Nezara Viridula Research Articles

Nanocarrier mediated delivery of insecticides into tarsi enhances stink bug mortality.

Current delivery practices for insecticide active ingredients are inefficient with only a fraction reaching their intended target. Herein, we developed carbon dot based nanocarriers with molecular baskets (γ-cyclodextrin) that enhance the delivery of active ingredients into insects (southern green stink bugs, Nezara viridula L.) via their tarsal pores. Nezara viridula feeds on leguminous plants worldwide and is a primary pest of soybeans. After two days of exposure, most of the nanocarriers and their active ingredient cargo (>85%) remained on the soybean leaf surface, rendering them available to the insects. The nanocarriers enter stink bugs through their tarsi, enhancing the delivery of a fluorescent chemical cargo by 2.6 times. The insecticide active ingredient nanoformulation (10 ppm) was 25% more effective in controlling the stink bugs thanthe active ingredient alone. Styletectomy experiments indicated that the improved active ingredient efficacy was due to the nanoformulation entering through the insect tarsal pores, consistent with fluorescent chemical cargo assays. This new nanopesticide approach offers efficient active ingredient delivery and improved integrated pest management for a more sustainable agriculture.

Unveiling Detoxifying Symbiosis and Dietary Influence on the Southern Green Shield Bug Microbiota.

The Southern green shield bug, Nezara viridula, is an invasive piercing and sucking pest insect that feeds on crops and poses a threat to global food production. Insects live in close relationships with microorganisms providing their host with unique capabilities, such as resistance to toxic plant metabolites. In this study, we investigated the resistance to and detoxification of the plant metabolite 3-nitropropionic acid by core and transient members of the N. viridula microbial community. Microbial community members showed a different tolerance to the toxin and we determined that six out of eight strains detoxified 3-nitropropionic acid. Additionally, we determined that 3-nitropropionic acid might interfere with the biosynthesis and transport of L-leucine. Moreover, our study explored the influence of diet on the gut microbial composition of N. viridula, demonstrating that switching to a single-plant diet shifts the abundance of core microbes. In line with this, testing pairwise microbial interactions revealed that core microbiota members support each other and repress the growth of transient microorganisms. With this work, we provide novel insights into the factors shaping the insect gut microbial communities and demonstrate that N. viridula harbours many toxin-degrading bacteria that could support its resistance to plant defences.

Species diversity of pests of the suborder of shield bugs (Heteroptera) in agrocenoses of the Lazarevsky district of Sochi, Krasnodar Territory, Russia

Aim. The aim of the work was to study the species diversity of pests of the suborder of shield bugs (Heteroptera) in agrocenoses of the Lazarevsky district of Sochi.This paper presents data on the distribution, abundance and density of Heptoptera pest populations in this location. Heteroptera were gathered twice a month during the growing season (April to October) and weekly in the autumn‐winter period (November to March). The choice of registration date during the growing season was determined by the appearance of the first phytophagous individuals after wintering. Identification of the identified phytophages was carried out in the laboratories of the station according to generally accepted methods.The paper presents data on the distribution, abundance and density of pest populations of the suborder of shield bugs (Heteroptera) in the Lazarevsky district of Sochi, Krasnodar Territory. As a result of this research, the species composition of the most common species of bedbugs in this area has been revealed. The most harmful species noted were: berry shield Dolycoris baccarum Linnaeus, 1758; ornate shield Eurydema ornata Linnaeus, 1758; Green shield Nezara viridula Linnaeus, 1758; ruled shield Graphosoma lineatum Linnaeus, 1758; brown‐marbled bug Halyomorpha halys Stål, 1855; oak lace‐maker Corythucha arcuata Say, 1832; sycamore lace‐maker Corythucha ciliata Say; pear lace‐maker Stephanitis pyri Fabricius and linden bug Oxycarenus lavaterae Fabricius, 1787.As a result of the research undertaken, an increase in the total number of bedbug populations, an expansion of trophic connections, an increase in aggressiveness and a change in the status of individual pest species were revealed.

Detection of damage caused by Nezara viridula on soybean using novel imaging approaches based on computed tomography and image color analysis.

Soybean (Glycine max L.) is an important leguminous plant, in which pests trigger significant damage every year. Important members of this community are insects with piercing-sucking mouthpart, especially the southern green stinkbug, Nezara viridula L.. This insect with its extraoral digestion causes visible alterations (morphological and color changes) in the seeds. We aimed to obtain precise information about the extent and nature of damage in soybeans caused by N. viridula using nondestructive imaging methods. Two infestation conditions were applied: one with controlled numbers of pests (six insects/15 pods) and another with naturally occurring pests (samples collected from the apical part of the plant and samples from whole plants). An intact control group was also included, resulting in four treatment groups. Seed samples were analyzed by computed tomography (CT) and image color analysis under laboratory conditions. According to our CT findings, the damage caused by N. viridula changed the radiodensity, volume, and shape (Solidity) of the soybean seeds during the pod-filling and maturing period. Radiodensity was significantly reduced in all three damaged categories compared to the intact sample; the mean radiodensity reduction range was 49-412 HU. The seed volume also decreased significantly (25%-80% decrease), with a threefold reduction for samples exposed to regulated damage compared to natural ones. The samples exposed to natural damage showed significant but minor reduction in solidity, while samples exposed to regulated damage showed a prominent decrease (~12%). Image color analysis showed that the damaged samples were well distinguishable, and the differences were statistically verifiable. The achieved data derived from our external and internal imaging approaches contribute to a better understanding of the internal chemical processes, and CT analysis helps to understand the alteration trends of the hidden structure of seeds caused by a pest. Our results can contribute to the development of a practically applicable system based on image analysis, which can identify lots damaged by insects.

Researches on feeding behaviors of Nezara viridula (Linnaeus, 1758)(Hemiptera: Pentatomidae) adults in intermittent CO2 applications

In this study, the effects of 3 different doses (430, 600 and 670 ppm) of intermittent CO2 applications on the feeding behaviors of Nezara viridula L. (Hemiptera: Pentatomidae) Adults were determined. As nutritional behavior, the total nutrition duration of adult male and female individuals other than nutrients was examined. As a result of the study, no statistically significant difference was found between the total feeding times of female and male individuals of N. viridula. A statistically significant difference was found between the duration of stay on the nutrients of female and male individuals of N. viridula who received 600 ppm and 670 ppm doses of CO2. The duration of stay on the nutrients of male individuals who received 600 ppm and 670 ppm doses of CO2 was found to be significantly lower than the duration of stay on the nutrients of female individuals. The duration of stay on the nutrients of male individuals who received 670 ppm doses of CO2 was found to be significantly lower than the duration of stay on the nutrients of female individuals. No statistically significant difference was found between the CO2 dose groups of N. viridula and the total feeding times of the control group. A statistically significant difference was found between the CO2 dose groups of N. viridula and the duration of stay apart from the nutrients and the duration of stay on the nutrients of the control group. The duration of stay on the nutrients of individuals exposed to 600 and 670 ppm CO2 doses was found to be significantly lower than the duration of stay on the nutrients of individuals in the control group. In addition, the duration of stay apart from the nutrients of the individuals to whom 600 and 670 ppm CO2 doses were applied was found to be significantly higher than the duration of stay apart from the nutrients of the individuals in the control group. As a general result of this study, it was determined that as the application dose increased, the feeding behaviors of male and female individuals changed, male individuals reacted more to dose administration and remained on nutrients less than female individuals.

Decision fusion-based system to detect two invasive stink bugs in orchards

Accurate and early detection of insect pests plays an important role in crop protection and pest management in agriculture, especially in orchards. This paper is focused on evaluating and improving the performance of insect detection algorithms by adopting an ensemble approach of artificial neural networks. A set of advanced object detection models including YOLOv8, Faster R-CNN, RetinaNet, SSD, and FCOS were selected, and the models were trained and evaluated on a common dataset representing digital images of different insect species pests. Two classes were considered represented by quite similar invasive stink bugs, Halyomorpha Halys and Nezara Viridula. These architectures were optimized to identify significant peculiarities and variations between reference insects, including size, shape, and color. Each model has been implemented and optimized to achieve the best possible performance before integrating into an ensemble system. By integrating the predictions of these models through a weighted ensemble mechanism that leverages the F1 Score of each model, a more performant global system was developed capable of detecting insect pests with improved performance over individual models. This significant improvement in insect detection highlights the potential of the proposed ensemble system in efficient and rapid insect pest identification, ultimately providing valuable opportunities for implementing crop monitoring technologies. The research highlights the importance of implementing and developing deep-learning technologies for solving specific challenges in agriculture and brings innovative ways of strategic pest management for sustainable agricultural practices.

Neonicotinoid Residues on Filter Paper Lack Insecticidal Activity.

Neonicotinoid insecticides are used against agricultural, forest, and urban insect pests. Evaluation of dry neonicotinoid residues on treated filter paper is a commonly used method to determine the toxicity of active ingredients towards target and non-target organisms. Dry residues of four neonicotinoids, acetamiprid, dinotefuran, imidacloprid, and thiamethoxam, on filter paper did not cause significant levels of mortality in Hippodamia convergens (Guérin-Méneville) (Coleoptera: Coccinellidae) and Nezara viridula (L.) (Hemiptera: Pentatomidae) when compared to paired untreated groups. Conversely, nearly 100% mortality was observed when test insects were exposed to dry neonicotinoid residues on leaf discs and glass plate surfaces. On the other hand, dry residues of the pyrethroid bifenthrin on filter paper, leaf disks, and glass plates killed significantly more test insects when compared to untreated groups. Additional bioassays tested the toxicity of acetamiprid and thiamethoxam by evaluating the toxicity of dry residues on (1) the upper and (2) lower surfaces of treated filter paper, (3) on a glass plate underneath treated filter paper, (4) on the upper surface of treated filter paper treated with insecticide and adjuvant, and (5) dried residues on a glass plate after dipping treated filter paper in water and letting the solvent dry on the inert test surface. The results indicated that neonicotinoid insecticides applied to filter paper were adsorbed. Toxic compounds possibly move in between and binding to paper fibers so that no toxic residues were left on treated surfaces. However, adsorbed insecticides were still biologically active when washed out of filter paper and dried on an inert glass surface. The results reported here clearly demonstrate that the toxicity of neonicotinoid insecticides should not be evaluated using filter paper as a test surface.

The quantity of deposited environmental DNA in plant–arthropod interactions depends on taxon, abundance and interaction time

Abstract Environmental DNA (eDNA) metabarcoding holds great promise as a simple and efficient tool to detect plant–insect interactions. However, the influence of both abiotic and biotic factors on eDNA deposition in these interactions is not well understood. It especially remains to be tested how much eDNA abundances reflect the frequency or intensity of interactions between insects and plants. We experimentally analysed the quantitative deposition of eDNA from three insect species (the southern green stink bug Nezara viridula, the mustard beetle Phaedon cochleariae and the fall armyworm Spodoptera frugiperda) on leaves of two host plants of varying attractiveness: savoy cabbage (Brassica oleracea var. sabauda, preferred host) and tomato (Solanum lycopersicum, less preferred host). We tested for the effects of insect taxonomy, host plant, exposure time and abundances of interacting insects on the plant material. Our data show a clear quantitative ecological signal in eDNA deposition. Insect abundance and interaction time are reflected in the amount of deposited eDNA. Moreover, significantly more eDNA was deposited on cabbage, the preferred host plant. Besides these ecological drivers, a very strong taxonomic eDNA deposition bias between different insect taxa was observed. eDNA detection is strongly influenced by the ecological interactions of the targeted taxa, highlighting the utility of the tool to specifically detect trophic interactions between plants and arthropods. However, taxonomic biases in eDNA deposition preclude comparative analyses of interactions at the community level.

Electrophysiological Responses of Trissolcus japonicus, T. basalis, and T. oenone (Hymenoptera: Scelionidae) to Volatile Compounds Associated with New Zealand Stink Bugs (Hemiptera: Pentatomidae).

Parasitoid biological control agents rely heavily on olfaction to locate their hosts. Chemical cues associated with hosts and non-hosts are known to influence the expression of host preferences and host-specificity. A better understanding of how and why parasitoids attack some species and not others, based on volatile organic compounds associated with potential hosts, can provide key information on the parasitoid's host preferences, which could be applied to pre-release risk assessments for classical biological control agents. Electrophysiological techniques such as electroantennography (EAG) and GC-EAD (gas chromatography coupled with electroantennographic detection) are widely used to identify bioactive semiochemicals. But the application of these techniques to understanding how chemical ecological cues mediate parasitoid host specificity has not been as thoroughly explored. We conducted GC-EAD and EAG studies to identify olfactory-active compounds associated with adult females of nine stink bug species from Aotearoa/New Zealand on the antennae of three closely related parasitoid species: Trissolcus japonicus Ashmead, a pre-emptively (= proactively) approved biocontrol agent against brown marmorated stink bug; T. basalis (Wollaston), a biocontrol agent introduced against Nezara viridula L. in 1949; and T. oenone Johnson, a native Australasian pentatomid parasitoid. Eight compounds associated with stink bugs elicited antennal responses from all three parasitoids, and we were able to identify seven of these. (E)-2-hexenal, (E)-4-oxo-2-hexenal, (E)-2-octenal and (E)-2-decenal generally elicited stronger responses in the three parasitoids, while n-tridecane, n-dodecane, and (E)-2-decenyl acetate elicited weaker responses. We discuss how and why the results from electrophysiological experiments can be applied to non-target risk assessments within biological control programmes.

Predation efficacy of Chrysoperla carnea on two economically important stink bugs

Larvae of the green lacewing Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) are generalist predators feeding on a range of pests in agroecosystems. Little is known about the suitability of stink bugs as prey for lacewing larvae. In the present laboratory study, the predatory efficacy of C. carnea on two economically important stink bugs, Halyomorpha halys (Stål) and Nezara viridula (L.) (Hemiptera: Pentatomidae), was evaluated at three constant temperatures (16, 21, and 26 °C) in different arenas (10-cm diameter dishes with bean pod slices or caged small bean plants). We found that second and third instars of C. carnea readily prey on the first instars of both stink bug species. However, only third instars of C. carnea could successfully kill and feed on second instars of either pentatomid. The complexity of the arena, as well as the life stage of the prey and predator influenced the predation efficacy of C. carnea on stink bug nymphs, whereas temperature did not. The observed predation rates on the early instars of both stink bugs suggest that augmentative releases of C. carnea larvae may have some potential in greenhouse crops, particularly against N. viridula infestations, whereas in open field crops their natural populations may also contribute to pest suppression within the broader predator guild.

New records, diagnostics and preliminary checklist of the superfamily Pentatomoidea (Hemiptera: Heteroptera) from the Comoro Islands

The following species are recorded from the Comoro Islands for the first time: 12 species of Pentatomidae: Pentatominae—Anoano pronotalis Cachan, 1952 (from Mayotte), Antestiopsis clymeneis cf. galtiei (Frappa, 1934) (Mayotte), Bagrada hilaris (Burmeister, 1835) (Mayotte), Bathycoelia rodhaini Schouteden, 1913 (Mayotte), Coquerelia ventralis Horváth, 1904 (Mayotte), Eurysaspis transversalis Signoret, 1851 (Anjouan, Grande Comore, Mayotte), Gadarscama ebenaui Reuter, 1887 (Anjouan, Grande Comore, Mohéli, Mayotte), Lerida annulicornis (Signoret, 1861) (Anjouan, Mayotte), Neoacrosternum validum (Horváth, 1904) (Grand Comore, Mayotte), Nezara viridula (Linnaeus, 1758) (Mayotte), Piezodorus hybneri (Gmelin, 1790) (Mayotte), and Stenozygum mirabile (Signoret, 1861) (Mayotte); two species of Plataspidae—Brachyplatys hemisphaerica (Westwood, 1837) (Mayotte) and Coptosoma maculatum Westwood, 1837 (Mayotte); and one species of Scutelleridae—Hotea denticulata Stål, 1865 (Mayotte). The endemic pentatomine species Bathycoelia cuneifera Bergroth, 1893, syn. nov., is recognized as a junior subjective synonym of the widely distributed African species Bathycoelia thalassina (Herrich-Schäffer, 1844). The lectotype of B. cuneifera is designated herein. The checklist of the Pentatomoidea of Comoro Islands includes six species of Cydnidae, 21 species of Pentatomidae, two species of Plataspidae, one species of Scutelleridae and 1 species of Tessaratomidae. Of these species, six are endemic to the archipelago, 14 species are subendemic (shared with Madagascar and/or Aldabra Atoll), and nine species are widespread, occurring also on the African mainland (including the cosmopolitan pest Nezara viridula and two species of Bathycoelia Amyot & Serville, 1843 from the Guinean area, all three possibly alien to the archipelago). We document an additional eight species (six species of Pentatomidae, one species of each Scutelleridae and Tessaratomidae) that are identified to generic level only (two recorded from Grand Comore, seven from Mayotte, one of them occuring in both islands). Mayotte is the best sampled island, with 28 recorded species, followed by Grande Comore (11 species), Anjouan (six species), and Mohéli (four species). In addition the following new records are provided: Bathycoelia rodhaini from Cameroon, Central African Republic, Gabon and Zambia, Bathycoelia thalassina from Central African Republic and Ethiopia, and Piezodorus hybneri from Angola (Cabinda) and Sierra Leone. The type locality of Eurysaspis transversalis Signoret, 1851, India: Puducherry, is considered an error as the species occurs only in Madagascar and Comoros. The following plant associations are recorded from Mayotte: Bagrada hilaris on Cleome viscosa (Cleomaceae), Eurysaspis transversalis on Senna singueana (Fabaceae), and Piezosternum sp. on Cucumis sativus (Cucurbitaceae) and Mikania capensis (Asteraceae).

Variations in the relative abundance of hemipteran species in different seasons and stages of rice growth depending on weather variations

Rompin has played an active role in Malaysia's rice production for several decades. However, it also faces a threat, particularly from the hemipteran insect pests. There is limited documentation on the abundance of these insects and their relationship with climatic factors. Therefore, this study aimed to determine the abundance of hemipterans in different growth stages and to understand the effects of climatic factors on their population in rice fields. The study was conducted in farmers' rice fields in Rompin, Pahang, Malaysia, during the main and off-season rice planting. Sweep nets, yellow sticky traps, and yellow pan traps were utilized in each plot. Trapped insects were identified based on the rice planting seasons and growth stages. The trends of climatic factors such as rainfall, temperature, light intensity, and wind speed were analysed and correlated with insect abundance. A total of 23,023 individuals belonging to eight families and eleven species of the hemipteran order were recorded. Nine of these species were pests, namely Leptocorisa oratorius, Recilia dorsalis, Nephotettix virescens, N. nigropictus, Amaurochrous dubius, Nilaparvata lugens, Sogatella furcifera, Nezara viridula, and Scotinophara coarctata. The remaining two species were predators, Cyrtorhinus lividipennis and Polytoxus fuscoviftatus. R. dorsalis, N. lugens, S. furcifera, and A. dubius were found in significantly higher numbers and exceptionally high during rice's late vegetative and early reproductive stages. The maximum temperature significantly increased during the main season, while wind speed increased dramatically during the off-season. Wind speed significantly correlated with N. virescens, S. furcifera, L. oratorius, and A. dubius. On the other hand, rainfall exhibited a significant correlation with L. oratorius. Various pest species and their high populations in this study pose a significant threat to plants due to their preferences for different plant parts and strata.

Halyomorpha halys (Hemiptera: Pentatomidae) as the major contributor to early olive drop in northern Italy.

In recent years, a new phenomenon of early olive drop is causing production losses in olive groves throughout northern Italy. To analyze the possible causes, field and laboratory trials were performed to assess the involvement of fungal pathogens and insect pests in this disease. External and internal symptoms of fungal infections or insect-feeding activities were researched. Fungi present in healthy and dislodged olives were investigated. The relationship between olives that fell and Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) infestation was assessed in a controlled infestation trial, and the effectiveness of an insecticidal strategy in reducing early olive drop was tested in open field conditions. A comparable number of fungi, mostly endophytes, were isolated and identified from both healthy and dislodged olives. The damage observed on dislodged olives was primarily ascribed to pentatomids feeding activity. Six stink bugs species were found in olive canopies, that is, the invasive H. halys, which was by far the most abundant, and Acrosternum heegeri Fieber, Nezara viridula (Linnaeus), Palomena prasina (Linnaeus), Piezodorus lituratus (Fabricious), and Rhaphigaster nebulosa (Poda). Halyomorpha halys caused intense fruit drop in the controlled infestation trial, and its infestation level significantly correlated with the number of olives that fell. Native stink bugs, present in much lower population compared to H. halys, could also partially contribute to early drop of olives. Insect proof net significantly reduced the early olive drop disease, while insecticide applications only partially reduced the stink bugs population density and, proportionally, early olive drop.

Root inoculation with beneficial soil microbes enhances indirect plant defences induced by insect feeding and egg deposition

Abstract Plants can respond to insect egg deposition by emitting oviposition‐induced plant volatiles (OIPVs) recruiting parasitoids. The recruitment of carnivore insects in response to egg deposition is considered an indirect defence strategy that is widespread in the plant kingdom. In recent years, there has been increasing evidence showing that microbial colonization can influence the strength of plant responses to insect herbivory, yet no information is available on how beneficial microbes modulate indirect defences induced by insect egg deposition. In this work, we evaluated the effects of inoculation with the beneficial soil fungus Trichoderma harzianum strain T22 on a tritrophic system consisting of tomato, the southern green stink bug Nezara viridula and its associated egg parasitoid Trissolcus basalis. We used Y‐tube olfactometer assays to evaluate the behavioural responses of the parasitoids to OIPVs emitted by plants colonized with beneficial soil microbes. We also used gas chromatography coupled with mass spectrometry (GC–MS) to investigate whether and how root inoculation with T. harzianum T22 affects the chemical composition of induced plant volatiles. In olfactometer assays, we found that root inoculation with T. harzianum T22 enhanced the attraction of the egg parasitoid towards tomato plants induced by N. viridula feeding and oviposition activities. In particular, the egg parasitoid preferred OIPVs emitted by tomato plants previously inoculated with T. harzianum T22 over OIPVs emitted by non‐inoculated plants. Furthermore, chemical analysis showed that root inoculation with T. harzianum T22 resulted in changes in the composition of OIPVs, which was consistent with the behavioural observations. Among the compounds that strongly contribute to the chemical differences between OIPVs from non‐inoculated and inoculated plants, chemical analysis identified green leaf volatiles ((Z)‐3‐hepten‐1‐ol, (E,E)‐2,4‐hexadienal), along with terpenoids (terpinen 4‐ol, α‐tujene and δ‐elemene). Taken together our results indicate that beneficial soil microbes enhance indirect plant defences induced by feeding and oviposition, broadening our understanding of plant responses to insect eggs. Our results underscore the importance of taking into account the role of microorganisms to fully comprehend the intricate interactions among plants, herbivore eggs and their associated egg parasitoids. Read the free Plain Language Summary for this article on the Journal blog.

Differential effects of plant-beneficial fungi on the attraction of the egg parasitoid Trissolcus basalisin response to Nezara viridula egg deposition.

There is increasing evidence that plant-associated microorganisms play important roles in defending plants against insect herbivores through both direct and indirect mechanisms. While previous research has shown that these microbes can modify the behaviour and performance of insect herbivores and their natural enemies, little is known about their effect on egg parasitoids which utilize oviposition-induced plant volatiles to locate their hosts. In this study, we investigated how root inoculation of sweet pepper (Capsicum annuum) with the plant-beneficial fungi Beauveria bassiana ARSEF 3097 or Trichoderma harzianum T22 influences the olfactory behaviour of the egg parasitoid Trissolcus basalis following egg deposition by its host Nezara viridula. Olfactometer assays showed that inoculation by T. harzianum significantly enhanced the attraction of the egg parasitoid, while B. bassiana had the opposite effect. However, no variation was observed in the chemical composition of plant volatiles. Additionally, fitness-related traits of the parasitoids (wasp body size) were not altered by any of the two fungi, suggesting that fungal inoculation did not indirectly affect host quality. Altogether, our results indicate that plant inoculation with T. harzianum T22 can be used to enhance attraction of egg parasitoids, which could be a promising strategy in manipulating early plant responses against pest species and improving sustainable crop protection. From a more fundamental point of view, our findings highlight the importance of taking into account the role of microorganisms when studying the intricate interactions between plants, herbivores and their associated egg parasitoids.

Effects of Beauveria bassiana on the growth and reproductive rates of Nezara viridula

Effects of Beauveria bassiana on the growth and reproductive rates of Nezara viridula

A Review of Host Plant Preferences of Pentatomid Pests from West Bengal

Pentatomid bugs are a group of insects which feed on host plants. They are known to be piercing-sucking type pests of crops in India. In this study we have mainly tried to record Pentatomid pests from West Bengal along with their distribution throughout the state and their interactions with host plant species. The plant family Poaceae is infested by the highest number of Pentatomid pests. There are eleven plant families which are infested by pentatomid species. Among the reported pests of pentatomids viz., Dolycoris indicus Stal and Nezara viridula (Linnaeus) feed on plant species belonging to seven families followed by Bagrada hilaris (Burmeister) which consumes plant species of six families. Pentatomid bugs like Dolycoris baccarum, Eysarcoris ventralis Westwood, Menida versicolor (Gmelin) and Stenozygum speciosum (Dallas) are reported to attack plants from two families.

Biological control potential of two Beauveria bassiana isolates against the stink bugs Nezara viridula L. and Piezodorus guildinii Westwood (Hemiptera: Pentatomidae) in common bean

BackgroundThe stink bugs, Nezara viridula L. and Piezodorus guildinii Westwood (Hemiptera: Pentatomidae) are the most important and widespread species of polyphagous stink bugs in the tropical and subtropical regions of Latin America, which affect the quality and yield of the common bean (Phaseolus vulgaris L.). The use of synthetic chemical insecticides is the major control strategy to manage stink bugs in common beans and alternatives are needed. In this study, mortality and median Lethal Time (LT50) of two Cuban isolates of the entomopathogenic fungus Beauveria bassiana (18 S-O-R and 96 P-O-E), as well as one commercial Cuban isolate (Bb-18), at a concentration of 1 × 108 conidia/ml were evaluated. These evaluations were conducted against both stink bug species using Petri dish bioassays and a semi-field experiment in common beans.ResultsIn Petri dish bioassays, the isolates 18 S-O-R and 96 P-O-E caused 100% mortality of both N. viridula and P. guildinii. This was significantly higher than for isolate Bb-18, which caused 86.3% N. viridula and 81.3% P. guildinii mortality. In the semi-field experiment, when pooling both stink bug species, total mortality after 14 days was 91.3% for 18 S-O-R, 80.0% for 96 P-O-E and 73.8% for Bb-18 isolates. LT50 value for isolate 18 S-O-R tested under laboratory conditions was 6.04 ± 0.18 days for N. viridula and 5.32 ± 0.14 days for P. guildinii at the same concentration of 1 × 108 conidia/ml. LT50 value for isolate 18 S-O-R in semi field was 6.79 ± 0.37 days for N. viridula and 7.71 ± 0.32 days for P. guildinii at 1 × 108 conidia/ml.ConclusionThe study highlights the potential of B. bassiana 18 S-O-R as a promising candidate for control of stink bugs in common bean under tropical conditions as an alternative to conventional chemical insecticides in integrated pest management (IPM) programs. Moving forward, further research should focus on validating the efficacy under diverse field conditions and integrating application methods into practical IPM approaches. Future use of B. bassiana will enhance sustainability and reduce environmental impacts associated with pesticide use.

Insecticide Susceptibilities and Enzyme Activities of Four Stink Bug Populations in Mississippi, USA.

In Mississippi, the Pentatomidae complex infesting soybean is primarily composed of Euschistus servus, Nezara viridula, Chinavia hilaris, and Piezodorus guildinii. This study employed spray bioassays to evaluate the susceptibilities of these stink bugs to seven commonly used formulated insecticides: oxamyl, acephate, bifenthrin, λ-cyhalothrin, imidacloprid, thiamethoxam, and sulfoxaflor. Stinks bugs were collected from soybeans in Leland, MS, USA during 2022 and 2023, as well as from wild host plants in Clarksdale, MS. There was no significant difference in the susceptibility of C. hilaris to seven insecticides between two years, whereas P. guildinii showed slightly increased susceptibility to neonicotinoids in 2023. Among all four stink bug species, susceptibility in 2022 was ranked as P. guildinii ≤ C. hilaris ≈ N. viridula, while in 2023, it was ranked as P. guildinii ≤ C. hilaris ≤ E. Servus. Additionally, populations of E. servus and P. guildinii collected from Clarksdale exhibited high tolerance to pyrethroids and neonicotinoids. Moreover, populations of E. servus and P. guildinii from SIMRU-2022 and Clarksdale-2023 showed elevated esterase and cytochrome P450 activity, respectively. These findings from spray bioassays and enzyme activity analyses provide a baseline for monitoring insecticide resistance in Pentatomidae and can guide insecticide resistance management strategies for Mississippi soybean.

Development, Survival and Reproduction of Nezara viridula (Hemiptera: Pentatomidae) in Sesame Cultivars and Implications for the Management.

Sesame, an oilseed plant with multiple applications, is susceptible to infestations by the stink bug Nezara viridula (Linnaeus, 1758) (Hemiptera: Pentatomidae). This pest suctions the seeds of this plant and injects toxins into them. Possible sources of resistance on sesame cultivars are important to manage this bug. The objective of this study was to evaluate the biological aspects of N. viridula fed on three sesame cultivars aiming to select possible resistance sources for integrated pest management (IPM) programs of this stinkbug. The experimental design used randomized blocks with three treatments and four replications, each with newly emerged N. viridula nymphs fed with sesame capsules of the cultivars BRS Anahí (T1), BRS Morena (T2) and BRS Seda (T3). Two to three green sesame capsules were supplied every two days per group of ten N. viridula nymphs as one replication until the beginning of the adult stage. Adults of this stinkbug were fed in the same manner as its nymphs but with mature sesame capsules until the end of the observations. Survival during each of the five instars and of the nymph stage of N. viridula with green sesame capsules was similar between cultivars, but the duration of the nymph stage was shorter with green capsules of the BRS Morena than with those of the BRS Anahí. The oviposition period, number of egg masses and eggs per female, and the percentage of nymphs hatched were higher with mature capsules of the sesame cultivar BRS Anahí and lower with the others. Nymphs did not hatch from eggs deposited by females fed mature seed capsules of the sesame cultivar BRS Morena, which may indicate a source of resistance against this stinkbug in this cultivar. The worldwide importance of N. viridula to sesame cultivation makes these results useful for breeding programs of this plant aiming to develop genotypes resistant to this bug. In addition, the BRS Morena is a cultivar already commercially available and can be recommended in places where there is a history of incidence of N. viridula, aiming to manage the populations of this pest.