Refining Pheromone Lures for the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) Through Collaborative Trials in the United States and Europe.

Brown marmorated stink bug, Halyomorpha halys, is native to Asia and has invaded North America and Europe inflicting serious agricultural damage to specialty and row crops. Tools to monitor the spread of H. halys include traps baited with the two-component aggregation pheromone (PHER), (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol, and pheromone synergist, methyl (2E,4E,6Z)-decatrienoate (MDT). Here, an international team of researchers conducted trials aimed at evaluating prototype commercial lures for H. halys to establish relative attractiveness of: 1) low and high loading rates of PHER and MDT for monitoring tools and attract and kill tactics; 2) polyethylene lure delivery substrates; and 3) the inclusion of ethyl (2E,4E,6Z)-decatrieonate (EDT), a compound that enhances captures when combined with PHER in lures. In general, PHER loading rate had a greater impact on overall trap captures compared with loading of MDT, but reductions in PHER loading and accompanying lower trap captures could be offset by increasing loading of MDT. As MDT is less expensive to produce, these findings enable reduced production costs. Traps baited with lures containing PHER and EDT resulted in numerically increased captures when EDT was loaded at a high rate, but captures were not significantly greater than those traps baited with lures containing standard PHER and MDT. Experimental polyethylene vial dispensers did not outperform standard lure dispensers; trap captures were significantly lower in most cases. Ultimately, these results will enable refinement of commercially available lures for H. halys to balance attraction and sensitivity with production cost.

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.

Integrated management of Thrips tabaci (Thysanoptera: Thripidae) on onion in north-western Italy: basic approaches for supervised control.

BACKGROUND: Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a major pest on onion, Allium cepa L., worldwide. In 2010, research was conducted in a commercial onion field in north-western Italy in order (i) to evaluate the efficacy of different insecticides and of the SAR activator acibenzolar-S-methyl, (ii) to correlate thrips infestation levels with bulb size and weight at harvest and (iii) to implement a reliable thrips sampling method. Efficacy of the three active ingredients spinosad, lambda-cyhalothrin and acibenzolar-S-methyl on local thrips populations were also evaluated in laboratory bioassays. RESULTS: During field surveys, the highest and the lowest thrips infestations were observed in plots treated with lambda-cyhalothrin and with spinosad and acibenzolar-S-methyl respectively. The effectiveness of spinosad was also confirmed in laboratory bioassays. At harvest, bulb size and weight did not significantly differ between treatments. A high correlation with visual inspection made plant beating a suitable sampling method for routine practice, enabling a good estimate of thrips infestation. CONCLUSION: Damage caused by thrips is often not severe enough to warrant the frequent pesticide applications the crops receive in north-western Italy. The use of spinosad and acibenzolar-S-methyl is suggested as an alternative to conventional insecticides for the preservation of natural enemies.