected in Europe. To assess their distribution and abundance, a large-scale survey was performed. From May to September 2019, a wide area covering northern Italy and parts of Switzerland was surveyed, highlighting the expanding distribution of both Tr. japonicus and Tr. mitsukurii. Within four years after their first detection in Europe, both species have rapidly spread into all types of habitats where H. halys is present, showing a wide distribution and continuous expansion. Both exotic Trissolcus showed high levels of parasitism rate towards H. halys, while parasitization of non-target species was a rare event. The generalist Anastatus bifasciatus was the predominant native parasitoid of H. halys, while the emergence of native scelionids from H. halys eggs was rarely observed. The presence of the hyperparasitoid Acroclisoides sinicus was also recorded. This study provided fundamental data that supported the development of the first inoculative release program of Tr. japonicus in Europe.
ABSTRACT
Aim of the study was to investigate the performance of the new insecticide "spirotetramat" as an alternative solution of "abamectin" for the control of Cacopsylla pyri L. (Hemiptera: Psyllidae) in the context of an IPM program in European pear, Pyrus communis L.. Laboratory bioassays for the estimation of LC50 and LC90 of both insecticides were performed using four populations collected in Emilia-Romagna (Italy) orchards where different pest management strategies were used (organic, integrated, and conventional). The same populations were also analyzed for the main insecticide detoxifying activities in nymphs by spectrofluorimetric in vitro assays. The performance of the two insecticides was also tested on field on one population under integrated pest management conditions. The laboratory experiments showed that the LC90 of spirotetramat were lower than the highest field concentration allowed in Europe (172.80 mg AI liter(-1)) giving reassurance about the efficacy of the product. Concerning the abamectin, the laboratory bioassays did not show strong indications of resistance development of C. pyri populations of Emilia-Romagna. A similarity in enzyme detoxifying activity was observed in both insecticides indicating a general absence of a significant insecticide resistance. The field trial showed a high efficacy (>90 %) of spirotetramat on C. pyri already after 15 d from application, and it was significantly higher from abamectin. Overall, spirotetramat is one more choice for C. pyri control, as well as abamectin in order to minimize the risks of occurrence of insecticide resistance.
