Heteropteran Species Research Articles

The ootheca of Libyaspis flavosparsa (Montandon) (Heteroptera: Plataspidae), with a review of ootheca-production in Heteroptera and other Insecta

Parental care behaviours including the defence of oviposited eggs are common strategies to increase the fitness of offspring in animals. Among insects, Hemiptera, the true bugs (Heteroptera) and allies, show a wide range of such strategies. Females of some heteropteran species in the family Plataspidae, in addition to standard maternal care of eggs and early instar nymphs, provide protection of eggs by forming an ootheca, a complex structure coating the egg batch. Although not homologous across the insect taxa in which oothecae occur, structures referred to as oothecae are relatively common in insects, but the literature has so far not been summarized comprehensively. The goals of the present study are twofold. First, we provide a detailed description of the egg and ootheca of the tropical plataspid species Libyaspis flavosparsa (Montandon). The oothecal material of Plataspidae originates from a modified epithelium of the midgut thus represents a unique situation within all insects. Second, the known occurrences of oothecae in Insecta are summarized and discussed. This study provides a basis for future investigations both into the ootheca in Heteroptera and in other insects.

Juvenile hormone identification in the cabbage bug Eurydema rugosa

Juvenile hormone (JH) plays a pivotal role in almost every aspect of insect development and reproduction. The chemical structure of the JH in heteropteran species has long remained elusive until methyl (2R,3S,10R)-2,3;10,11-bisepoxyfarnesoate, commonly named as juvenile hormone III skipped bisepoxide (JHSB3), was isolated from Plautia stali (Hemiptera: Heteroptera: Pentatomidae). Recently, several groups reported the presence of JHSB3 in other heteropteran species. However, most of the studies paid no attention to the determination of the relative and absolute structure of the JH. In this study, we investigated the JH of the cabbage bug Eurydema rugosa (Hemiptera: Heteroptera: Pentatomidae), known as a pest for wild and cultivated crucifers. JHSB3 was detected in the hexane extract from the corpus allatum (CA) product using a chiral ultraperformance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) which can inform the absolute stereochemistry of the JH. Its stereoisomers were not detected. Topical application of the synthetic JHSB3 to the last instar nymphs inhibited their metamorphosis and induced nymphal-type colouration of the dorsal abdomen in a dose-dependent manner. Additionally, the topical application of JHSB3 effectively terminated summer and winter diapauses in females. These results indicate that the JH of E. rugosa is JHSB3. Although individuals in summer and winter diapauses are physiologically distinct in E. rugosa, the results suggest that the physiological differences between these diapauses are based, not on the responsiveness to JH, but on the processes governing activation of the CA or on its upstream cascades.

Effect of Male Body Size on Female Reproduction in Pyrrhocoris apterus (L.) (Heteroptera, Pyrrhocoridae).

Simple SummaryThe benefits of copulation with large males were investigated in the firebug, Pyrrhocoris apterus (L.) (Heteroptera). Sexually immature adults were transferred from the field and kept as female-male pairs with different partner size ratios. We investigated the influence of male body size on the number and weight of eggs and time elapsed from the transfer to their deposition. The expected positive effect of increasing male body size on the characteristics of female reproduction was not detected.Females and males of the abundant heteropteran species Pyrrhocoris apterus (L.) mate with the larger of the available partners. The male benefits from copulation with a large female, which is more productive than a small female. However, the benefit to females from copulation with a large male has not yet been investigated. Overwintered sexually immature adults were transferred from the field to indoors for a long day at 25 °C and subsequently kept as female-male pairs with different partner size ratios. The female lays eggs in several successive clutches. We investigated the influence of male size on the number and weight of eggs in individual clutches and the time elapsed from the transfer to their deposition. These characteristics of reproduction were first regressed on female size, and residuals of this regression were then regressed on male size. The positive effect of increasing male size on the characteristics of female reproduction manifested as a significant value of the latter regressions. The expected positive effect of increasing male body size on female reproductive characteristics was not detected. Several reasons for this deficiency are discussed.

Impact of Black Summer 2019/20 Wildfires on True Bug Priority Species (Insecta: Hemiptera: Heteroptera) in the Northeast Forests of New South Wales

ABSTRACT This study examined the impact of the Black Summer 2019/20 wildfires in the Northeast Forests of New South Wales for seven priority heteropteran (= true bug) species, across a range of vegetation classes and host plants. Our area of study spanned 104,000 km2, from the Queensland border to the Hunter Valley, and west towards Narrabri. We used data primarily from the Plant Bug Inventory database, inclusive of all phytophagous families of the suborder Heteroptera. We identified 122 survey sites based on their distribution in historical collection data and that of their known host plants. These sites were parsed into unburnt (69 locations) and burnt (53 locations), with the latter further categorised by fire severity. The 122 sites were surveyed in four field trips in the late summer early autumn and spring of 2021. One or more of the priority species were detected at thirty-three sites (22 unburnt and 11 burnt sites). The first three field trips (January–March) resulted in the discovery of only Woodwardiola ‘n.sp_LOMA’. The fourth field trip (November) resulted in the discovery of four additional species (Kirkaldyella rugosa, Setocoris ‘n.sp_BINA’, Epimixia vulturna and Eritingis trivirgata), as well as W. ‘n.sp_LOMA’. The two other priority species (Kirkaldyella schuhi and Myrmecoroides grossi) were not found. IUCN Red list methodology was employed to analyse the conservation status of the seven priority species. All seven priority species were found to be species of Least Concern for EEO and Data Deficient for AOO. The Data Deficient categorisation was decided based on insufficient sampling data plus expert opinion. Further sampling is required for all species but is critical for Kirkaldyella schuhi and Myrmecoroides grossi to determine whether their non-detection in this survey is due to sampling inadequacy or due to environmental factors.

Development, Predation, and Prey Preference of Chrysoperla externa on Liorhyssus hyalinus and Nysius simulans, Two Emerging Pests of Quinoa.

In recent years, Liorhyssus hyalinus (Fabricius) (Hemiptera: Rhopalidae) and Nysius simulans Stål (Hemiptera: Lygaeidae) have emerged as important pests of quinoa in Peru, when the crop started to be cultivated at relatively low elevations. The potential of the native lacewing Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) was evaluated as a biological control agent of these two pest species. Prey consumption on all immature stages of L. hyalinus and N. simulans was assessed, as well as development on first instars of these heteropterans and eggs of Sitotroga cerealella (Olivier) (Lepidoptera: Pyralidae) as a factitious prey. In addition, prey preference was examined in the absence and presence of a preferred prey, Macrosiphum euphorbiae (Thomas) (Hemiptera: Aphididae). Larvae of the predator were not able to feed on L. hyalinus eggs, but they effectively did on N. simulans eggs as well as on all nymphal instars of both species. Nymphs of L. hyalinus were less suitable prey for larval development of C. externa than eggs of S. cerealella, whereas N. simulans was overall an unsuitable prey. There was a clear prey preference of C. externa for aphids over the two heteropteran species, as well as a preference for N. simulans over L. hyalinus. The predation rates in this study indicate the potential of C. externa as a predator of these heteropteran pests that can play a role in both conservation and augmentation biological control programs.

Histone H3 Methylation and Autosomal vs. Sex Chromosome Segregation During Male Meiosis in Heteroptera

Heteropteran insects exhibit a remarkable diversity of meiotic processes, including coexistence of different chromosomes types with different behavior during the first meiotic division, non-chiasmatic segregation, and inverted meiosis. Because of this diversity they represent suitable models to study fundamental questions about the mechanisms of chromosome behavior during cell division. All heteropteran species possess holokinetic chromosomes and in most of them the autosomal chromosomes synapse, recombine, and undergoe pre-reductional meiosis. In contrast, the sex chromosomes are achiasmatic, behave as univalents at metaphase I and present an inverted or post-reductional meiosis. An exception to this typical behavior is found in Pachylis argentinus, where both the autosomes and the X-chromosome divide reductionally at anaphase I and then divide equationally at anaphase II. In the present report, we analyzed the distribution of histones H3K9me2 and H3K9me3 in P. argentinus and in five species that have simple and multiple sex chromosome systems with typical chromosome segregation, Belostoma elegans, B. oxyurum, Holhymenia rubiginosa, Phthia picta, and Oncopeltus unifasciatellus. We found that H3K9me3 is a marker for sex-chromosomes from early prophase I to the end of the first division in all the species. H3K9me2 also marks the sex chromosomes since early prophase but shows different dynamics at metaphase I depending on the sex-chromosome segregation: it is lost in species with equationally dividing sex chromosomes but remains on one end of the X chromosome of P. argentinus, where chromatids migrate together at anaphase I. It is proposed that the loss of H3K9me2 from the sex chromosomes observed at metaphase I may be part of a set of epigenetic signals that lead to the reductional or equational division of autosomes and sex chromosomes observed in most Heteroptera. The present observations suggest that the histone modifications analyzed here evolved in Heteroptera as markers for asynaptic and achiasmatic sex chromosomes during meiosis to allow the distinction from the chiasmatic autosomal chromosomes.

Comparative analyses of the venom components in the salivary gland transcriptomes and saliva proteomes of some heteropteran insects.

Salivary gland-specific transcriptomes of nine heteropteran insects with distinct feeding strategies (predaceous, hematophagous, and phytophagous) were analyzed and annotated to compare and identify the venom components as well as their expression profiles. The transcriptional abundance of venom genes was verified via quantitative real-time PCR. Hierarchical clustering of 30 representative differentially expressed venom genes from the nine heteropteran species revealed unique groups of salivary gland-specific genes depending on their feeding strategy. The commonly transcribed genes included a paralytic neurotoxin (arginine kinase), digestive enzymes (cathepsin and serine protease), an anti-inflammatory protein (cystatin), hexamerin, and an odorant binding protein. Both predaceous and hematophagous (bed bug) heteropteran species showed relatively higher transcription levels of genes encoding proteins involved in proteolysis and cytolysis, whereas phytophagous heteropterans exhibited little or no expression of these genes, but had a high expression of vitellogenin, a multifunctional allergen. Saliva proteomes from four representative species were also analyzed. All venom proteins identified via saliva proteome analysis were annotated using salivary gland transcriptome data. The proteomic expression profiles of venom proteins were in good agreement with the salivary gland-specific transcriptomic profiles. Our results indicate that profiling of the salivary gland transcriptome provides important information on the composition and evolutionary features of venoms depending on their feeding strategy.

Five Mitochondrial Genomes of the Genus Eysarcoris Hahn, 1834 with Phylogenetic Implications for the Pentatominae (Hemiptera: Pentatomidae).

Simple SummaryPentatominae is the largest subfamily in the Pentatomidae, and most of its species are considered important agricultural pests. The phylogenetic relationships of tribes within Pentatominae remain controversial despite the fact that many studies have been performed using various molecular markers. In this study, five mitogenomes of the genus Eysarcoris were sequenced and analyzed, and the phylogenetic relationships of tribes within Pentatominae were reconstructed. The gene arrangement of the five mitochondrial genomes were found to be conserved and identical to other heteropteran mitogenomes. Differences in start codon usage and tandem repeats within control regions were found between E. gibbosus and the other four Eysarcoris species. In addition, the phylogenetic analyses showed that E. gibbosus is the first diverging clade within Eysarcorini. The results support the proposal to transfer E. gibbosus to the Stagonomus, another genus of Eysarcorini. Our results clarified the phylogenetic relationships among tribes of Pentatominae and laid a foundation for the further studies of Pentatominae.Four complete mitogenomes of Eysarcoris rosaceus, E. montivagus, E. gibbosus, E. annamita and one near-complete mitochondrial genome of E. ventralis were sequenced and used to explore the phylogenetic relationships of tribes within the subfamily Pentatominae. The mitogenomes range from 15,422 to 16,043 base pairs (bp) in length and encode 37 genes, including 13 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes (21 in E. ventralis), and a control region. Similar to other heteropteran species, the AT contents of the sequenced species were higher than their GC contents. The most frequently used start/stop codon was ATN/TAA. GTG was only found in atp6 and atp8 of E. gibbosus. All transfer RNA genes (tRNAs) exhibit the typical cloverleaf secondary structure, except for the trnS1 and trnV, which lacks the stem of the DHU arm. The length and copy number of repeat units were conserved within Eysarcoris, with the exception of E. gibbosus. Phylogenetic analyses based on mitogenomes using both maximum likelihood (ML) and Bayesian inference (BI) methods strongly supported the relationship among tribes within Pentatominae and confirmed that Graphosoma should be an intermediate lineage of Pentatominae. The relationship between Eysarcoris and Carbula was strongly supported and combined with our previous geometric morphometrics and chromosomal studies, suggest the Eysarcoris should belong to the tribe Eyasrcorini. This work will help to enhance our understanding of mitochondrial genomic evolution and phylogenetic relationships in Pentatominae.

The Relationship between Proboscis Length and the Ability of Certain Heteroptera to Damage Macadamia Kernels

The gradual increase in kernel (nut) size as the macadamia seed develops, appears to play a role in the decline of kernel susceptibility to feeding by insects of the suborder Heteroptera. In some cultivars the kernel becomes resistant to feeding before others due to differences in husk and shell thickness (e.g. feeding by Nezara spp.), but species with a long proboscis (e.g. Bathycoelia spp.) could still feed on the kernel after maximum fruit size was reached. The thickness of the husk and shell, and not the hardness of the shell, was the limiting factor in kernel feeding. Bathycoelia distincta Distant (Pentatomidae) and Pseudotheraptus wayi Brown (Coreidae) were the most damaging heteropteran species with respect to the size of the kernel lesions caused. A single feeding incident during early fruit development could cause large necrotic lesions, which totally malformed the kernel. Farnya sp. and Nezara sp. caused only small shallow lesions. During the fruit maturation period, only B. distincta was able to damage the kernel significantly due to its long proboscis. The extent of fruit damage was dependent on the stage of fruit development and the species concerned. A tolerance index was developed to express the relative tolerance of macadamia cultivars to the damage caused by kernel-feeding Pentatomidae at the later stages of fruit development. Parameters for the index were the number of pentatomids attacking macadamia, their proboscis length and the combined thickness of the husk and shell of the fruit.

Juvenile hormone III skipped bisepoxide is widespread in true bugs (Hemiptera: Heteroptera).

Juvenile hormone (JH) plays important roles in almost every aspect of insect development and reproduction. JHs are a group of acyclic sesquiterpenoids, and their farnesol backbone has been chemically modified to generate a homologous series of hormones in some insect lineages. JH III (methyl farnesoate, 10,11-epoxide) is the most common JH in insects, but Lepidoptera (butterflies and moths) and ‘higher’ Diptera (suborder: Brachycera; flies) have developed their own unique JHs. Although JH was first proposed in the hemipteran suborder Heteroptera (true bugs), the chemical identity of the heteropteran JH was only recently determined. Furthermore, recent studies revealed the presence of a novel JH, JH III skipped bisepoxide (JHSB3), in some heteropterans, but its taxonomic distribution remains largely unknown. In the present study, we investigated JHSB3 production in 31 heteropteran species, covering almost all heteropteran lineages, through ultra-performance liquid chromatography coupled with tandem mass spectrometry. We found that all of the focal species produced JHSB3, indicating that JHSB3 is widespread in heteropteran bugs and the evolutionary occurrence of JHSB3 ascends to the common ancestor of Heteroptera.

Contributions to the knowledge of water bugs in Mindoro Island, Philippines, with a species checklist of Nepomorpha and Gerromorpha (Insecta, Hemiptera, Heteroptera).

BackgroundThis survey aims to provide an updated species checklist of aquatic and semi-aquatic bugs in the intra-Philippine biogeographic Region of Mindoro. An assessment survey of water bugs (Hemiptera, Heteroptera) was conducted mostly by manual collection in selected areas of Oriental Mindoro from 2017 to 2018, in which some of the collecting activities were undertaken by graduate students of Ateneo de Manila University.New informationTwenty-nine aquatic and semi-aquatic heteropteran species were documented and some are known island-endemic species or subspecies, including Enithares martini mindoroensis Nieser & Zettel, 1999, Hydrotrephes stereoides mindoroensis Zettel, 2003, Aphelocheirus freitagi Zettel & Pangantihon, 2010, Rhagovelia mindoroensis Zettel, 1994, Rhagovelia raddai Zettel, 1994, Rhagovelia potamophila Zettel, 1996 and Strongylovelia mindoroensis Lansbury & Zettel, 1997, which were found in new areas in the Region. In addition, there are also new records for the Island that have already been documented in other parts of the Philippines, such as the Philippine-endemic Ochterus magnus Gapud & San Valentin, 1977 and Hebrus philippinus Zettel, 2006 and the widely-distributed backswimmers Anisops nigrolineatus Lundblad, 1933 and Anisops rhomboides Nieser & Chen, 1999. Several undescribed specimens and potentially new species are also discussed in this paper. Further surveys in the other parts of Mindoro and in the other regions of the Philippines, are encouraged to produce a comprehensive baseline data of heteropteran species richness in the country.

Indirect effects of weeds on rice plants via shared heteropteran herbivores

AbstractIn agricultural ecosystems, weeds indirectly affect crops via phytophagous insects that feed on both weeds and crops. In paddy fields, heteropteran insects are among the most serious pests of rice plants. In some heteropterans, the proboscis is used to suck rice ears, inducing black spots on the grains (i.e., pecky rice). Even a low proportion of pecky rice (>0.1%) significantly decreases the market price of rice; in Japan, this problem has led to severe economic losses. Because heteropterans feed on the reproductive organs of weeds as well as rice plants, various weeds that grow around paddy fields may increase the populations of heteropterans that cause pecky rice. To clarify which types of weeds can be used by heteropterans causing pecky rice, we investigated the interactions between plants (including rice plants) and heteropterans in an agricultural landscape in Hyogo, Japan. We observed 833 individuals of 27 heteropteran species (13 families) feeding on the reproductive organs of 35 plant species (Poales: three families) including rice plants from June to October 2019. All heteropteran species were native, whereas six of 35 plant species were non‐native. We found 12 heteropteran species on rice plants; nine of the 12 heteropteran species fed on weeds (a total of 32 species) as well as rice plants, whereas the other three species fed exclusively on rice plants. Heteropterans fed on native weeds throughout the growing seasons (June–October), but on non‐native weeds only before rice plants bloomed (June–July). Therefore, diverse weed species that grow around paddy fields are food resources for heteropteran insects and they might indirectly increase the incidence of pecky rice.

Camphor and Borneol as the Male-Produced Sex Pheromone of the Shield Bug, Orsilochides leucoptera (Hemiptera: Scutelleridae).

The ability of stink bugs to release high amounts of strong-smelling and irritating defensive compounds is related to their metathoracic gland (MTG), which is an exocrine gland with defensive, sexual, alarm and aggregation signal functions. Orsilochides leucoptera (Scutelleridae) is a widespread species in the Neotropical region that feeds on plants of the families Malvaceae, Poaceae and Euphorbiaceae. A series of compounds (ketones, alcohols and esters) have been identified in the MTGs among the three species of Scutelleridae whose MTG secretions have been investigated thus far; however, no sex pheromone compounds have been described for any scutellerid species. The aim of this work was to study sex pheromone communication within this family of stink bugs, and identify the compounds present in the MTG of O. leucoptera. Analysis by gas chromatography/mass spectrometry (GC/MS) revealed two male specific compounds identified as (R)-camphor (1) and (R)-borneol (2), which were attractive to females in Y-tube olfactometer bioassays. Also, GC/MS analysis of secretions from MTG of males and females of O. leucoptera, identified eight additional compounds: 2-(E)-hexenal (3), (E)-4-oxo-2-hexenal (4), (E)-hex-2-enyl acetate (5), (R)-linalool (6), (R)-α-terpineol (7), dodecane (8), 1-tridecene (9) and n-tridecane (10). From these, (R)-α-terpineol was detected only in the gland of males, and is probably a biosynthetic intermediate of the pheromone components. Most of the MTG compounds identified in O. leucoptera have been identified in other heteropteran species. Camphor is often a toxic and repellent compound for insects. However, we report it, for the first time, as a sex pheromone component of an insect.

The juvenile hormone described in Rhodnius prolixus by Wigglesworth is juvenile hormone III skipped bisepoxide

Juvenile hormones (JHs) are sesquiterpenoids synthesized by the corpora allata (CA). They play critical roles during insect development and reproduction. The first JH was described in 1934 as a “metamorphosis inhibitory hormone” in Rhodnius prolixus by Sir Vincent B. Wigglesworth. Remarkably, in spite of the importance of R. prolixus as vectors of Chagas disease and model organisms in insect physiology, the original JH that Wigglesworth described for the kissing-bug R. prolixus remained unidentified. We employed liquid chromatography mass spectrometry to search for the JH homologs present in the hemolymph of fourth instar nymphs of R. prolixus. Wigglesworth’s original JH is the JH III skipped bisepoxide (JHSB3), a homolog identified in other heteropteran species. Changes in the titer of JHSB3 were studied during the 10-day long molting cycle of 4th instar nymph, between a blood meal and the ecdysis to 5th instar. In addition we measured the changes of mRNA levels in the CA for the 13 enzymes of the JH biosynthetic pathway during the molting cycle of 4th instar. Almost 90 years after the first descriptions of the role of JH in insects, this study finally reveals that the specific JH homolog responsible for Wigglesworth’s original observations is JHSB3.

Juvenile hormone III skipped bisepoxide, not its stereoisomers, as a juvenile hormone of the bean bug Riptortus pedestris

Juvenile hormone (JH) plays a pivotal role in many aspects of insect physiology. Although its presence was first reported in a blood-sucking bug belonging to the suborder Heteroptera (true bugs), JH species in the group has long been controversial. Although some recent studies proposed a putative JH molecular species in several Heteropteran species, it is not conclusive because physicochemical analyses were insufficient in most cases. Here, we studied this issue with an ultraperformance liquid chromatography–tandem mass spectrometer (UPLC-MS/MS) equipped with C18 and chiral columns in the bean bug Riptortus pedestris (Heteroptera, Alydidae), in which the JH species has long been controversial. Although a recent study describes JHSB3 as the major JH of this species, that finding was not conclusive because its chirality has not been clarified. In the present study, we detected methyl (2R,3S,10R)-2,3;10,11-bisepoxyfarnesoate, commonly named juvenile hormone III skipped bisepoxide (JHSB3), in the culture media of the corpora cardiaca-corpus allatum (CC-CA) complex and in the hemolymph of this species by a chiral ultraperformance liquid chromatography- tandem mass spectrometer (UPLC-MS/MS). Other JHSB3 stereoisomers were not detected. Topical application of JHSB3 effectively averted diapause. These results indicate that JHSB3 is the major JH of R. pedestris. The present study further revealed that JHSB3 and its (2R,3S,10S) isomer are more potent than (2S,3R,10R) and (2S,3R,10S) isomers, which suggests that there is a significance to the configuration of the 2,3-epoxide moiety in JH action. We further found a supplemental significance to the configuration of the 10-position.

Intercrop movement of heteropteran predators between alfalfa and maize examined by stable isotope analysis

Alfalfa is a reservoir providing natural enemies to adjacent crops. However, whether these crops act only as receptors or also as donors is unknown. The pattern of movement between alfalfa and maize of Orius majusculus, Orius niger and Nabis provencalis and the role of both crops as “donor” or “receptor” were inferred through carbon and nitrogen stable isotope analysis. Results show that all heteropteran species are able to move between crops, but the predators’ movement is species specific and the role of alfalfa and maize as “donor” or “receptor” varies. The movement is also affected by crop management practices such as alfalfa cutting. All heteropterans that colonized maize at its early stage came from alfalfa, but N. provencalis also moved back to alfalfa from maize. Alfalfa cutting triggers movement of heteropterans to maize, but the time when this practice is performed also affects the movement. Alfalfa cutting did not have consequences on the recolonization of alfalfa, and some of the heteropterans found during the alfalfa regrowth period seem to have remained within alfalfa (mainly N. provencalis) while others came from maize (mainly O. majusculus and O. niger). When maize was harvested or dry, O. majusculus moved to alfalfa later than the other two predators. Due to the movement capacity of heteropterans between alfalfa and maize and the variable role of both crops as “donor” or “receptor”, conservation biological control could be enhanced by including adjacent fields of alfalfa and maize or a mosaic of both crops at farm and landscape levels.

Composición y estructura de heterópteros (Hemiptera) en ecosistemas lóticos costeros del Pacífico colombiano.

Aquatic and semiaquatic heteropterans present high richness in the Colombian Pacific Region. Studies about biology, ecology, as well as geographical and altitudinal distribution have provided a great amount of data about some species inhabiting brackish waters, as well as lentic and lotic freshwaters. Based on that, the aim of this study was to compare three communities of aquatic and semiaquatic heteropterans of lotic freshwater ecosystems from the Pacific coastal region in Colombia based on species composition, richness, diversity and abundance. In order to meet this objective, sites were sampled at altitudes ranging from 0 and 35 m of altitude above sea level in the Pacific littoral in Tumaco (Department of Narino): two sites were located in permanent lotic ecosystems in the Mejicano and Caunapi rivers and a third site was located in a slow-flow intermittent stream in Candelillas. The composition, richness, diversity and abundance for each ecosystem, as well as the beta diversity on the basis of the Jaccard similarity coefficient and the value of importance of species for abundance were determined. A total of 339 individuals, seven families and 25 species were recorded. Each ecosystem presented 11 species, with Gerridae the most abundant family in the three ecosystems. Differences between the specific composition, diversity and abundance of the three ecosystems, in terms of genera and species, were determined. The similarity between the three aquatic ecosystems was lower than 20%. The intermittent stream in Candelillas was the aquatic ecosystem with the greatest diversity of heteropterans, according to the index of Shannon-Wiener. In the Mejicano River, Rhagovelia was the genus with a greatest number of species and individuals, and Telmatometra whitei was the most abundant species. In the Caunapi river, Rhagovelia was the genus with the greatest number of species and individuals and Martarega lofoides was the most abundant species. In the intermittent stream in Candelillas, Rheumatobates was the genus with the greatest number of species and individuals, and R. peculiaris was the most abundant species. The species with the highest Importance Value Index was Telmatometra whitei . The three coastal lotic ecosystems presented different compositions of heteropteran species and dissimilar structure over a very narrow altitudinal range.

Neuropeptidomics of the Bed Bug Cimex lectularius.

The bed bug Cimex lectularius is a globally distributed human ectoparasite with fascinating biology. It has recently acquired resistance against a broad range of insecticides, causing a worldwide increase in bed bug infestations. The recent annotation of the bed bug genome revealed a full complement of neuropeptide and neuropeptide receptor genes in this species. With regard to the biology of C. lectularius, neuropeptide signaling is especially interesting because it regulates feeding, diuresis, digestion, as well as reproduction and also provides potential new targets for chemical control. To identify which neuropeptides are translated from the genome-predicted genes, we performed a comprehensive peptidomic analysis of the central nervous system of the bed bug. We identified in total 144 different peptides from 29 precursors, of which at least 67 likely present bioactive mature neuropeptides. C. lectularius corazonin and myosuppressin are unique and deviate considerably from the canonical insect consensus sequences. Several identified neuropeptides likely act as hormones, as evidenced by the occurrence of respective mass signals and immunoreactivity in neurohemal structures. Our data provide the most comprehensive peptidome of a Heteropteran species so far and in comparison suggest that a hematophageous life style does not require qualitative adaptations of the insect peptidome.

Suitability of Two Sampling Methods for Determining the Population Trends of Certain Sap-Sucking Species Inhabiting Tomato and Cucumber Plantations

Faunistic composition and seasonal abundance of certain sap-sucking species inhabiting tomato and cucumber plantations were determined by using sweep net and direct count methods, during summer seasons of 2015 and 2016 in Assiut Governorate, Northern Upper Egypt. Twelve species belonging to 8 families and 3 orders in addition to the acarid mite were recorded. Heteropteran species were found to be constituted 69.24% of the gathered species. However, Homopteran species were found to be constituted 15.38%. Thysanoptera and Tetranichidae were presented by 7.69% for each. Concerning to the sampling method, 76.92% of the collected species were captured by the sweep net method, while 23.08% were gathered by the direct count method. The recovered species were classified as predominantly predaceous, predominantly phytophagous, predaceous in part and phytophagous in part species. Seasonal abundance of the recorded species was determined. The distinct predators, Coranus aegyptius (Fabricius, 1775) and Orius spp. showed relatively low abundance percentages. The predatory-phytophagous mirid species [Campylomma unicolor Poppius, 1914; Nesidiocoris tenuis (Reuter, 1895); Creontiades pallidus (Rambur, 1839). and Deraeocoris serenus (Douglas & Scott, 1868)], showed different abundance percentages. Amongst these taxa, N. tenuis revealed the highest abundance percentage on tomato plantations with an average of 63.00 and 75.00% during 2015 and 2016 seasons, respectively. The distinct phytophagous species, Thrips tabaci Lindeman, 1889; Bemisia tabaci (Gennadius, 1889) and Tetranychus urticae Koch, 1836 presented the greatest abundance percentages on cucumber when estimated by the direct count method.So, this work can be reflect the importance of sweep net as a suitable sampling method for determine the faunistic composition of the flight predatory insects inhabiting tomato and cucumber. However, direct count can be consider the most suitable method for determine the population trends of mobile or non-mobile arthropods inhabiting the same crops. Also, use of more than one sampling method could be successful to clarify the relation between useful and harmful arthropod species.

A karyotype comparison between two species of bordered plant bugs (Hemiptera, Heteroptera, Largidae) by conventional chromosome staining, C-banding and rDNA-FISH.

A cytogenetic characterization, including heterochromatin content, and the analysis of the location of rDNA genes, was performed in Largus fasciatus Blanchard, 1843 and L. rufipennis Laporte, 1832. Mitotic and meiotic analyses revealed the same diploid chromosome number 2n = 12 + X0/XX (male/female). Heterochromatin content, very scarce in both species, revealed C-blocks at both ends of autosomes and X chromosome. The most remarkable cytological feature observed between both species was the different chromosome position of the NORs. This analysis allowed us to use the NORs as a cytological marker because two clusters of rDNA genes are located at one end of one pair of autosomes in L. fasciatus, whereas a single rDNA cluster is located at one terminal region of the X chromosome in L. rufipennis. Taking into account our results and previous data obtained in other heteropteran species, the conventional staining, chromosome bandings, and rDNA-FISH provide important chromosome markers for cytotaxonomy, karyotype evolution, and chromosome structure and organization studies.