Green Stink Bug Research Articles

Kaolin nano-powder effect on insect attachment ability

The present study investigates under controlled conditions the effect of kaolin particle film on reduction of insect attachment ability. Two economically important polyphagous insect pests characterized by different attachment devices were tested, the Southern green stink bug Nezara viridula (Heteroptera: Pentatomidae) and the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae). We performed traction force experiments with females pulling on treated (covered with kaolin particle film) and untreated (control) natural (leaf surfaces with different morphological traits) and artificial (hydrophilic and hydrophobic glass) surfaces. The data demonstrated that insect adhesion is heavily affected by kaolin particle film in both tested species. The degree of reduction of insect adhesion to the treated substrates compared with the untreated ones differed according to the kind of treated substrate owing to its initial wettability and morphology (presence of trichomes). To unravel the insect adhesion reduction mechanism of kaolin particle film, we evaluated the safety factor for females before and after walking on treated surfaces and analyzed under cryo-SEM the tarsal attachment devices of N. viridula and C. capitata after walking on treated surfaces. We observed contamination by the kaolin nanoflakes in both the smooth pads of the bug and the hairy pads of the fly. The present study can help to better understand the mechanism of action of kaolin particle film and can contribute to develop future physical control barriers against pest insects, particularly relevant owing to the need to reduce the negative impacts of pesticides on environment and human health.

Heritable Gammaproteobacterial Symbiont Improves the Fitness of Brachynema germari Kolenati (Hemiptera: Pentatomidae).

The pistachio green stink bug, Brachynema germari Kolenati, is an abundant and economic insect pest in most pistachio-growing regions. Some physiological and ecological features of this pest have been studied, but the microbiological nature of symbiotic bacteria and biological aspects of this host-symbiont interaction have been poorly understood. In the present study, we explored the host-associated environment, phylogeny, and acquisition features of the bacterial symbiont of the insect. Furthermore, the importance of the symbiont on the biological (i.e., lifespan, stage composition, and body weight) and behavioral characteristics (i.e., resting/wandering behaviors of the newborn nymphs) of the host were investigated. We found that a rod-shaped gammaproteobacterium was persistently colonized the fourth midgut region of the insect. Molecular phylogenetic and fluorescence in situ hybridization analyses strongly suggest that this symbiont should be placed in the genus Pantoea of the Enterobacteriales. Egg surface sterilization resulted in the aposymbiotic insects suggesting the vertical transmission of symbiont via egg surface smearing upon oviposition. Symbiotic and aposymbiotic B. germari showed no significant differences in the wandering behaviors of the first nymphal stages, whereas the symbiont-free insects exhibited retarded growth, lower longevity, and adult body weight. Taken together, these data provide a better understanding of the relationship between the bacterial symbiont and B. germari and demonstrate that the insect is heavily affected by the deprival of its gut symbionts.

Trissolcus japonicus (Hymenoptera: Scelionidae) Causes Low Levels of Parasitism in Three North American Pentatomids Under Field Conditions.

Trissolcus japonicus (Ashmead), an Asian parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), was first detected in North America in 2014. Although testing in quarantine facilities as a candidate for classical biological control is ongoing, adventive populations have appeared in multiple sites in the United States, Canada, and Europe. Extensive laboratory testing of T. japonicus against other North American pentatomids and H. halys has revealed a higher rate of parasitism of H. halys, but not complete host specificity. However, laboratory tests are necessarily artificial, in which many host finding and acceptance cues may be circumvented. We offered sentinel egg masses of three native pentatomid (Hemiptera: Pentatomidae) pest species (Chinavia hilaris (Say), Euschistus conspersus Uhler, and Chlorochroa ligata (Say)) in a field paired-host assay in an area with a well-established adventive population of T. japonicus near Vancouver, WA. Overall, 67% of the H. halys egg masses were parasitized by T. japonicus during the 2-yr study. Despite the ‘worst case’ scenario for a field test (close proximity of the paired egg masses), the rate of parasitism (% eggs producing adult wasps) on all three native species was significantly less (0.4–8%) than that on H. halys eggs (77%). The levels of successful parasitism of T. japonicus of the three species are C. hilaris > E. conspersus > C. ligata. The potential impact of T. japonicus on these pentatomids is probably minimal.

The underestimated role of pest pentatomid parasitoids in Southern South America

Stink bugs are pests of economic importance of extensive crops (commodities) in the Neotropics, particularly in Southern South America. They are abundant, have a broad geographical distribution, and cause severe damage. Main species include the Neotropical brown-stink bug, Euschistus heros (F.), the red-banded stink bug, Piezodorus guildinii (Westwood), the Southern green stink bug, Nezara viridula (L.), the green-belly stink bugs, Dichelops furcatus (F.), and D. melacanthus (Dallas), and the brown-winged stink bug, Edessa meditabunda (F.). The management of these pest species on crops is complex because they can cause economic damage in low numbers, and it is difficult to control by the commonly used insecticides. Therefore, biological control appears as the most important tactic to be implemented in stink bug management programs. Among the many natural enemies present on the various agroecosystems, egg parasitoids (Hymenoptera) and parasitoids of adult stink bugs (Diptera and Hymenoptera) are the most promising groups to be exploited as biological control agents of pest species. Despite attempts in the past, implementation of biological control of stink bugs on major commodities in Southern South America still remains at a low level of adoption, and its high potential is, generally, underestimated. In this review article, we present extensive data from the literature on the two main groups of biological control agents referred above. Moreover, we discuss ways to promote biological control as the most important tactic to manage stink bugs in Southern South America.

Female competition for availability of males in insects: the Nezara viridula (Linnaeus, 1758) model.

Multimodal communication in solitary stinkbugs enables them to meet, mate and copulate. Many plant-dwelling species exchange information during the calling phase of mating behavior using substrate-borne vibratory signals. A female-biased gender ratio induces rivalry and competition for a sexual partner. Female competition for males, first described among Heteroptera in three stinkbug species, revealed species specific differences and opened the question of plasticity in individually emitted temporal and frequency signal characteristics during calling and rival alternation. To address this question and gain an insight into the mechanisms underlying stinkbug female rivalry, we compared the characteristics of alternated signals in the southern green stinkbug Nezara viridula (Linnaeus, 1758) (Hemiptera: Pentatomidae). Compared to male rivalry, female rivalry is more complex, lasts longer and runs through successive phases by a combination of different song types. The male pheromone triggers alternation between females, producing song pulses that occasionally overlap each other. One female initiates the rivalry by changing individual pulses into pulse trains of three different types. The competing female alternates with pulses of changed temporal characteristics at lower levels of rivalry and by varying the frequency characteristics of pulse trains at higher levels. During female rivalry, the male either stops responding or occasionally emits calling and courtship signals in response to the female that has produced signals of steady temporal characteristics. Female rivalry shows complex and species specific patterns of information exchange at different levels with a broad-range variation of temporal and frequency characteristics of, until now, unidentified vibratory emissions.

Pathogenicity and virulence of entomopathogenic nematodes against Dichelops melacanthus Dallas (Hemiptera: Pentatomidae)

Infestations of Dichelops melacanthus (Dallas; Hemiptera: Pentatomidae) in corn and wheat in Brazil, and the subsequent damage, have increased in recent years, mainly owing to this insect’s ability to survive the off-season. The control of this insect is mainly carried out with chemical insecticides, but the development of alternative methods, such as biological control, can contribute to a more sustainable management. Thus, the objective of this study was to evaluate the potential of entomopathogenic nematodes (EPNs) for the control of D. melacanthus. A selection test was performed with 15 isolates of genera Steinernema and Heterorhabditis regarding their pathogenicity and virulence on adults of D. melacanthus. Concentration (10, 20, 40, 50, and 100 infective juveniles (IJs)/cm2) and greenhouse tests were carried out only with the Steinernema feltiae isolate (IBCB-n 47). All experiments were conducted in a completely randomized design. The selection test data were submitted to the Scott-Knott averages test (P ? 0.05), and those from the greenhouse test to the Student's t-test. The results of the concentration assay were subjected to regression analysis. All isolates showed pathogenicity and virulence in adults of D. melacanthus. The isolates GL (Heterorhabditis amazonensis), IBCB-n27 (Steinernema sp.), and RSC05 (H. amazonensis) were the most virulent (80.0, 82.0, and 88.0% mortality, respectively). The higher concentrations of S. feltiae (50 and 100 IJs/cm²) were responsible for the highest mortality rates of green belly stink bug (88.0 and 86.0%, respectively). In the greenhouse test, S. feltiae caused higher mortality (38%) than the control.

Candidate genes coding for odorant binding proteins and chemosensory proteins identified from dissected antennae and mouthparts of the southern green stink bug Nezara viridula

The southern green stink bug Nezara viridula (Hemiptera: Pentatomidae) is a highly polyphagous pest that can significantly impact many major crops worldwide. Insect odorant binding proteins (OBPs) and chemosensory proteins (CSPs) transport chemicals and play critical roles in chemoreception. Studies on N. viridula OBPs and CSPs should increase our overall understandings on chemosensory systems and chemical ecology of stink bugs, which may lead to improved pest control. In this study, we identified candidate genes encoding putative OBPs and CSPs in N. viridula by generating transcriptomes from dissected antennae and mouthparts. In total, the 42 unigenes were identified coding for OBPs (34 Classic OBPs and eight Plus-C OBPs) and 13 unigenes coding for CSPs. Expression profiles of OBP- and CSP -encoding genes were compared between antennae and mouthparts based on FKPM values. Candidates for antenna-predominant OBPs and CSPs were selected for real-time quantitative PCR analyses. Analyses of tissue expression profiles revealed that 17 OBP-encoding genes, and four CSP genes were primarily expressed in antennae, suggesting their putative roles in perception of volatiles. The sex-biased expression patterns of these antenna-predominant genes suggested that they may have important functions in reproduction of the insect. This is a systematic analysis on OBPs and CSPs in a stink bug, providing a comprehensive resource for future functional studies not only for N. viridula, but also for other stink bugs as well.

The Cotton Boll: Temporal Susceptibility of the Boll Wall to Stylet Penetration by Hemipteran Pests

Cotton (Gossypium hirsutum L.) is a high‐value cash crop that is injured by various hemipteran insects, including lygus bugs (mirids) and stink bugs (pentatomids). Stink bugs can transmit pathogens that cause seed and boll rot of cotton, and lygus bugs can also transmit pathogens. However, the temporal susceptibility to breaching of the boll wall by stink bugs and related species was unknown. Our objective was to compare known estimates of stylet penetration for mirids (Lygus lineolaris Palisot de Beauvois and Pseudatomoscelis seriatus Reuter) and pentatomids [Chinavia hilaris Say, Euschistus obscurus (Palisot), Euschistus servus (Say), Euschistus tristigmus (Say), Nezara viridula (L.), Oebalus pugnax (F.), Piezodorus guildinii Westwood, and Thyanta custator accerra McAtee] against observed minimum boll wall thickness in multiple entries from four Gossypium species to determine the time at which bolls initially become susceptible to stylet penetration. Results show that P. seriatus could not breach the boll wall. Lygus lineolaris could breach the wall at ≤7 d after flowering in G. herbaceum L. and in select entries of G. hirsutum. All the pentatomids could breach the boll wall at 1 d after flowering, and virtually all could continue to breach the wall throughout the entire production season. Monitoring efforts for stink bugs may need to be implemented at boll set to mitigate introduction of pathogens and yield losses given the season‐long susceptibility to stink bugs.

Community Composition, Abundance, and Phenology of Stink Bugs (Hemiptera: Pentatomidae) in Soybean in the North Central Region of the United States

Stink bugs (Hemiptera: Pentatomidae) are an increasing threat to soybean (Fabales: Fabaceae) production in the North Central Region of the United States, which accounts for 80% of the country's total soybean production. Characterization of the stink bug community is essential for development of management programs for these pests. However, the composition of the stink bug community in the region is not well defined. This study aimed to address this gap with a 2-yr, 9-state survey. Specifically, we characterized the relative abundance, richness, and diversity of taxa in this community, and assessed phenological differences in abundance of herbivorous and predatory stink bugs. Overall, the stink bug community was dominated by Euschistus spp. (Hemiptera: Pentatomidae) and Chinavia hilaris (Say) (Hemiptera: Pentatomidae). Euschistus variolarius (Palisot de Beauvois) (Hemiptera: Pentatomidae), C. hilaris and Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) were more abundant in the northwestern, southeastern and eastern parts, respectively, of the North Central Region of the United States. Economically significant infestations of herbivorous species occurred in fields in southern parts of the region. Species richness differed across states, while diversity was the same across the region. Herbivorous and predatory species were more abundant during later soybean growth stages. Our results represent the first regional characterization of the stink bug community in soybean fields and will be fundamental for the development of state- and region-specific management programs for these pests in the North Central Region of the United States.

Spatial Patterns and Sequential Sampling Plans for Estimating Densities of Stink Bugs (Hemiptera: Pentatomidae) in Soybean in the North Central Region of the United States.

Stink bugs are an emerging threat to soybean (Fabales: Fabaceae) in the North Central Region of the United States. Consequently, region-specific scouting recommendations for stink bugs are needed. The aim of this study was to characterize the spatial pattern and to develop sampling plans to estimate stink bug population density in soybean fields. In 2016 and 2017, 125 fields distributed across nine states were sampled using sweep nets. Regression analyses were used to determine the effects of stink bug species [Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and Euschistus spp. (Hemiptera: Pentatomidae)], life stages (nymphs and adults), and field locations (edge and interior) on spatial pattern as represented by variance-mean relationships. Results showed that stink bugs were aggregated. Sequential sampling plans were developed for each combination of species, life stage, and location and for all the data combined. Results for required sample size showed that an average of 40-42 sample units (sets of 25 sweeps) would be necessary to achieve a precision of 0.25 for stink bug densities commonly encountered across the region. However, based on the observed geographic gradient of stink bug densities, more practical sample sizes (5-10 sample units) may be sufficient in states in the southeastern part of the region, whereas impractical sample sizes (>100 sample units) may be required in the northwestern part of the region. Our findings provide research-based sampling recommendations for estimating densities of these emerging pests in soybean.

Primer registro de una planta hospedante para Chinavia chilensis Grazia, Schwertner & Ferrari (Heteroptera: Pentatomidae)

Abstract. The first hostplant record on Prosopis tamarugo (Fabaceae) is given for the Chilean green stink bug Chinavia chilensis . Observations were made in San Pedro de Atacama, Antofagasta Region, Chile. It was recorded that the females oviposite on the three. Later, nymphs develop on the fruits. The significance of this finding is discussed and it is concluded that C. chilensis may be highly specialized to feed on this vegetal species.

Density and Egg Parasitism of Stink Bugs (Hemiptera: Pentatomidae) in Mimosa

Stink bugs (Hemiptera: Pentatomidae) are primary pests in most fruit, vegetable, grain, and row crops worldwide. The polyphagous habits of these pest species compels them to forage within and between closely associated non-crop and crop habitats across farmscapes in response to changing food resources. The exotic mimosa tree, Albizia julibrissin Durazz (Fabaceae), commonly grows in thickets along roadsides and in woodlands adjacent to agricultural crops across the southeastern USA. Thus, the objective of this study was to determine if mimosa was a host plant of stink bugs in southwest Georgia. Chinavia hilaris (Say) (Hemiptera: Pentatomidae) fed and developed on mimosa during early Jul through mid-Aug. Nymphs and adults of C. hilaris fed more frequently on fruit than on leaves of mimosa. Other stink bugs viz., Euschistus servus (Say), E. tristigmus (Say), E. obscurus (Palisot), Nezara viridula (L.), Thyanta custator custator (F.), and Loxa flavicollis (Drury) (all Hemiptera: Pentatomidae), also were detected on mimosa, but only as adults feeding on fruit. Trissolcus edessae Fouts (Hymenoptera: Scelionidae) was the most prevalent parasitoid of C. hilaris eggs on mimosa, but Anastatus reduvii (Howard) (Hymenoptera: Eupelmidae) also emerged from eggs of this stink bug. Overall, 46.6% of the C. hilaris eggs found on mimosa were parasitized. In conclusion, C. hilaris is the primary stink bug species developing on mimosa in southwest Georgia, serving as a potential source of this stink bug into nearby crops.

Stink bug rostrum length vs. stylet penetration potential

AbstractStink bugs (Hemiptera: Pentatomidae) and related species continue to plague cotton, Gossypium hirsutum L. (Malvaceae), worldwide. Stink bugs utilize their stylets (housed within the rostrum) to feed upon cotton bolls and transmit pathogens that cause seed and boll rot of cotton. Stylet penetration potential of stink bugs is influenced by species and recent observations indicated a phenomenon whereby stink bugs with shorter rostra yielded deeper stylet penetration estimates. The objective of this study was to elucidate the relationship between rostrum length and known stylet penetration estimates for two pairs of similar‐sized pentatomid species: Chinavia hilaris (Say) vs. Euschistus servus (Say), and Oebalus pugnax (Fabricius) vs. Piezodorus guildinii Westwood. For each species, individual rostral segments were measured to yield total lengths, and measurements were compared against known stylet penetration estimates. Chinavia hilaris and P. guildinii have longer rostra than E. servus and O. pugnax, respectively, yet E. servus and O. pugnax yielded deeper stylet penetration estimates. Deeper stylet penetration by species with shorter rostra can be attributed to differences in the lengths of rostral segments 1 and 2. Euschistus servus and O. pugnax each had significantly longer rostral segments 1 and 2 than C. hilaris and P. guildinii, respectively. Also, the cumulative lengths of rostral segments 1 and 2 comprised a higher overall proportion of the entire rostrum length in E. servus and O. pugnax vs. C. hilaris and P. guildinii, respectively. Rostral segments 1 and 2 are instrumental in the feeding mechanics of these phytophagous species; it is clear that their greater length and their role in stylet penetration model calculations – including the lengths of segments 3 and 4 – override the presumption that total rostrum length equates to stylet penetration potential. This novel finding contributes to the general knowledge of stink bug feeding mechanics.

Brown Marmorated Stink Bug, Halyomorpha halys Ståhl (Insecta: Hemiptera: Pentatomidae)

The brown marmorated stink bug (BMSB), Halyomorpha halys (Ståhl), is a recently introduced pest to the western hemisphere and was first officially reported from Allentown, Pennsylvania in 2001 (Hoebeke and Carter 2003). This stink bug may become a major agricultural pest in North America, similar to the southern green stink bug, Nezara viridula (L.). Both species are polyphagous pests of various crops, but the exact potential impact of BMSB is currently unknown until it is detected in agricultural areas. However, in eastern Asia where the BMSB is native or indigenous, it is a pest on fruit trees and soybeans. This document is EENY-346, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: April 2005.
 EENY346/IN623: Brown Marmorated Stink Bug, Halyomorpha halys (Stål) (Insecta: Hemiptera: Pentatomidae) (ufl.edu)

Predation on stink bugs (Hemiptera: Pentatomidae) in cotton and soybean agroecosystems.

Stink bugs (Hemiptera: Pentatomidae) are significant pests of cotton and soybeans in the southeastern United States with annual control costs exceeding $14 million in these crops. Three of the most prominent stink bug pests are the southern green (Nezara viridula), brown (Euschistus servus) and green (Chinavia hilaris) stink bugs. To determine trophic linkages between generalist arthropod predators and these pests, species-specific 16S molecular markers were designed and used to detect the presence of prey DNA in predator gut-contents. Over 2700 predators were collected over two growing seasons in cotton and soybean in southern Georgia in 2011 and 2012 and screened for stink bug DNA. Trophic linkages were analyzed relative to prey availability, crop type and field location. The frequency of stink bug DNA in predator guts was negligible on E. servus (0.23%) and C. hilaris (0.09%). Overall gut content detection of N. viridula was 3.3% and Geocoris sp. (Hemiptera: Geocoridae), Orius sp. (Hemiptera: Anthocoridae) and Notoxus monodon (Coleoptera: Anthicidae) were the primary predators. This contrasts with previous studies that reported a much more diverse suite of predators consuming stink bugs with much higher frequency of gut-content positives. The discrepancy between studies highlights the need for replicating studies in space and time, especially if the goal is to implement effective and durable conservation biological control in integrated pest management.

Insight into Salivary Gland Proteomes of Two Polyphagous Stink Bugs: Nezara viridula L. and Halyomorpha halys Stål.

The invasive brown marmorated stink bug (BMSB), Halyomorpha halys Stål, and the southern green stink bugs (SGSBs), Nezara viridula L., are widely distributed in Europe, even if the date of introduction and the diet differ. Saliva of Hemipteran pests plays essential roles in the interaction between insects and their host plants. The salivary proteomes of several aphid species have been studied and found to differ according to the species, while no comparative investigation between phytophagous stink bugs has been performed yet. Here, the salivary proteins from two bugs, BMSB and SGSB, are analyzed using LC-MS/MS. Data are available via ProteomeXchange with identifiers PXD011920 and PXD011976. A total of 238 and 305 proteins are identified in salivary glands of BMSB and SGSB, respectively. In comparison with salivary proteome from other Hemiptera, the most striking feature of the salivary gland proteomes of SGSB and BMSB is the similar pattern of protein functions between both species. Some of the proteins are speculated to play a significant role in plant-insect interactions. The results herein provide a framework for future research to elucidate the molecular basis of differential impact of piercing-sucking insects on host plants.

Plant Response and Economic Injury Levels for a Boll-Feeding Sucking Bug Complex on Cotton

Whole-plant cage field experiments were conducted in 2014, 2015, and 2016 to characterize cotton injury from a species complex of boll-feeding sucking bugs represented by the verde plant bug, Creontiades signatus (Distant) (Hemiptera: Miridae), brown stink bug, Euschistus servus (Say), green stink bug, Acrosternum hilare (Say), and redbanded stink bug, Piezodorus guildinii (Westwood) (Hemiptera: Pentatomidae). Field-collected adult bugs were used to infest cotton plants previously maintained free of insect injury. Plants caged in groups of four were infested at mid-bloom and late-bloom for 7 d with four insect densities: 0 (control), 0.25 bugs per plant, 1 bug per plant, and 2 bugs per plant. Species and water stress conditions varied across years, allowing selective within-year comparisons. Response to feeding resulted in boll injury in the form of lint deterioration and cotton boll rot at mid- and late-bloom stages, and in water limiting and non-water limiting conditions. Although plant injury was apparent across a wide range of conditions, subsequent yield decline attributed to insect feeding was seen primarily under water limiting conditions when plants were infested at mid-bloom. For these conditions, significant yield-insect density relationships were used to calculate economic injury levels (EILs) for each species. EILs expressed as bugs per plant from lowest to highest were the brown stink bug (0.29-0.31 bugs per plant), redbanded stink bug (0.33), verde plant bug (0.49), and green stink bug (0.50). Given the variability observed among species, species-specific EILs may be used where the injurious species is known and combined for stink bugs (a common EIL of 0.34 bugs per plant) where multiple species occur. Verde plant bug was less damaging and can be considered separately, but its EIL was generally within a range of values for the boll-feeders encountered.

Gripping ease in southern green stink bugsNezara viridulaL. (Heteroptera: Pentatomidae): Coping with geometry, orientation and surface wettability of substrate

AbstractThe southern green stink bugNezara viridulaL. (Heteroptera, Pentatomidae) is highly polyphagous, preferring apically situated seeds and fruits on more than 150 plant species belonging to over 30 plant families all over the world. This forces them to move over highly variable terrains, including plant stems, leaves, pods and buds, which requires efficient attachment. Stink bugs have long slender legs and feet (tarsi) equipped with paired curved claws, paired soft adhesive pads (pulvilli), and flattened lanceolate hairs (setae), which arise ventrally on the first and second foot segments (tarsomeres). To characterize their attachment abilities on well‐defined test substrates, here we comparatively measured and analyzed the traction forces of bugs walking horizontally and vertically on hydrophilic (water attractive) and hydrophobic (water repellent) glass plates and rods. The latter correspond to the geometry of preferred feeding sites of stink bugs in the field. The results show a clear contribution of tarsal flattened lanceolate hairs to the stink bug's attachment. Higher traction forces are generated on a glass rod than on a glass plate, corresponding to up to individual maximum of 43 times the stink bug's body weight. Substrate hydrophobicity promotes the attachment, while the measured forces are up to eight times lower when tarsal hairs are disabled. The combination of smooth and hairy tarsal pads results in a remarkable attachment ability, which enablesN. viridulato climb unstable apical plant parts, and supports their invasive behavior and global dispersion.

Influence of Pheromone-Baited Traps on Stink Bugs in Cotton.

Stink bugs (Hemiptera: Pentatomidae) are economic pests in fruit, vegetable, grain, and row crops worldwide. Pyramid traps baited with lures of stink bug aggregation pheromones capture these pests in the field, but stink bugs can congregate on plants near traps. Our specific objective was to examine the area of arrestment of stink bugs based on their density on cotton at different distances from pheromone-baited traps. We used lures of the aggregation pheromone of Euschistus spp., methyl (2E,4Z)-2,4-decadienoate (MDD), and Plautia stali Scott, methyl [2E,4E,6Z]-2,4,6-decatrienoate (MDT). Overall, Euschistus servus (Say), Euschistus tristigmus (Say), Chinavia hilaris (Say), and Nezara viridula (L.) were the main stink bug species on cotton. Over the 3-yr study, adult stink bug density was significantly higher on the row of cotton immediately adjacent to a pheromone-baited trap than on the second and third row from the trap. Stink bug density was significantly lower on the seventh cotton row beyond the trap in 2015, on the fourth, eighth, and 16th rows in 2017, and on the fourth and eighth rows in 2018 compared to the two or three rows nearest the trap. These results indicate that adult stink bugs congregated mainly on the three cotton rows (2.73 m in width) nearest a trap. Management strategies utilizing pheromone-baited traps for stink bug control, such as trap cropping in combination with traps, should take into consideration this area of arrestment.

Structure and biomechanics of the antennal grooming mechanism in the southern green stink bug Nezara viridula

Insects devote a large amount of time to self-groom to remove foreign material, especially from their sensory appendages. Using various microscopy techniques and behavioural experiments on intact and ablated insects, the present study investigates the antennal grooming of the southern green stinkbug Nezara viridula, which represents a serious pest of different crops in most areas of the world. The antennal grooming behaviour encompasses an action of scraping involving the tibial comb complex (tibial comb + fossula) of both forelegs, generally followed by the tibial comb complex grooming of one leg using the tarsal hairy adhesive pad of the opposite leg (rubbing). From our observations, we can exclude a role in the antennal grooming of other structures such as the foretibial apparatus, while we show an involvement of this last structure in repositioning the stylets inside the labium. The external and internal morphology (cryo-scanning and transmission electron microscopy) and the evidence for the presence of large proportions of the elastic protein resilin (confocal laser scanning microscopy) in some parts of both the tibial comb complex and the foretibial apparatus are shown, and their functional roles are discussed. For the first time we demonstrated here the multipurpose role of the basitarsal hairy adhesive pad that is involved in both antennal grooming and adhesion to the substrate.