Assessing the Distribution of Exotic Egg Parasitoids of Halyomorpha halys in Europe with a Large-Scale Monitoring Program

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.

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The Influence of Marking Methods on Mobility, Survivorship, and Field Recovery of Halyomorpha halys (Hemiptera: Pentatomidae) Adults and Nymphs

Environmental Entomology ◽

10.1093/ee/nvaa095 ◽

2020 ◽

Vol 49 (5) ◽

pp. 1026-1031

Author(s):

Danielle M Kirkpatrick ◽

Kevin B Rice ◽

Aya Ibrahim ◽

Shelby J Fleischer ◽

John F Tooker ◽

...

Keyword(s):

Large Scale ◽

The United States ◽

Halyomorpha Halys ◽

Stink Bug ◽

Row Crops ◽

Fluorescent Powder ◽

Mark Release Recapture ◽

Economic Injury ◽

Polyphagous Insect ◽

Laboratory Bioassays

Abstract Halyomorpha halys (Stål), the brown marmorated stink bug, is an invasive and highly polyphagous insect that has caused serious economic injury to specialty and row crops in the United States and Europe. Here, we evaluated the effects of marking adult and nymphal H. halys with four different colors of fluorescent powder (Blaze Orange, Corona Pink, Horizon Blue, and Signal Green) on mobility and survivorship in laboratory bioassays. Adults and nymphs were marked using liquified fluorescent powder solutions and allowed to dry prior to bioassay. The presence of the marking solution had no significant effects on adult or nymphal mobility, adult survivorship, nymphal development, or adult flight capacity. We also evaluated the persistence of neon marker applied to the pronotum of H. halys adults and found this technique remained detectable for 2 wk under field conditions. Although both marking techniques are inexpensive, persist for ≥1 wk, and do not affect mortality, the neon marker method is more time-consuming, taking ~12 times longer to mark 50 adult H. halys compared with the liquified fluorescent powders. Thus, we would recommend using fluorescent powders for large-scale mark-release-recapture studies.

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Physiological Host Range of Trissolcus Mitsukurii, A Candidate Biological Control Agent of Halyomorpha Halys

10.21203/rs.3.rs-362649/v1 ◽

2021 ◽

Author(s):

Lucrezia Giovannini ◽

Giuseppino Sabbatini-Peverieri ◽

Leonardo Marianelli ◽

Gabriele Rondoni ◽

Eric Conti ◽

...

Keyword(s):

Biological Control ◽

Host Range ◽

Biocontrol Agent ◽

Biological Control Agent ◽

Classical Biological Control ◽

Egg Parasitoid ◽

Control Agent ◽

Egg Load ◽

Halyomorpha Halys ◽

Stink Bug

Abstract The invasive stink bug Halyomorpha halys is a severe agricultural pest of worldwide importance, and chemical insecticides are largely sprayed for the control of its populations. Negative impacts and several failures in chemical pest management led to consider classical biological control as one of the most promising methods in a long-term perspective. The Asian egg parasitoid Trissolcus japonicus is the main candidate biocontrol agent of H. halys, but more recently a second Asian egg parasitoid, Trissolcus mitsukurii, is getting attention after adventive populations were found on H. halys egg masses in Europe. Before recommending the use of T. mitsukurii for biological control of H. halys, a risk analysis is necessary and therefore here we present the first study on the fundamental physiological host range of this parasitoid in Europe. Tests conducted with T. mitsukurii on different hemipterans, using three different experimental designs, revealed a broad physiological host range, comparable with the host range displayed by T. japonicus under similar laboratory conditions. Specifically, in addition to its coevolved host H. halys, T. mitsukurii successfully parasitized the majority of tested pentatomid species and one scutellerid, although with highly variable emergence rates. Host egg sizes positively affected parasitoid size and female egg load. Further studies, testing more complex systems that involve olfactory cues from host and host plants, will simulate different aspects of the parasitoid host location behavior under field conditions, allowing in-depth evaluation of the possible risks associated with the use of T. mitsukurii as a biocontrol agent of H. halys.

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Host Kairomones Influence Searching Behavior of Trissolcus japonicus (Hymenoptera: Scelionidae), a Parasitoid of Halyomorpha halys (Heteroptera: Pentatomidae)

Environmental Entomology ◽

10.1093/ee/nvz155 ◽

2019 ◽

Vol 49 (1) ◽

pp. 15-20 ◽

Cited By ~ 5

Author(s):

Sean M Boyle ◽

Donald C Weber ◽

Judith Hough-Goldstein ◽

Kim A Hoelmer

Keyword(s):

Host Range ◽

Classical Biological Control ◽

Egg Parasitoid ◽

Halyomorpha Halys ◽

Stink Bug ◽

Red Maple ◽

Classical Biocontrol ◽

Trissolcus Japonicus ◽

Walking Velocity ◽

Heteroptera Pentatomidae

Abstract The brown marmorated stink bug, Halyomorpha halys (Stål), is a highly polyphagous species native to Asia that has become a serious invasive agricultural and nuisance pest across North America and Europe. Classical biological control host range evaluations have revealed egg parasitoid Trissolcus japonicus (Ashmead) to be the primary candidate biocontrol agent for field release against H. halys. However, these evaluations only provide us with the physiological host range of T. japonicus. Other Trissolcus species have demonstrated that contact kairomones from different host species elicit varied responses in the parasitoids’ host foraging behaviors. To assess T. japonicus response to host kairomones, mated naive females were exposed to leaf surfaces contaminated with adult kairomones from its preferred host, H. halys, or from a native nontarget host, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Red maple, apple, and soybean were used as plant substrate treatments. The wasp’s residence time on the leaf surface, linear walking velocity, and angular walking velocity were observed and measured using Noldus EthoVision XT tracking software. Within each leaf treatment, T. japonicus displayed stronger behavioral responses on leaves contaminated with contact kairomones from H. halys. The parasitoid resided on H. halys contaminated leaves for approximately twice as a long as it did on P. maculiventris contaminated leaves. Further, both species’ kairomones elicited significant decreases in parasitoid walking velocity on all tested substrate types. Overall, our study suggests that kairomone-based behavioral studies can be used to further evaluate the host specificity of T. japonicus and can be an invaluable supplement to classical biocontrol host range testing regimes.

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Occurrence and Molecular Variability of Kiwifruit Viruses in Actinidia deliciosa ‘Xuxiang’ in the Shaanxi Province of China

Plant Disease ◽

10.1094/pdis-09-18-1570-re ◽

2019 ◽

Vol 103 (6) ◽

pp. 1309-1318 ◽

Cited By ~ 4

Author(s):

Lei Zhao ◽

Wen Yang ◽

Yuanle Zhang ◽

Zhanmin Wu ◽

Qiao-Chun Wang ◽

...

Keyword(s):

Large Scale ◽

Primary Source ◽

Potato Virus X ◽

Shaanxi Province ◽

Multiple Infection ◽

First Report ◽

Molecular Variability ◽

Large Scale Survey ◽

Actinidia Spp ◽

Main Producer

Kiwifruit (Actinidia spp.) is an economically substantial fruit crop with China the main producer. China is the primary source of wild kiwifruit and the largest producer of kiwifruit in terms of both production and planting area, and Shaanxi province is the largest kiwifruit producer in China. Previous studies reported presence of kiwifruit viruses in Actinidia chinensis. In this study, six viruses were identified in kiwifruit ‘Xuxiang’ (A. deliciosa) in Shaanxi, China. The incidence, distribution, and genetic diversity of these viruses were studied. The results showed that Actinidia virus A (AcVA), Actinidia virus B (AcVB), Actinidia chlorotic ringspot-associated virus (AcCRaV), cucumber mosaic virus (CMV), apple stem grooving virus (ASGV), and potato virus X (PVX) were the main viruses infecting Xuxiang kiwifruit in Shaanxi, China. Incidence of the various viruses with both single and multiple infection varied with different kiwifruit-growing counties. For single virus infection, the highest and the lowest numbers of samples infected were about 22 for AcCRaV and 0 for AcVB in Meixian out of 170 samples, 12 for AcVA and 0 for CMV in Zhouzhi out of 120 samples, 10 for AcVA and 0 for AcVB, AcCRaV, ASGV, PVX, and CMV in Yangling out of 70 samples, and 8 for AcCRaV and CMV and 0 for AcVA, AcVB, ASGV, and PVX in Hanzhong out of 80 samples, respectively. Samples which were multiply infected with two or more viruses were also detected. Analysis of the phylogenetic tree of these viruses showed some genetic variability in the AcVA, AcVB, and AcCRaV isolates of Shaanxi kiwifruit. There was no obvious molecular variation in the coat protein genes of ASGV, CMV, and PVX virus isolates from Shaanxi kiwifruit. The present study is the first large-scale survey of kiwifruit viruses in Shaanxi, China. To our knowledge, this is the first report of PVX infecting kiwifruit and the first report of molecular variability of AcVA, AcVB, and AcCRaV. These results provide important data for studying the genetic evolution of AcVA, AcVB, AcCRaV, ASGV, CMV, and PVX.

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Correcting Citizens’ Misperceptions about non-Western Immigrants: Corrective Information, Interpretations, and Policy Opinions

Journal of Experimental Political Science ◽

10.1017/xps.2020.35 ◽

2020 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Frederik Juhl Jørgensen ◽

Mathias Osmundsen

Keyword(s):

Immigration Policy ◽

Large Scale ◽

Total Population ◽

Survey Experiment ◽

Correct Information ◽

The Usa ◽

Large Scale Survey ◽

Nationally Representative ◽

Information Change ◽

Corrective Information

Abstract Can corrective information change citizens’ misperceptions about immigrants and subsequently lead to favorable immigration opinions? While prior studies from the USA document how corrections about the size of minority populations fail to change citizens’ immigration-related opinions, they do not examine how other facts that speak to immigrants’ cultural or economic dependency rates can influence immigration policy opinions. To extend earlier work, we conducted a large-scale survey experiment fielded to a nationally representative sample of Danes. We randomly expose participants to information about non-Western immigrants’ (1) welfare dependency rate, (2) crime rate, and (3) proportion of the total population. We find that participants update their factual beliefs in light of correct information, but reinterpret the information in a highly selective fashion, ultimately failing to change their policy preferences.

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