Comparative morphology of immature stages of four species of Chinavia (Hemiptera, Pentatomidae), with a key to the species of Rio Grande do Sul, Brazil.
ABSTRACT: Chinavia Orian (1965) is one of the most diverse genera of Pentatomidae, distributed in the Afrotropical, Neotropical and Nearctic Regions. Thirty-two species are recorded for Brazil, some of them having potential economic impact because they are found on crops and referred to as pests. The morphology of the five nymphal instars of Chinavia armigera (Stål, 1859), Chinavia aseada (Rolston, 1983), Chinavia brasicola (Rolston, 1983) and Chinavia runaspis (Dallas, 1851) are described here. Through a comparative study, identification keys were developed to allow an early identification of the 12 Chinavia species of Rio Grande do Sul.
Project description:California currently produces about a quarter of the world's pistachios. Pistachio nuts are susceptible to feeding by stink bugs and leaffooted bugs; therefore, the invasive presence of the highly polyphagous brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a concern to California pistachio growers. We aimed to assess the potential of H. halys to cause yield loss and nut damage to pistachios, which had not yet been assessed in the field. Over two years, terminal branch ends with pistachio clusters were enclosed in organdy cages from spring to fall and exposed to either H. halys, the native stink bug Chinavia hilaris Say (Hemiptera: Pentatomidae), or leaffooted bug Leptoglossus zonatus (Dallas) (Hemiptera: Coreidae), for 4-7-day feeding periods at different times of the season. We found that H. halys adults cause more epicarp lesions (external damage) when recorded at harvest time than the native species. They did not, however, cause more kernel necrosis (internal damage) than the two native species tested, which is a more relevant damage criterion for commercial production. There were no differences among insect species for any other recorded damage criteria. We conclude that H. halys could cause similar damage as the native species but note that H. halys population densities in California are still low and future damage levels will be dependent on this pest's population density.
Project description: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.
Project description:Background:Trissolcus Ashmead (Hymenoptera: Scelionidae) is a cosmopolitan genus of egg-parasitoid wasps associated with stink bugs (Pentatomidae, Scutelleridae, Urostylididae), many of which are important insect pests. Documentation of host associations for these wasps, which we here provide via museum specimens, can support their use as biological control agents of invasive stink bugs. New information:The hosts of seven Trissolcus species are reported from China: Trissolcus cultratus (Mayr) (hosts: Hippotiscus dorsalis Stål, Pentatomidae; Urochela luteovaria Distant, Urostylididae), Trissolcus elasmuchae (Watanabe) (host: Niphe elongata (Dallas), Pentatomidae), Trissolcus japonicus (Ashmead) (hosts: Erthesina fullo (Thunberg), Pentatomidae; Rhaphigaster nebulosa (Poda), Pentatomidae), Trissolcus latisulcus (Crawford) (host: Poecilocoris latus Dallas, Scutelleridae), Trissolcus mitsukurii (Ashmead) (host: Pentatomidae), Trissolcus semistriatus (Nees von Esenbeck) (host: Eurydema sp., Scutelleridae), Trissolcus yamagishii Ryu (host: Niphe elongata (Dallas), Pentatomidae).
Project description:Dinorhynchus dybowskyi (Hemiptera: Pentatomidae: Asopinae) is used as a biological control agent against various insect pests for its predatory. In the present study, the complete mitochondrial genome (mitogenome) of the species was sequenced using the next-generation sequencing technology. The results showed that the mitogenome is 15,952 bp long, including 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), two ribosomal RNAs (rRNAs), and a control region. Furthermore, the gene order and orientation of this mitogenome are identical to those of most heteropterans. There are 21 intergenic spacers (of length 1-28 bp) and 13 overlapping regions (of length 1-23 bp) throughout the genome. The control region is 1,291 bp long. The start codon of the PCGs is ATN, except cox1 (TTG), and stop codon is TAA, except nad1 (TAG). The 22 tRNAs exhibit a typical cloverleaf secondary structure, except trnS1, which lacks a dihydrouridine (DHU) arm and trnV, where the DHU arm forms a simple loop. The analyses based on nucleotide sequences of the 13 PCGs by Bayesian Inference and maximum likelihood methods. The results support the monophyly of five superfamilies Aradoidea, Pentatomoidea, Pyrrhocoroidea, Lygaeoidea, and Coreoidea. Within Pentatomoidea, the relationship observed is as follows: (Plataspidae + Urostylididae) + (Pentatomidae + (Acanthosomatidae + (Cydnidae + (Scutelleridae + (Dinidoridae + Tessaratomidae))))), and D. dybowskyi was placed in Pentatomidae and close to Eurydema gebleri.
Project description:In this study we focus on the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), which has a strong dispersal capacity and has had a significant impact on several cropping systems, including peach (Prunus persica (L.)). Management of H. halys has relied on intensive insecticide use, and thus a better understanding of its dispersal behavior may assist in developing improved management strategies. In order to investigate H. halys movement and distribution patterns within a peach orchard we applied ecologically safe, food protein markers to the trees along the orchard border (chicken egg albumin in the form of liquid egg whites) and to the trees within the orchard interior (bovine casein in the form of cow's milk). We used enzyme-linked immunosorbent assays (ELISA) to assess whether collected H. halys were "marked" with either of the two protein markers, revealing where in the orchard the bugs had visited. From the density data we determined that H. halys is a perimeter-driven pest in peaches, with a significantly higher density of bugs collected along the orchard border. Interestingly, this trend is primarily driven by the distribution of male bugs. The protein marking data revealed that a small proportion of male H. halys move equally between the orchard border and interior, while a small proportion of females move predominately to the border after visiting the interior. The verification of a strong edge-effect, although potentially sex-specific, implies that H. halys displays a dispersal behavior that may also be exploited for management, which may help growers more efficiently and more effectively manage H. halys.
Project description:Halyomorpha halys (Stål) (Heteroptera: Pentatomidae), the brown marmorated stink bug, is an invasive agricultural and nuisance pest rapidly expanding its incidence in North America. This voracious pest poses a significant threat to rural and urban agriculture, especially to specialty crops such as apples, grapes and ornamentals, as well as staple crops including soybean and corn. The object of this study was to generate transcript sequence resources for H. halys. RNA-seq libraries derived from distinct developmental stages and sexes were sequenced and assembled into 248,569 putatively unique transcripts (PUTs). PUTs were segmented into three disjoint tiers of varying reliability, with 4,794 classified as gold tier (highest quality), 16,878 as silver, and 14,357 as bronze. The gold-tier PUTs associated with 2,580 distinct non-redundant protein sequences from the NCBI NR database--1,785 of these (69%) mapped to annotated UniProtKB database proteins, from which 1,273 unique Pfam families and 459 unique Molecular Function GO terms were encountered. Of the silver tier's 6,527 PUTs associated with unique proteins, 4,193 mapped to UniProtKB (64%), from which 1,941 and 640 unique Pfam and Molecular Function GO terms were extracted. H. halys PUTs related to important life processes like immunity, endocrinology, reproduction, development, behavior, neurotransmission, neurotoxicity, olfaction, and small RNA pathways were validated through quantitative Real-Time PCR (qRT-PCR) for differential expression during distinct life stages (eggs, 2nd instar nymphs, 4th instar nymphs, female adults, male adults). PUTs similar to hypothetical proteins identified in symbiont microbes, including Pantoea and Nosema species, were more abundantly expressed in adults versus nymphs. These comprehensive H. halys transcriptomic resources can be utilized to aid development of novel control methodologies to disrupt life processes; to conduct reverse genetic screens to determine host gene function; and to design environmentally unobtrusive means to control host populations or target specific H. halys life stages, such as molecular biopesticides.
Project description:The family Pentatomidae, the largest within the superfamily Pentatomoidae, comprises about 5,000 species; many of which are economically important pests. Although the phylogeny of Pentatomidae species has been studied using various molecular markers, their phylogenetic relationships remain controversial. Recently, mitochondrial genomes (mitogenomes) have been extensively employed to examine the phylogenetics and evolution of different insects, and in this study, we sequenced complete/near-complete mitochondrial genomes from five shield bug species of Eurydema to gain a better understanding of phylogenetic relationships in the Pentatomidae. The five mitogenomes ranged in length from 15,500 to 16,752 bp and comprised 13 protein-coding genes (PCGs), 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), and a control region. We compared mitogenomic characteristics of the Pentatomidae and constructed phylogenetic trees using Bayesian inference and maximum likelihood methods. Our results showed that gene arrangements, base composition, start/stop codons, gene overlaps, and RNA structures were conserved within the Pentatomidae and that congeneric species shared more characteristics. Saturation and heterogeneity analyses revealed that our PCGs and PCGRNA datasets were valid for phylogenetic analysis. Phylogenetic analyses showed consistent topologies based on BI and ML methods. These analyses strongly supported that Eurydema species belong to the tribe Strachiini, and formed a sister group with Pentatomini. The relationships among Eurydema species were shown to be consistent with their morphological features. (Strachiini + Pentatomini) was found to be a stable sibling of the clade comprising Cappaeini, Graphosomini, and Carpocorini. Furthermore, our results indicated that Graphosoma rubrolineatum (Heteroptera: Pentatomidae) belongs to the Pentatominae and not the Podopinae.
Project description:Native and invasive stink bugs (Hemiptera: Pentatomidae) and the closely related invasive Megacopta cribraria (Hemiptera: Plataspidae) are agricultural pests in the southeastern United States. Natural enemies, from various phyla, parasitize these pests and contribute to population regulation. We specifically investigated Nematoda infections in pentatomid and plataspid pests in one soybean field in South Carolina in 2015. Nematodes were identified through molecular and morphological methods and assigned to family Mermithidae, genus Agamermis. This study reports mermithid nematode infection in immature M. cribraria for the first time and provides the first mermithid host record for the stink bugs Chinavia hilaris, Euschistus servus, and another Euschistus species, and a grasshopper (Orthoptera: Acrididae) in South Carolina. The same Agamermis species infected all hosts. The broad host range and prevalence suggests that Agamermis may be an important contributor to natural mortality of pentatomid and plataspid pests. Previous mermithid host records for the Pentatomidae and Plataspidae worldwide are summarized. Further work is needed to assess the impact of infection on populations over a broader range of agricultural fields and geographic localities.
Project description:The highly polyphagous and invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), has become a significant insect pest in North America since its detection in 1996. It was first documented in northern Utah in 2012 and reports of urban nuisance problems and plant damage have since increased. Biological control is the preferred solution to managing H. halys in North America and other invaded regions due to its alignment with integrated pest management and sustainable practices. Native and non-native biological control agents, namely parasitoid wasps, have been assessed for efficacy. Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae) is an effective egg parasitoid of H. halys in its native range of southeast Asia and has recently been documented parasitising H. halys eggs in North America and Europe. Field surveys for native and exotic egg parasitoids using wild (in situ) and lab-reared H. halys egg masses were conducted in suburban and agricultural sites in northern Utah from June to September 2017-2019. Seven native wasp species in the families Eupelmidae and Scelionidae were discovered guarding H. halys eggs and adult wasps from five of these species completed emergence. Native species had low mean rates of adult emergence from wild (0.5-3.7%) and lab-reared (0-0.4%) egg masses. In 2019, an adventive population of T. japonicus was discovered for the first time in Utah, emerging from 21 of the 106 wild H. halys egg masses found that year, and none from lab-reared eggs. All T. japonicus emerged from egg masses collected on Catalpa speciosa (Warder). Our results support other studies that have observed biological control of H. halys from T. japonicus and improved parasitoid wasp detection with wild as compared to lab-reared H. halys egg masses.
Project description:The genus Rhyncholepta Bergroth, 1911 (Hemiptera: Heteroptera: Pentatomidae: Pentatominae: Chlorocorini) is redescribed and five species-group taxa are recognized, keyed, their diagnostic characters illustrated, and the distribution reviewed. Among the five taxa, two species and one subspecies are recognized as new: Rhyncholeptagrandicallosagrandicallosa Bergroth, 1911 (Brazil, Ecuador, French Guiana, Guyana, Peru, Suriname), Rhyncholeptagrandicallosacentroamericana subsp. n. (Belize, Costa Rica, Guatemala, Mexico, Panama), Rhyncholeptahenryi sp. n. (French Guiana), Rhyncholeptameinanderi Becker & Grazia-Vieira, 1971 (Bolivia, Brazil, Ecuador, Peru), and Rhyncholeptawheeleri sp. n. (Guyana). The structure of the male genital capsule was found to be the only reliable character for identifying species-group taxa. For this reason, a simultaneous application has been submitted to the International Commission on Zoological Nomenclature to set aside the non-informative female lectotype of Rhyncholeptagrandicallosagrandicallosa and replace it with the male neotype suggested herein. Based on the available label data and our field experience, most of the specimens were collected by various types of light traps in or near dense forests. Adults can be collected throughout the year.