Invesgaons on biology and behavior of Halyomorpha halys (Heteroptera: Pentatomidae) aimed at its sustainable management in agro-ecosystems PH.D student: Giacomo Bulgarini Tutor: Dr Lara Maistrello Doctorate in Agri-Food Science, Techologies and Bio-Technologies XXXIII cycle, 1° year Introduc&on Using its piercing-sucking apparatus on plants ssues, parBculary of fruits and seeds, Halyomorpha halys (Heteroptera, Pentatomidae)( Fig. 1), nave H. halys can cause deformies, suberificaon, discoloraon, necroc areas and watery rot, to East Asia, is a polyphagous species with more than 300 host that render products unmarketable (Fig. 2). To manage the invasion of this pest, farmers plants recognized. Thanks to its close associaon with have increased the use of broad spectrum insecBcides, resulBng in disrupBon of the most manmade structures during the overwinter period, that Innovave IPM strategies, with serious risks for both the economy and the environment. facilitates human assisted spread, this insect is a fast In parBcular, the massive use of these insecBcides can lead to the reducBon of beneficial spreading invasive pest of fruit orchards and many other crops insects, such as pollinators, parasitoids and predators, altering balance in agroecosystems. Therefore, it is necessary to idenBfy more sustainable strategies to manage this pest. both in the U.S.A., in Italy and other European countries Fig. 1 Adult of H. halys Fig. 2 examples of damage from H. halys Aim The project is focused on the sustainable management of the invasive alien species H. halys. Specifically, the work was divided into different trials: 1. Repellency test: The repellency of essenBal oils in comparison with the aracBveness of the food on starving individuals was tested. 2. Predatory test: The predatory ability of solitary generalist predators was tested on eggs and the first two instars of the H.halys. 3. Predatory sampling and gut content analysis: Predators were field-sampled in the Reggio Emilia urban parks and their gut content will be analysed. 4. Predatory test with social insects: The predatory ability of the ant species Lasius niger on the eggs and all the juvenile stages of H. halys will be test. Trial 1 Trial 2 Experimetal setup Experimental setup InserBon point predator Prey items of the insects prey Protocol eggs Aer a starving period of 24h, each predator was individually placed inside a A B transparent box with the H. halys prey item. For each N1 the ends of the tube were plugged replicate, a control was with filter paper soaked with carried out, with the same A=50 µl of ethanol (control) set up but without the B= mix of oil and ethanol (treatment) presence of the predator. Aer 48 hours the survival EssenBal oil concentraon tested: of the prey items and the N2 In each box 50%, 25%, 12%, 6%, 3%, 1% Each end of predators was recorded. the tube Four essenBal oils tested Predators tested: Adalia bipunctata (Coleoptera, Coccinellidae) adult H. halys individuals tested (5M and 5F) Anthocoris nemoralis (Rhyncota, Anthocoridae) -coming out from overwintering phase adults and larvae of Cryptolaemus montrouzieri (Coleoptera, Coccinellidae) -acBve during summer Chrysoperla carnea (Neuroptera, Chrysopidae) larvae -entering overwintering Forficula auricularia (Dermaptera, Forficulidae) Harmonia axyridis (Coleoptera, Coccinellidae) adult two species of the Himacerus genus (Rhyncota, Nabidae) Protocol Nagusta goedelii (Rhyncota, Reduviidae) AJer a 24h period of fasBng, the adults were inserted individually into the tube. A check was Pholidoptera lioralis (Orthoptera, Tegonidae) performed aer 1h, aer 6h and aer 24h, observing in which direcBon the individuals were directed. Rhynocoris iracundus (Rhyncota, Reduviidae) Trial 3 Trial 4 Preys Four urban parks of the city of Reggio Emilia were selected with an area of at least 500 square meters, Experimental setup close (30-50 m) to a water source and close to an agro-ecosystem. Protocol eggs N1 In these urban parks, 20 aracBve trees for H. halys were selected. On each tree a tree-beang session (Fig. 3) X100 was performed using a sBck and a tray. N2 N3 In the four urban parks there was also a sweep net session (Fig.4) consisBng of 10 shots in 5 points characterized by Nest arena tall grass. The potenBal predators were collected in falcon vials, then N4 N5 transferred in the freezer at -20°C. Sampling was performed in each park Protocol every 15 days from the beginning of At the beginning it will be allowed to ants to reach the plant. On the plant, a small sheet of aluminum May to the beginning of October. with drops of honey will be placed, so that the ants recognize the plant as a source of food. AJer 24h In the next months the gut content of the aluminum sheet will be removed. AJer 24h on the plant, an eggmass or 6 individuals for each the collected predators will be Fig.3 a tree-beang session Fig. 4 a sweep net session nymphal stage will be placed. A check will be performed aer 2h, 6h, 24h and 48h, recording the analysed using molecular techniques number of dead preys. For each replicate, a control will be carried out, with the same set up but to see if they had preyed on H. halys. without the presence of the ants. First results –Trial 2 From the comparison between Pholidoptera li7oralis Chrysoperla carnea larvae Nagusta goedelii 100% * * * * 100% * 100% * the survivors of the treatment 90% 90% 90% group (prey and predator) and 80% 80% 80% 70% 70% 70% the control one (no predators) 60% 60% 60% 50% 50% 50% predator predator predator it emerged that: Pholidoptera 40% 40% 40% Survival rate Survival rate 30% control 30% control Survival rate 30% control lioralis is the only predator 20% 20% 20% capable of predang all the 10% 10% 10% 0% 0% 0% instars tested, including eggs. eggs hatching N1 N2 eggs hatching N1 N2 eggs hatching N1 N2 N. goedelii, C. carnea larvae Development stages Development stages Development stages and nabids from Himacerus Nabids from Himacerus genus Rhynocoris iracundus genus significantly predated 100% * * 100% * * the first instars 90% 90% 80% 80% R. iracundus and nabids of the 70% 70% 60% 60% Himacerus genus significantly 50% 50% predator predator 40% 40% survival rate preyed on second instars. Survival rate 30% control 30% control R. iracundus significantly 20% 20% 10% 10% predated also adult individuals 0% 0% eggs hatching N1 N2 eggs hatching N1 N2 adults of H. halys. Development stages Development stages .