Inves ga ons 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, par culary of fruits and seeds, Halyomorpha halys (Heteroptera, Pentatomidae)( Fig. 1), na ve H. halys can cause deformi es, suberifica on, discolora on, necro c 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 associa on with have increased the use of broad spectrum insec cides, resul ng in disrup on of the most manmade structures during the overwinter period, that Innova ve IPM strategies, with serious risks for both the economy and the environment. facilitates human assisted spread, this insect is a fast In par cular, the massive use of these insec cides can lead to the reduc on 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 iden fy 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 essen al oils in comparison with the a rac veness 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 Inser on point predator Prey items of the insects prey
Protocol eggs A er 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. A er 48 hours the survival Essen al oil concentra on 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 essen al 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) -ac ve 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) A er a 24h period of fas ng, the adults were inserted individually into the tube. A check was Pholidoptera li oralis (Orthoptera, Te gonidae) performed a er 1h, a er 6h and a er 24h, observing in which direc on 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 a rac ve trees for H. halys were selected. On each tree a tree-bea ng session (Fig. 3) X100 was performed using a s ck and a tray. N2 N3 In the four urban parks there was also a sweep net session (Fig.4) consis ng of 10 shots in 5 points characterized by Nest arena tall grass. The poten al 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. A er 24h In the next months the gut content of the aluminum sheet will be removed. A er 24h on the plant, an eggmass or 6 individuals for each the collected predators will be Fig.3 a tree-bea ng session Fig. 4 a sweep net session nymphal stage will be placed. A check will be performed a er 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 li oralis 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 li oralis is the only predator 20% 20% 20% capable of preda ng 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