First insights on early host plants and dispersal behavior of Halyomorpha halys (Hemiptera: Pentatomidae) from overwintering to crop colonization

Following its first detection in North Italy in 2012, H. halys has become a serious threat in many crops, including hazelnut. The present study aimed at investigating dispersal capacity and behavior in relation to host plants of overwintered adults of H. halys before the colonization of hazelnut crop. Research was carried out in four polyculture areas (from 14 to 50 ha) in north-western Italy in 2018, by using (i) pheromone-baited traps, (ii) visual inspection and beating sheet sampling, and (iii) immunomarking-capture technique. The relative abundance of H. halys was similar between and within the study areas, and the early attractiveness of lures to adults after overwintering was confirmed; the host plants near a pheromone trap (less than 5 m) hosted higher numbers of H. halys than the same plant species far away. Hybrid plane, European spindletree, walnut, oak, and European elder were the first plants on which adult bugs were observed to feed. By immunomarking-capture technique, H. halys showed both short- and long-range dispersal from overwintering sites and/or early host plants to wild and crop plants. Marked adults were found in all zones of each area, irrespective of the distance from the protein treatment. Therefore, H. halys movement patterns depend on the ecosystem features, and plant host distribution and availability. This knowledge together with the interaction between pheromone and early host plants might contribute to the management of post-overwintering adults

A survey of native parasitoids ofHalyomorpha halysin Northern Italy and Switzerland

Introduction: The brown marmorated stink bug, Halyomorpha halys,is an Asian polyphagous species that has become an invasive crop pest in North America and Europe. After its first detection in Switzerland in 2004, it was subsequently found in other European countries such as Italy, where, since 2012, it has rapidly spread in the northern regions, becoming a threat to many crops, especially in pear and peach orchards. Results/Conclusion: Overall, most egg parasitism was due to the generalist parasitoid Anastatus sp. (Eupelmidae) and, at a lower level, to various Scelionidae species (e.g. Trissolcus cultratus). In northern Italy, the amount of parasitized eggs ranged from 3.1% in 2014 to 0.9% in 2015 in Emilia Romagna, and from 0.3% on exposed egg-masses to 21.4% on egg-masses collected in a natural habitat in 2015 in Piedmont. Overall parasitism in Switzerland was 4.4% in 2013

Development and thermal activity thresholds of European mirid predatory bugs

Generalist predators belonging to Dicyphini (Hemiptera: Miridae) play an important role in pest control in vegetable crops. Temperature is one the most important factors affecting their efficacy as biological control agents (BCAs) and a better understanding of temperature effects can help to select the best performing species for certain climatic conditions. In this study we assessed the thermal requirements of six dicyphine species: Dicyphus bolivari (2 different strains), Dicyphus eckerleini, Dicyphus errans, Dicyphus flavoviridis, Nesidiocoris tenuis and Macrolophus pygmaeus. Two experimental methods were used: one static, by recording the developmental times at six temperatures (15–40 °C) and one dynamic, by determining low and high temperature thresholds for movement. Based on the results of both methods we identified two groups: N. tenuis, M. pygmaeus and D. bolivari showed the best performance at high temperatures and the species D. errans, D. eckerleini and D. flavoviridis were most active at low temperatures. Dicyphus bolivari and N. tenuis were the only species able to reach adulthood at the constant temperature of 35 °C. At low temperatures, D. eckerleini and D. errans were the only species still able to walk below 0 °C. The species less vulnerable for lower temperatures were more vulnerable for higher temperatures and vice-versa. Among the tested species, the larger sized species seem to be better adapted to lower temperature and the and smaller sized species better to higher temperatures. Females and males in all species differed in their cold and heat tolerance. Males were in general beter adapted to higher temperatures and females beter adapted to lower temperatures.</p