Pentatomidae Research Articles

Spatial variation in cocoa insect pest populations and its implication for pest management

ABSTRACT Currently, mirids, stink bugs and coreid bugs are the most important insect pests of cocoa in Ghana. The populations of these insect pests are known to be influenced by the availability of food and breeding sites, as well as the macro and micro climates in cocoa farms. The study investigated variations in the population dynamics of these pests and their damage trends within a square mile (259 hectares). Pest numbers and damage were assessed monthly on 100 trees per plot from 2015 to 2020, each plot measuring one acre (0.4 hectare). Significant differences (p < 0.05) were observed in pest numbers and damage symptoms of the different pest species for the various months of assessment. Populations of each pest species (mirids, stink bugs and the coreid bugs) and their associated damage in the various cocoa plots were significantly different (p < 0.05). The study showed that relying on the pest activity in one cocoa plantation to determine pest management activities in a nearby cocoa plot may not always lead to accurate and effective pest control. The need for pest surveillance and monitoring at the farm level as a basis to design effective Integrated Pest Management in cocoa production is discussed.

Native Australian Bronze Orange Stink Bug (Musgraveia sulciventris)–Related Corneal Injury

Abstract: The bronze orange stink bug (Musgraveia sulciventris) is an insect native to Australia that is found in citrus trees and gardens in coastal Queensland and New South Wales. The common name “stink bug” is attributed to the foul spray emitted from these insects when they are threatened. This spray can result in corneal injuries; however, human case reports of stink bug bodily fluid exposure to the eye are rare and have not been previously reported for this species. This report describes a case of the native Australian insect bronze orange stink bug causing irritant contact keratitis in the eye, which is the only reported case in the literature. Patients who garden in Queensland and New South Wales should be advised to handle these insects with care, by wearing protective eyewear and gloves when handling citrus trees or when removing them from their gardens, to minimize their risk of corneal damage if sprayed.

Silicon applications in rice plants alter the stylet probing behaviors of Glyphepomis spinosa (Hemiptera: Pentatomidae).

The stink bug Glyphepomis spinosa Campos & Grazia (Hemiptera: Pentatomidae) is a potential rice pest in Brazil. This study evaluates the interaction between silicon sources and 3 rice cultivars (BRS Esmeralda, Canela de Ferro, and IRGA 417) and examines how increasing silicon levels affect the stylet probing behavior of G. spinosa. The experiment was set up in a completely randomized design with a 3 × 3 factorial scheme (silicon sources: calcium silicate, potassium silicate, a control, and 3 rice cultivars). Fertilizing rice plants with Si altered the probing behavior of the stink bug G. spinosa. The cultivar interaction by Si source was significant in a few variables. This was evidenced by longer periods without ingestion, prolonged time to the first stylet probe (initial probing), and less time spent in cellular maceration. This result supports the use of electropenetrography as a tool to evaluate resistance inducers in plants.

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

Bioactivities of scent gland chemicals from Mictis fuscipes Hsiao (Hemiptera: Coreidae) on Solenopsis invicta Buren (Hymenoptera: Formicidae).

Given the chemical diversity within stink bugs scent glands, they can be convenient models for bioprospecting novel pest control products. Preliminary behaviour observations indicated that adult Mictis fuscipes stink bugs secrete liquid droplets when defending against Solenopsis invicta fire ants, killing them within minutes. Hence, this study aimed to analyse the chemical composition of the metathoracic scent gland secretions of M. fuscipes adults, as well as assess their biological activities against fire ants. Bioassaying fire ants against secretions of several local stink bugs confirmed that the defensive secretions of two Mictis species are significantly more lethal, where M. fuscipes was the most lethal. Volatiles chromatography analysis indicated the secretions of female and male M. fuscipes stink bugs contains 20 and 26 components, respectively, chiefly hexanoic acid and hexyl hexanoate. Five compounds were consistently present in the secretion of female adults: hexyl hexanoate, hexanoic acid, hexyl acetate, hexyl butyrate, and eugenol. These yielded a strong electrophysiological antennal (EAD) response from S. invicta workers, female alates and males, where hexyl acetate showed the strongest response. The combination of these five compounds proved strongly repellent to S. invicta. When tested singly, hexanoic acid, hexyl butyrate, hexyl hexanoate, and eugenol were repellent to S. invicta, but hexyl acetate seemed slightly attractive. Additionally, the same mixture of five components exhibited strong contact and fumigant toxicity towards S. invicta workers, eugenol being the strongest. Defensive chemicals of M. fuscipes exhibit robust biological activity against S. invicta and could inspire the development of biopesticides. © 2024 Society of Chemical Industry.

A lightweight and enhanced model for detecting the Neotropical brown stink bug, Euschistus heros (Hemiptera: Pentatomidae) based on YOLOv8 for soybean fields

Insect pest detection and monitoring are vital in an agricultural crop to help prevent losses and be more precise and sustainable regarding the consequent actions to be taken. Deep learning (DL) approaches have attracted attention, showing triumphant performance in many image-based applications. In the adult stage, this research considers detecting a vital insect pest in soybean crops, the Neotropical brown stink bug (Euschistus heros), from field images acquired by drones and cellphones. We develop and test an improved YOLO-model convolutional neural network (CNN) with fewer parameters than other state-of-the-art models and demonstrate its superior generalization and average precision on public image datasets and the new field data provided here. Considering the proposal's precision and time of response, the possibility of deploying this technology for automatic monitoring and pest management in the near future is promising. We provide open code and data for all the experiments performed.

Trapping strategy and diel periodicity affect capture rate of Halyomorpha halys (Hemiptera: Pentatomidae) in agroecosystems.

The polyphagous pest, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), damages fruit in orchards and field crops and is often found within nearby woodlands. Pheromone-baited traps can be used to monitor H. halys. However, the efficiency of trapping H. halys may vary depending on trapping strategy (live vs. dead capture), location (ground or canopy), and diel periodicity of captures. We compared H. halys capture within fruiting hosts for: (i) live and kill traps on the ground vs. traps in the canopy of black cherry (Prunus serotina Ehrh.) (Rosales: Rosaceae), sugarberry (Celtis laevigata Willdenow) (Rosales: Cannabaceae), and pecan (Carya illinoinensis (Wangenh.) K. Koch) (Fagales: Juglandaceae) trees, (ii) ground and canopy-live traps in sassafras (Sassafras albidum (Nutt.) Nees) (Laurales: Lauraceae), and (iii) whether diel periodicity was detected for live capture in sassafras and cotton. More H. halys adults and nymphs were captured in kill traps than in live traps. More nymphs were captured in kill traps in black cherry and sugarberry on the ground than in the canopy. Live adult capture was significantly greater in sassafras and pecan canopies than on the ground. In cotton and sassafras, more live adults were captured from 8 PM-noon, with the fewest captured from noon-6 PM. A better understanding of stink bug activity in the field allows for improved trapping and, possibly, improved timing of treatment applications.

Generative exhaustions: Thresholds of long-term uncertainty and stink bug infestation in Georgia’s contested borderland

ABSTRACT Displaced Georgians from the Gali region of the de facto Georgia–Abkhazia borderland have constructed mobile lives by navigating a decades-long conflict and its turbulent landscapes. For the people of Gali, cross-border mobility is a vital concern; uncertainty is a daily matter of tactical anticipation. Arbitrary checkpoints, unannounced border closures, and the Enguri River’s capricious water levels interfere with mobilities; occasional crises unsettle the subtle ways that the Gali people have developed over three decades to manoeuvre everyday uncertainties. Focusing on an unanticipated stink bug infestation that disrupted already precarious lives, this article explores the temporal and affective anatomy of long-term uncertainty with its continuities and limit points. Using exhaustion as an analytical concept, it examines the generative thresholds of protracted uncertainty without eclipsing the cumulative toll of continuous life struggle in a conflict zone.

The Effects of Temperature on the Development and Survival of Bathycoelia distincta (Hemiptera: Pentatomidae), a Significant Pest of Macadamia in South Africa.

Temperature is the most influential condition affecting insect development and population dynamics. Understanding its impact and other important factors, such as diet, could provide fine-scale predictions of species abundance and distribution in space and time. The two-spotted stink bug, Bathycoelia distincta Distant (Hemiptera: Pentatomidae), is a significant pest of macadamia in South Africa for which limited information on developmental biology exists. Here, for the first time, variations in key developmental parameters of the B. distincta biology were studied systematically. The developmental duration, survival rate, development rate, lower developmental threshold (Tmin), optimum developmental threshold (Topt), upper developmental threshold (Tmax), and thermal constant were quantified for each developmental stage of B. distincta. In addition, the effect of diet (macadamia nut and sweetcorn) on the developmental duration and survival rate were quantified. This study was conducted at five constant temperatures (18, 21, 22, 25, and 29 °C) with relative humidity (RH) variations. The developmental duration from egg to adult decreased significantly with increased temperature: 21 °C (±60 days) to 29 °C (±32 days). The survival rate was significantly different for instar 2 between temperatures. Nymphs (instars 2 and 4) developed faster on the sweetcorn diet than on a macadamia diet, but the total developmental time did not differ significantly between the diets. Development from egg to adult required 783 degree days (DD), with a Tmin of 13.5 °C, Topt of 29.5 °C, and Tmax of 38 °C. Ongoing global warming will increase the population growth of B. distincta through increased development rate, resulting in more damage to macadamia nuts. Understanding the developmental biology and thresholds for the DD model of B. distincta is fundamental for predicting its phenology and outbreaks in macadamia orchards.

Chemical and visual stimuli for conservation biological control of stink bugs in soybean: potential use and flaws on egg parasitoid recruitment

Chemical and visual stimuli for conservation biological control of stink bugs in soybean: potential use and flaws on egg parasitoid recruitment

Overwintering site selection and associated microclimates for the redbanded stink bug (Hemiptera: Pentatomidae), a non-native pest of soybean.

Cold winter temperatures govern the distribution and abundance of many insect species, but refugia that provide microclimates can moderate temperature-driven mortality. Winter temperatures have been implicated in limiting the survival and range of Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae; redbanded stink bug), an economically damaging invasive pest in the southeastern United States, but the role of refugia in overwintering survival of this pest is poorly understood. We conducted 2 studies in successive years to evaluate how leaf litter from hardwoods, pines, and soybeans modulate overwintering site selection and survival of P. guildinii. In the second-year study, we also quantified the buffering effect of the 3 leaf litter types compared to ambient conditions and assessed diapause. In the first-year study, we found that stink bugs preferentially dispersed into leaf litter compared with remaining unsheltered on bare soil; no clear preference among leaf litter types was found. In the second year, however, no clear differences were found among leaf litter types and bare soil. Means of daily minimum temperatures under leaf litter were at least 3.0 ± 0.9 °C (SE) warmer and generally less variable than ambient conditions. While high mortality in both studies illustrates that more work must be done to fully understand overwintering survival, limited survival through potentially lethal conditions in the first-year study nonetheless emphasizes the possibility of populations persisting and rebounding in the following spring. Furthermore, our study highlights the potential for stink bugs to persist in areas with lethal ambient temperatures by dispersing into widely available substrates.

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.

High-quality genome of the zoophytophagous stink bug, Nesidiocoris tenuis, informs their food habit adaptation.

The zoophytophagous stink bug, Nesidiocoris tenuis, is a promising natural enemy of micro-pests such as whiteflies and thrips. This bug possesses both phytophagous and entomophagous food habits, enabling it to obtain nutrition from both plants and insects. This trait allows us to maintain its population density in agricultural fields by introducing insectary plants, even when the pest prey density is extremely low. However, if the bugs' population becomes too dense, they can sometimes damage crop plants. This dual character seems to arise from the food preferences and chemosensation of this predator. To understand the genomic landscape of N. tenuis, we examined the whole genome sequence of a commercially available Japanese strain. We used long-read sequencing and Hi-C analysis to assemble the genome at the chromosomal level. We then conducted a comparative analysis of the genome with previously reported genomes of phytophagous and hematophagous stink bugs to focus on the genetic factors contributing to this species' herbivorous and carnivorous tendencies. Our findings suggest that the gustatory gene set plays a pivotal role in adapting to food habits, making it a promising target for selective breeding. Furthermore, we identified the whole genomes of microorganisms symbiotic with this species through genomic analysis. We believe that our results shed light on the food habit adaptations of N. tenuis and will accelerate breeding efforts based on new breeding techniques for natural enemy insects, including genomics and genome editing.

Adaptive changes in pheromone production and release under rearing conditions in stink bugs.

Healthy cultures of arthropods are important for pest management programs (e.g. biocontrol). Little is known about how rearing conditions may affect pheromonal interactions. We investigated how rearing histories and densities affect pheromone emission/production in two stink bug species (Hemiptera: Heteroptera), the predatory bug Arma custos, a biocontrol agent, and the bean bug Riptortus pedestris, a pest on legume crops. Nymphs from newly established laboratory colonies of both species produced higher amounts of the defense (dispersal) compound, 4-oxo-(E)-hexenal (OHE), in the presence of conspecific nymphs. Also, when two or more A. custos males were placed together, the dorsal abdominal glands (DAGs) ceased to release aggregation pheromone, whereas the metathoracic glands (MTGs) increased the emission of defensive odors. These changes resulted from exposure to conspecific pheromone odors, as confirmed by exposing bugs to pheromone standards. Hence, pheromone emissions in these stink bugs are readily changed in response to the odors of conspecifics, which may become a problem after long-term rearing. Indeed, an old laboratory colony of A. custos (~30 generations) exhibited less-developed DAGs and reduced pheromone production. Instead, males released significantly more defensive odors from the enlarged MTGs. Furthermore, long-term rearing conditions appeared to favor nymphs that were able to share space with conspecifics by releasing less OHE, which has not yet occurred in the new laboratory colonies. Rearing density affects pheromone release in newly established laboratory colonies of stink bug species, whereas long-term rearing results in new pheromonal compositions coinciding with adaptive changes in gland development. © 2023 Society of Chemical Industry.

The fishbone diagram analysis to know the factors that influence the decreasing interest of farmers in the cultivation of soybean

Soybean crop productivity in The Pracimantoro District ranked second in Wonogiri Regency in 2021. However, over time the stability of production has decreased. One thing that causes the decline in soybean production in Pracimantoro District is the decreased interest of farmers in cultivating. This study aimed to determine the factors causing the declining interest of farmers in planting soybeans. The research location was conducted in Pracimantoro District, Wonogiri Regency. The data in this study are primary data and secondary data. Primary data is data are taken directly from the research location through direct observation at the location, interviews with relevant stakeholders, and filling out questionnaires. Secondary data is obtained through agencies related to this research, tabulated and descriptive, and literature searches supporting this research. Analysis method of data using the fishbone diagram. The results showed that the factors that influence the decline in farmers' interest in cultivating soybeans are sources of plant pest and disease risks, sources of input risk and soybean production techniques and sources of risk in the business environment. Some pests and diseases that often arise and attack soybean commodities are leaf spot, whitefly, caterpillar/pod caterpillar, leafhopper, stink bug, bacterial wilt and javelin/ladybug. The Risks from nature is that high rainfall and changing climatic conditions also make it difficult for farmers to grow soybeans. The risk from the production input sector is the unstable quality, quantity, and price of seeds, pesticides and fertilizers. Moreover, other influencing factors exist, such as the entry of imported soybeans, price games at middlemen, the absence of a lower price limit for local soybeans, and post-harvest limitations.

Identification of neuropeptides and their G protein-coupled receptors in the predatory stink bug, Arma custos (Hemiptera: Pentatomidae).

The predatory stink bug Arma custos has been selected as an effective biological control agent and has been successfully massly bred and released into fields for the control of a diverse insect pests. As a zoophytophagous generalist, A. custos relies on a complex neuropeptide signaling system to prey on distinct food and adapt to different environments. However, information about neuropeptide signaling genes in A. custos has not been reported to date. In the present study, a total of 57 neuropeptide precursor transcripts and 41 potential neuropeptide G protein-coupled receptor (GPCR) transcripts were found mainly using our sequenced transcriptome data. Furthermore, a number of neuropeptides and their GPCR receptors that were enriched in guts and salivary glands of A. custos were identified, which might play critical roles in feeding and digestion. Our study provides basic information for an in-depth understanding of biological and ecological characteristics of the predatory bug and would aid in the development of better pest management strategies based on the effective utilization and protection of beneficial natural enemies.

Seasonal Analysis of Yield and Loss Factors in Bt Soybean Crops in North Brazil

Tropical crops face significant challenges from abiotic and biotic stressors, resulting in substantial losses. This study aimed to assess the yield and losses in Bt soybean crops in Tocantins state, northern Brazil, during the 2017/2018 and 2018/2019 growing seasons. We monitored and estimated yield losses and their contributing factors in commercial fields, spanning dry and rainy seasons, from planting to harvest. Our findings revealed that crop yields remained consistent between the dry season (4349.85 kg/ha) and the rainy season (4206.51 kg/ha). Similarly, the overall yield loss showed no significant variation between seasons, with values of 902.86 kg/ha (dry) and 1007.92 kg/ha (rainy). Nevertheless, the factors contributing to these losses exhibited season-dependent variations. We observed higher plant mortality rates during the dry season, whereas insects (particularly stink bugs) and fungi were the primary contributors to grain yield losses during the rainy season. Conversely, losses due to flower abortion and pod malformation remained relatively consistent between the two seasons. Our study underscores the increase in soybean yield in one of Brazil’s agricultural frontiers. While overall yield and losses remained stable between dry and rainy seasons, the distinct seasonal patterns influencing yield losses call for nuanced and season-specific strategies in sustainable crop management.

Bt Soybean Cry1Ac Does Not Affect Development, Reproduction, or Feeding Behavior of Red-Banded Stink Bug Piezodorus guildinii (Hemiptera: Pentatomidae).

Bt soybean cultivation is increasing worldwide. The Cry1Ac protein expressed in Bt soybean efficiently controls several lepidopteran pests. The stink bug, Piezodorus guildinii (Westwood), a major pest for soybean in the Americas, is not controlled by Bt crops, although possible sub-lethal effects may occur. Even if there were no negative effects for sting bug, ingesting toxins could affect its bio-controllers. We tested through ELISA detection if P. guildinii ingests Cry1Ac from Bt soybean and possible effects on its development, reproduction, survival, and feeding behavior. Biological traits were evaluated under controlled conditions of nymphs and adults feeding on pods of near-isogenic cultivars DM5958iPRO (Bt) and DM59i (non-Bt). Feeding behavior was recorded using an AC-DC electropenetrography (EPG) device. Results indicated that P. guildinii ingested the Cry1Ac protein; however, nymphal period and accumulated survival percentage did not differ between cultivars. Feeding on Bt soybean pods did not affect fecundity (i.e., number of egg masses and eggs/female) nor egg viability. Different feeding behaviors were only detected on the pathway phase (stylet penetration into plant tissue), which was more pronounced in the Bt cultivar. However, the total duration of the feeding activities on seeds was numerically higher (ca. 2X) on Bt plants compared to non-Bt. This is the first study to demonstrate that P. guildinii does ingest the Cry1Ac protein and excrete it without being absorbed, probably explaining the lack of direct adverse effects on its biological parameters. EPG could indicate that Bt soybean plants might be less palatable than non-Bt to red-banded stink bug.

The indirect effect of nectar-inhabiting yeasts on olfactory responses and longevity of two stink bug egg parasitoids

Adult parasitoids are well known to feed on sugar-rich resources such as floral nectar. Recently, an increasing body of evidence has shown that nectar is ubiquitously colonized by microorganisms and, as a consequence, microbial metabolic activity can affect several traits of floral nectar. Yet, how the fermentation of nectar by yeasts impacts the olfactory responses and performance of parasitoids is largely understudied, especially in the case of egg parasitoids. In this study, we investigated whether fermentation by the nectar yeasts Metschnikowia gruessii and M. reukaufii affects the olfactory responses of Trissolcus basalis and Ooencyrtus telenomicida, two egg parasitoid species associated with the southern green stink bug Nezara viridula. We also investigated how yeast fermentation affects the longevity and survival of the egg parasitoids. Results of static four-chamber olfactometer tests showed that nectar fermented by M. gruessii (but not by M. reukaufii) was attractive to both egg parasitoid species, whereas no significant yeast-mediated effects were found in terms of wasp longevity. Gas chromatography coupled with mass spectrometry (GC-MS) showed a clear separation of the volatile profiles among M. gruessii, M. reukaufii and non-fermented control nectar supporting the results of the insect bioassays. The results of our study highlight the need to consider the role of microbes when studying interactions between flower nectar and egg parasitoids and could have implications from a conservation biological control perspective.

First report: &lt;em&gt;Spermatodes variolosus&lt;/em&gt; (Walker, 1867) in Indian rice ecosystem along with taxonomy of pentatomid bugs in Terai rice fields, West Bengal, India

Pentatomid bugs, commonly known as stink bugs, are typically herbivorous insects known for their piercing-sucking feeding habits on crops and wild plants. Among these stink bugs, Spermatodes variolosus (Walker, 1867) stands out as the smallest species, measuring 2.6-2.9 mm, and is also known to be phytophagous. In this study, we report the presence of seven species from six different genera of stink bugs in the rice fields of Cooch Behar, West Bengal. Notably, this research marks the first documented occurrence of Spermatodes variolosus (Walker, 1867) in the rice ecosystem of India, raising concerns about its potential pest status. Furthermore, this study includes taxonomic keys for the six genera identified.