Marmorated Stink Bug Halyomorpha Halys Research Articles

Quantitative and qualitative damage caused by Halyomorpha halys (Hemiptera: Pentatomidae) on soybean crop at different growth stages

The brown marmorated stink bug Halyomorpha halys, an invasive species native to East Asia, is now present and abundant on soybean throughout Europe where it has become a major pest damaging the crop. Because a better understanding of the impact of H. halys is crucial to implement effective and sustainable pest management, the present study aimed to assess the stages at which soybean is most susceptible to H. halys attacks, and the qualitative and quantitative alterations caused by its feeding on soybean seeds. Therefore, soybean plants were exposed to stink bug adults for 2 weeks at different development stages and were examined at harvest for damage. Stay-green syndrome occurred most severely as a result of H. halys attacks at soybean development stages R4-R5. In the same period, the bug feeding activity significantly reduced the number of seeds per pod, thus indicating a higher damage rate at the R4-R5 stage when soybean surveillance should be intensified in order to properly target pest management strategies. The lower number of seeds per pod corresponded to an increase in the seed weight due to plant compensation mechanisms, leading to grain yields that did not differ in relation to the time of attack or the rate of damaged seeds. However, while not causing overall a loss of weight production, H. halys attacks were shown to cause qualitative damage to soybean seeds, especially by altering protein content and mobilizing several primary metabolites from storage macromolecules, which will have to be considered depending on the intended use of the production.

Parasitic behaviour and developmental morphology of Anastatus japonicus reared on the factitious host Antheraea pernyi.

The egg parasitoid Anastatus japonicus is a key natural enemy in the biological control of various agricultural and forestry pests. It is particularly used against the brown marmorated stink bug Halyomorpha halys and the emerging defoliator pest Caligula japonica in East Asia. It has been proved that the eggs of Antheraea pernyi can be used as a factitious host for the mass production of A. japonicus. This study systematically documented the parasitic behaviour and developmental morphology exhibited by A. japonicus on the eggs of A. pernyi. The parasitic behaviour of A. japonicus encompassed ten steps including searching, antennation, locating, digging, probing, detecting, oviposition, host-feeding, grooming, and resting. Oviposition, in particular, was observed to occur in three stages, with the parasitoids releasing eggs during the second stage when the body remained relatively static. Among all the steps of parasitic behaviour, probing accounted for the longest time, constituting 33.1% of the whole time. It was followed by digging (19.3%), oviposition (18.5%), antennation (9.6%), detecting (7.4%), and the remaining steps, each occupying less than 5.0% of the total event time. The pre-emergence of adult A. japonicus involves four stages: egg (0 to 2nd day), larva (3rd to 9th day), pre-pupa (10th to 13th day), pupa (14th to 22nd day), and subsequent development into an adult. Typically, it takes 25.60 ± 0.30 days to develop from an egg to an adult at 25℃. This information increases the understanding of the biology of A. japonicus and may provide a reference for optimising reproductive devices.

Comparative life tables of Trissolcus japonicus and Trissolcus mitsukurii, egg parasitoids of Halyomorpha halys

Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) and Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae) are Asian egg parasitoids that are considered important natural enemies of the brown marmorated stink bug Halyomorpha halys (Stål) (Hemiptera: Pentatomidae). These species are expanding their geographic distribution outside their native area, which suggests investigating their adaptability to environmental conditions. In a laboratory experiment, we investigated the life table parameters of these two egg parasitoid species under four constant temperatures, i.e., 16, 21, 26 and 31 °C. Results showed that the longevity of T. japonicus was higher than that of T. mitsukurii at all temperatures considered. The net reproductive rate (Ro) of T. japonicus was higher than that of T. mitsukurii at 26 and 31 °C. However, the intrinsic rate of increase (rm) at 26 and 31 °C was similar between the two species, and at 21 °C, T. mitsukurii exhibited a higher intrinsic and finite rate of increase. The two species complete their development at 16 °C, but with the lowest performances. Results suggest a higher increase of T. mitsukurii population when mean temperatures are equal to 21 °C, while the population increase of T. japonicus is expected to be favoured at higher temperatures.

The Potential of Distribution of the Brown Marmorated Stink Bug Halyomorpha halys (Heteroptera: Pentatomidae) in Europe Determined on the Basis of the Comparative Analysis of the Ecogeographical Borders of Its Range

The Potential of Distribution of the Brown Marmorated Stink Bug Halyomorpha halys (Heteroptera: Pentatomidae) in Europe Determined on the Basis of the Comparative Analysis of the Ecogeographical Borders of Its Range

Seasonal abundance and trap comparisons of the invasive brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae) adults from its native region

A challenging, yet fundamental part of initiating effective control measures against an invasive pest species is developing reliable means of monitoring the pest’s seasonal abundance. Halyomorpha halys, a polyphagous insect pest native to East Asia, has become a major economic threat to agricultural systems following unintentional introductions to North America, South America, and Europe. Research involving the seasonal phenology and monitoring attractant preferences of H. halys from its native range remain scarce. An 11-year collection of H. halys monitoring trap data from black light, incandescent light, and methyl (E, E, Z)-2, 4, 6-decatrienoate (MDT) lured traps from three locations in Kyoto, Japan was analyzed to fill gaps in knowledge relating to the native seasonal abundance and effectiveness of diferent trapping techniques for the pest. Due to a high amount of zero trap counts, a zero-inflated approach was taken to analyze the dataset. Overall, H. halys followed a bell-shaped population trend in Kyoto, with abundance peaking in the mid-summer. The attractant preference of H. halys varied slightly with the season, with black light traps producing to highest mean trap counts. The MDT lure traps generated the lowest mean trap counts, but displayed potential use in the reliable detection of early season H. halys. This work is expected to provide greater insight on H. halys in its native range and ultimately help refine existing management programs in invaded regions.

The post-diapause vibrational behavior, motility, and survival of the brown marmorated stink bug Halyomorpha halys (Stål) adults at different temperatures

Substrate-borne vibrational communication is common in pentatomids. Although several works exist on the vibrational communication of Halyomorpha halys, its vibrational behavior post diapause has not been investigated. In this study, we recorded H. halys overwintered adults using laser doppler vibrometers at three temperatures: 10 °C (inactivity), 18 °C (breaking of diapause), and 25 °C (peak of mating activity). The aim was to assess the effect of temperature on the signaling, motility, and survival of H. halys. The insects were sexed into different cages and recorded separately or joined with a cage of the opposite sex. We calculated the total time spent on signaling and walking per replica. The males predominantly emitted male signal 1 (MS1) throughout the four months of recordings. The females exclusively emitted female signal 2 (FS2) when joined with the opposite sex cage the first two months of recordings. Interestingly, they also started FS2 signaling when recorded separately, after two months. No signaling was recorded at 10 °C. At 25 °C, the signaling latency time before vibrational signaling was 24 h compared to 23 days at 18 °C. The short latency time at 25 °C correlated with a higher death rate in early stages of recording. Male walking activity was significantly higher in joined cages at 18 °C and 25 °C, suggesting the increased searching behavior near the opposite sex. Overwintered H. halys could adapt to different conditions whereas low temperatures maintain the diapause which is characterized by no signaling activity. Our results provide a foundation for bioclimatic modeling of climate change effects on H. halys and insights into the use of vibrational playbacks for mass trapping and monitoring as control techniques.

RESEARCH REGARDING THE PRESENCE OF BROWN MARMORATED STINK BUG Halyomorpha halys Stål IN DOLJ COUNTY

The brown marmorated stink bug Halyomorpha halys Stål (Hemiptera, Pentatomidae) is a new invasive species that appeared in RO in 2015 and was reported by us in two localities in Dolj county in 2023. H. halys, attacks over 100 plant species, in Dolj county we report its occurrence on horticultural plantse : apricot, grape vine, tomato and pepper.

Interactions between egg parasitoids and predatory ants for the biocontrol of the invasive brown marmorated stink bug Halyomorpha halys

AbstractThe brown marmorated stink bug Halyomorpha halys is an Asian species that has become a major agricultural pest in North America and Europe. Ants from the genus Crematogaster are predators of H. halys nymphs in Asia, as well as in the Mediterranean, where known native predators are still few. At the same time, ants usually do not harm H. halys eggs, which are the target of the main biological control agents, the scelionid parasitoids of the genus Trissolcus. However, ants, as generalist predators and territorial organisms, may kill or displace a variety of other insects, potentially interfering with parasitoids and biological control programmes. We conducted laboratory experiments to investigate the interactions between the Mediterranean ant Crematogaster scutellaris and the parasitoids T. japonicus and T. mitsukurii, evaluating the possibility that the ants could damage the parasitized eggs, attack the parasitoids during emergence or interfere with the egg‐laying behaviour of female parasitoids. Our results demonstrate that C. scutellaris is not able to damage parasitized eggs and is not aggressive towards adult parasitoids at any stage. The presence of ants can slow down the parasitization rate in T. mitsukurii females in the smallest laboratory setups; however, this has not been observed in a more natural setting. We suggest that ants may play a complementary role together with egg‐parasitoids in the control of H. halys without interfering with each other.

Distribution and prevalence of viral genomes in Italian populations of the invasive brown marmorated stink bug Halyomorpha halys

Halyomorpha halys (Stål), the brown marmorated stink bug, is a highly invasive insect species that causes significant agricultural losses, especially to orchard fruits, vegetables, herbaceous and ornamental plants. It is also a nuisance pest that seeks shelter in indoor spaces during the winter months. Harnessing the H. halys virome can result in new environmentally sustainable approaches to contain its populations and its relatated agricultural damages.In this study, RNA-Seq data were used to explore the virome associated to ten field populations collected in the Lombardy region in Northern Italy. We identified six complete viral genomes, three of which were previously unknown, belonging to the orders Reovirales, Articulavirales, Ghabrivirales, Durnavirales, and Picornavirales. The prevalence of the six viruses was evaluated by Real-time reverse transcription-quantitative PCR on eighty individuals. Halyomorpha halys ifla-like virus 2 turned out to be the most geographically widespread virus, as it was found in more than 50% of the analyzed insects and in nine out of the ten sampling locations. Moreover, in some individuals, this iflavirus was found in association with each of the other viruses in various combinations that involved up to four viruses. Further studies on such virus-virus interactions and their relationships with the insect host may open the possibility to exploit these naturally occurring viruses as specific and targeted biocontrol agents of H. halys.

Features and dynamics of species composition of entomoacarosystems in plum orchards

The long-term analysis of the entomocomplex of plum orchards, carried out in Krasnodar Territory, revealed variations in the quantitative composition of entomofauna of harmful species and the level of their harmfulness. It was established that, in the period from 2005 to 2021, the rotation of dominant and secondary species occurred. The main species included plum Grapholitha funebrana Treitschke and oriental Grapholitha molesta Busck fruit moths, plum black Haploca minuta Christ. and yellow Hoplocampa flava L. sawflies, plum aphid Hyalopterus pruni Geoffr. and twospotted spider mite Tetranychus urticae Koch. Associated species included plum gall Acalitus phloeocoptes (Nal.) and hawthorn Tetranuchus viennensis Zacher. mites, fruit-tree Tibicina haematodes Scopoli and citrus flatid Metcalfa pruinosa (Say) planthoppers and leaf roller moths of Tortricidae family. The group characterised by a limited distribution area includes the Californian Quadraspidiotus perniciosus Comst. and Turanian Diaspidiotus prunorum Laing. scales, plum Sphaerolecanium prunastri Fonsc and European brown Parthenolecanium corni Bouche. scales, seed wasps Eurytoma amygdali End., brown marmorated stinkbug Halyomorpha halys (Stål) and secondary insects (unequal bark beetle Xyleborus dispar F., fruit tree bark beetle Scolytus rugulosus (P.W.J. Müller), wood leopard moth Zeuzera pyrina L). When considering the structure formation of phytophage complex according to phylogenetic specialization, taking into account trophic relationships, it was established that the proportion of polyphages is 2.5 times higher than that of oligophages and 8.5 times higher than that of monophages from the total number of registered pest species. In the past decade, a reduction of pesticide load in plum agrocenoses has been observed due to the wider use of agrotechnical methods and the inclusion of bioregulatory and biological insecticides into protection systems, which contributed to the preservation and increase of beneficial fauna. Entomophages constitute 7–10% of the total number of entomoacrocenosis dominated by Hymenoptera and Coleoptera classes and mites of Acari subclass. The long-term monitoring of species composition, rotation of dominant and secondary pest species and entomophages, variations in their number and harmfulness, seasonal dynamics, trophic relationships of plum entomoacrocenosis under varying environmental conditions and increasing intensification of agricultural production expand the possibility of phytosanitary optimisation strategy of perennial agrocenoses in the south of Russia. This contributes to the preservation of regional biodiversity, as well as to the stable production of high-quality ecologically safe products with minimal negative impact on the environment.

Monitoring of the Brown marmorated stink bug Halyomorpha halys (Stål, 1855) in Banja Luka, Bosnia and Herzegovina

Brown marmorated stink bug Halyomorpha halys (Stål, 1855) is an invasive and polyphagous stink bug native to Asia. It has recently invaded Europe and Bosnia and Herzegovina. It is highly polyphagous pest of many economically important commodities including tree fruit, nut crops, field crops, vegetables and ornamentals. Moreover, it is an important nuisance pest because large numbers of adults seek out artificial structures for overwintering. Monitoring of population dynamics of H. halys during two years (2020 and 2021) was performed in Banja Luka, Bosnia and Herzegovina. The pest was present through monitoring period April–October with the highest abundance in the third decade of July when all life stages were present. More individuals were caught on pyramid trap (845) compared to sticky trap (156) favoring pyramid trap for future monitoring. Total number of caught individuals was 6.5 folds higher in the second year of the monitoring indicating population increase that presents threat to agricultural production.

The Invasive Caucasian Populations of the Brown Marmorated Stink Bug Halyomorpha halys (Hemiptera: Heteroptera: Pentatomidae) Rapidly Adapt Their Ecophysiological Traits to the Local Environmental Conditions

The ability to rapidly adapt to new environmental conditions is a crucial prerequisite for the wide-scale invasion of pests or intentional introduction of beneficial insects. A photoperiodically induced facultative winter diapause is an important adaptation ensuring synchronization of insect development and reproduction with the local seasonal dynamics of environmental factors. We conducted a laboratory study aimed to compare photoperiodic responses of two invasive Caucasian populations of the brown marmorated stink bug Halyomorpha halys (Hemiptera: Heteroptera: Pentatomidae), which recently invaded neighboring regions with subtropical (Sukhum, Abkhazia) and temperate (Abinsk, Russia) climates. Under the temperature of 25 °C and the near-critical photoperiods of L:D = 15:9 h and 15.5:8.5 h, the population from Abinsk showed a slower pre-adult development and a stronger tendency to enter winter adult (reproductive) diapause compared to the population from Sukhum. This finding agreed with the difference between the local dynamics of the autumnal temperature decrease. Similar adaptive interpopulation differences in the patterns of diapause-inducing responses are known in other insect species but our finding is distinguished by a very short adaptation time: H. halys was first recorded in Sukhum in 2015 and in Abinsk in 2018. Thus, the differences between the compared populations might have evolved over a relatively short span of several years.

Особенности мониторинга коричнево-мраморного клопа Halyomorpha halys (Stål) с помощью феромонных ловушек в условиях Северного Кавказа

The article presents the results of testing two different types of pheromone traps for catching a dangerous quarantine pest — the brown marmorated stink bug Halyomorpha halys in the North Caucasus conditions. The data showed that the use of a small (hanging) accumulative pyramid shaped trap in hazelnut planting allowed increasing the catches of adults of Halyomorpha halys by 94 % and nymphs by 75 %, in comparison with a large (ground) accumulative pyramid shaped trap. During the trial, the conditions under which the pests nymphs and adults were actively caught in pheromone traps were determined. The main catch of nymphs — 83 % was fixed at temperatures from +20 to +25 °C, while 52 % adults — at +25...+ 30 °C. The percentage of adults and nymphs of the brown marmorated stink bug caught in the traps was about the same level and amounted to 53 % and 47 %, respectively.

Headspace determination of the volatile organic compounds (VOCs) emitted by host plants of the brown marmorated stink bug Halyomorpha halys

The emission of volatile organic compounds (VOCs) from plants is associated with biotic and abiotic stress and depends on the plant species, organs, and developmental stage. Insects use VOCs to locate their host plants and their behavior is heavily influenced by the chemical profile of each at its current phenological stage. The brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae) is a highly polyphagous pest that causes significant damage to tree, vegetable, and ornamental crops worldwide. The volatile profiles of five hosts of H. halys were compared for common substances to provide insight into this insect’s extreme polyphagy. Headspace collection of volatile substances was performed for five hosts of H. halys by gas chromatography – mass spectrometry (GC-MS), and their VOC profiles were compared. The results show that, although the volatile profiles of the host plants differ substantially, 13 out of the 68 identified compounds were shared. These results suggest that host recognition by H. halys is likely driven by a combination of attractive and possibly repellent compounds that work synergistically which is the first step toward decoding this pest’s polyphagous nature.

No adverse effects of symbiotic control on the parasitism of Halyomorpha halys by egg parasitoids

The brown marmorated stink bug Halyomorpha halys is a polyphagous insect, which has a devastating impact on agricultural production in many countries. The alteration of symbiont vertical transmission, by removing symbionts from stink bug eggs (symbiotic control), has been recently introduced in control programmes against this insect. A major advantage of this strategy is the compatibility with natural enemies, since it allows an insecticide-free approach that is not harmful to other agroecosystem components. However, the effect of anti-symbiont products on parasitism by egg parasitoids is still unexplored. Here, we investigated the impact on parasitism by native (Anastatus bifasciatus, Ooencyrtus telenomicida and Trissolcus kozlovi) and exotic (Trissolcus japonicus and Trissolcus mitsukurii) parasitoids that attack H. halys eggs, after treatment with the micronutrient biocomplex Dentamet®, used for symbiotic control. The native wasp species were tested in no-choice bioassays, showing that treatment of the egg masses did not affect emergence percentages, but the non-reproductive effects were often reduced by the biocomplex. The exotic species T. japonicus and T. mitsukurii were used in no-choice and paired choice bioassays, showing an opposite influence of Dentamet® on emergence percentage and preference in the two species. No-choice tests indicated the highest successful parasitoid emergence on biocomplex-treated egg masses for T. japonicus, while no preference in the paired comparison with eggs treated with water or untreated. In contrast, T. mitsukurii displayed the lowest parasitism after Dentamet® treatment in no-choice tests, and preferred egg masses without Dentamet® in paired choice tests. We did not record any natural symbiont acquisition by the parasitoids emerged from H. halys egg masses, indicating that the wasp fitness is very unlikely to be altered by dysbiotic effects resulting from treatments. Therefore, our results support a further implementation of symbiotic control in different crops in combination with biological control, as sustainable options for H. halys integrated pest management.

Biological Parameters, Phenology and Temperature Requirements of Halyomorpha halys (Hemiptera: Pentatomidae) in the Sub-Mediterranean Climate of Western Slovenia.

Simple SummaryThe invasive brown marmorated stink bug Halyomorpha halys, native to East Asia, has become one of the most damaging agricultural pests worldwide. After being first detected in Europe (in Switzerland), it is now widely spread throughout the European continent and many countries in Eurasia. Since its first appearance in Slovenia in 2017, it has caused extensive damage to fruit and vegetable production. Investigating the biology and behavior in local environmental conditions is the first step towards effective pest control. Information on the number of generations per year is crucial for anticipating critical phases of pest development and for adapting control measures that target the pest’s vulnerable life stages. A 3-year study (2019–2021) on the biological parameters of H. halys was performed outdoors in Nova Gorica (western Slovenia), confirming that in the sub-Mediterranean climate this pest has two overlapping generations per year. The net reproductive rates observed over the period studied indicate growing populations. The highest population growth was recorded in 2019, when the net reproductive rate of increase (R0) reached 14.84 for the summer generation and 5.64 for the overwintering generation. These findings reflect the current situation in Slovenia, where the growing populations of H. halys has been causing considerable damage to agricultural crops since 2019.In the last decade, the invasive brown marmorated stink bug Halyomorpha halys, native to East Asia, has become one of the most serious pests for agricultural crops worldwide. First detected in Europe (in Switzerland), the insect is now widely found across the European continent and many Eurasian countries. Since its first appearance in Slovenia in 2017 it has caused considerable damage to fruit and vegetable production. Understanding the biology and behavior in the local environmental conditions is of key importance for an effective pest management. Knowledge of the voltinism of the species is crucial to anticipate critical phases of pest development and for adapting control measures that target the vulnerable life stages of the pest. A 3-year study (2019–2021) of H. halys biological parameters was performed outdoors in Nova Gorica (western Slovenia), confirming that in the sub-Mediterranean climate this pest has two overlapping generations per year. The net reproductive rates observed in the studied period indicate growing populations. The highest population growth was recorded in 2019, when the net reproductive rate of increase (R0) reached 14.84 for the summer generation and 5.64 for the overwintering generation. These findings match the current situation in Slovenia, where increasing populations of H. halys and severe crop damage have been observed since 2019.

BROWN MARMORATED STINK BUG <i>HALYOMORPHA HALYS</i> (STÅL, 1855) (HETEROPTERA: PENTATOMIDAE) PENETRATED INTO ARMENIA

Data on the first registrations of invasive insect species - marmorated stink bug Halyomorpha halys (Stål, 1855) in Central (Yerevan city) and Northern Armenia (Lori region) are presented. It is presumed that the species penetrated to the north of the country as a result of independent expansion from Georgia, and to its central part due to unintentional delivery with cargo or fruit and vegetable products. The role of citizen scientists in revealing of the species is shown.

Distribution of brown marmorated stink bug (Halyomorpha halys (Stål, 1855); Hemiptera: Pentatomidae) in the Northeast part of the Carpathian Lowland (West Ukraine)

Halyomorpha halys (Stål, 1855) spread rapidly during the last five years and became common and abundant in Central Europe, especially in the urban environment. In the Carpathian basin, the West Ukrainian Transcarpathia county was the last region where this species has not been found yet. The first specimens of this invasive pest were sampled in Velyka Dobron’ in 2018 and in 2019 it was found in another neighbouring village and cities of Chop, Berehove and Uzhhorod. The data provided here is the first for West Ukraine and the second for the country following the published record from Odessa (SE Ukraine). Although H. halys is still less abundant and occupied mainly urban habitats, it will certainly cause nuisance for peoples and damages for farmers in the near future.

Retrospective host-specificity testing shows Trissolcus basalis (Wollaston) and the native Trissolcus oenone (Dodd) (Hymenoptera: Scelionidae) have overlapping physiological host ranges in New Zealand

Retrospective host range testing is essential for understanding the physiological host range of introduced biological control agents (BCAs) and updating forecasts of non-target risks. It is especially important to conduct this work if there was no host range testing prior to release of the agent. Trissolcus basalis Wollaston was released in New Zealand in 1949 against green vegetable bug (Nezara viridula [L.]), but host range testing was never undertaken, and subsequent work in the 1960s was only of a qualitative nature and remains incomplete. The host-parasitoid complex between New Zealand pentatomids, T. basalis, and the native pentatomid parasitoid Trissolcus oenone Dodd, is therefore poorly understood. We conducted no-choice oviposition tests between the two resident Trissolcus species and all available New Zealand pentatomid species to characterise the physiological (=fundamental) host ranges of these parasitoids. We present the results of the first retrospective host-specificity study on T. basalis in New Zealand. Our results show T. basalis attacks and develops in all nine pentatomid taxa we exposed it to (including the endemic alpine species Hypsithocus hudsonae Bergroth), while T. oenone attacks and develops in seven out of eight pentatomid species we tested it against (and its capacity to attack H. hudsonae remains unknown). Parasitism efficiencies for all treatments exceeded 60%, while development times were similar for both parasitoids regardless of host. We discuss the importance of physiological host range testing for understanding potential non-target effects. Trissolcus japonicus Ashmead (Hymenoptera: Scelionidae) was recently approved for release in New Zealand against brown marmorated stink bug Halyomorpha halys Stål (Hemiptera: Pentatomidae), subject to its potential establishment, and we examine our results in the context of potential competition between introduced parasitoids for non-target species.

Expressional and functional comparisons of five clustered odorant binding proteins in the brown marmorated stink bug Halyomorpha halys

Odorant-binding proteins (OBPs) play essential roles in the functioning of insect peripheral olfactory systems. To fully understand the olfactory roles of OBPs in Halyomorpha halys, an important invasive pest found worldwide, we studied the expression and functional characterization of five OBP-associated genes from H. halys that are clustered in the genome. The tissue distribution of the OBP gene cluster suggests that these genes were enriched in nymph and adult antennae, indicating their possible involvement in the chemosensory process. The different expression levels of the five OBPs in nymph and adult antennae suggest that this gene cluster is regulated independently. Ligand-binding experiments have shown similar specificities of these five OBPs towards several organic compounds, including the alarm pheromone of H. halys (trans-2-decenal), the aggregation pheromone of Plautia stali (methyl (2E, 4E, 6Z)-decatrienoate), and plant volatile compounds (e.g., cis-3-hexenyl benzoate and β-ionone). In particular, trans-2-dodecenal, an alarm pheromone analog, exhibited high affinity to the five OBP proteins and alarm pheromone activity towards H. halys. Thus, this OBP cluster may mediate the response of stink bugs to the both the alarm pheromone and host-related volatiles and could be an interesting target to design novel olfactory regulators for the management of H. halys infestations.