Search

Understanding the population genetic structure and demographic dynamics of important agricultural pest insects is very important in studying insecticide resistance and control strategies. The plant bug Adelphocoris fasciaticollis (Reuter) (Hemiptera: Miridae) is one of the main insect pests on cotton in Northern China. We studied large-scale genetic structure and genetic diversity patterns and explored the demographic history. We also employed a phylogeographical approach on A. fasciaticollis samples using sequence data from mitochondrial DNA (mtDNA) and nuclear DNA (ncDNA). MtDNA showed a significant correlation between genetic and geographical distances, but ncDNA did not support this correlation. Both datasets revealed that A. fasciaticollis populations had experienced recent expansion and lacked a geographical structure. One reason for lack of a genetic structure is a high level of gene flow among the populations. We suggest that the strong flight capability of A. fasciaticollis has been aided by the East Asian monsoon and cold fronts to accelerate the rate of range expansion. In addition, decreased insecticide usage and disturbances from human activities may all have contributed to population expansion. The low effective population number was based on two datasets. It is suggested that the host crop use, local climate conditions, and the recent population expansion might be the main influencing factors. [ABSTRACT FROM AUTHOR]

Togepsyllinae is a distinctive group within Psylloidea, with its systematic status treated variously by different authors. Of the only two known genera, Togepsylla is better known and distributed in temperate and tropical East Asia. In this study, the taxonomy and morphology of Togepsylla was studied in detail. Keys to adults and fifth instar immatures of the genus are provided. Togepsylla glutinosae sp. n. is described, and T. matsumurana, T. takahashii, and T. tibatana are redescribed. Syncoptozus is compared with Togepsylla for differences in morphology. Modern psyllids have evolved their jumping hind legs via the elongation of the dorsal edge of coxa, the broadening of coxal wall, the thickening of meron, the backward twisting of the plane of trochanter, femur, and tibia, and the enlargement of trochanteral tendon. However, in Togepsylla, this modification has progressed halfway. The metapleuron of Togepsylla is arranged in a different way than other psyllids. The pleural sulcus is short, and the metepisternum and trochantin are not divided. Wax-secreting fields on abdominal sternites, resembling those of whiteflies, are found on all Togepsylla species, and described for the first time. Other distinctive characters of the genus are also revealed, e.g. frons completely fused with gena, a pair of extra sclerites present behind the base of thoracic furca, one-segmented aedeagus, and absence of a flag lobe on valvula dorsalis of ovipositor. Based on various similarities in morphology, Togepsyllinae may have a close relationship with Aphalaridae-Rhinocolinae and is possibly related to Homotomidae, Liviidae- Liviinae and Atmetocranium (Calophyidae). All the distinctive characters of Togepsyllinae suggest that the current placement of the group is doubtful, and the phylogeny of Aphalaridae needs to be resolved. [ABSTRACT FROM AUTHOR]

Two new species of the thread-legged bug genus Ademula McAtee & Malloch, 1926 (Hemiptera: Reduviidae: Emesinae: Emesini, formerly Ploiariolini) from China, A. callipennis, new species, and A. corniculata, new species, are described and illustrated in the present paper. COI barcodes of these two new species and an updated key to the Oriental species of Ademula are provided. The distribution of Ademula in East and Southeast Asia is briefly discussed. [ABSTRACT FROM AUTHOR]

A new genus of velvety shore bugs, Pristinochterus gen. n., with one new species, Pristinochterus zhangi sp. n., are described. The specimens were collected from the Late Jurassic to Early Cretaceous Yixian Formation and Early Cretaceous Jiufotang Formation in northeastern China. This finding represents the first record of fossil velvety shore bugs from China. Among the specimens, four well-preserved nymphs are reported for the first time. The placement of the new genus within Ochteridae is briefly discussed. A key to the world genera of Ochteridae is provided. [ABSTRACT FROM AUTHOR]

Müllerian mimicry was proposed to be an example of a coevolved mutualism promoted by population isolation in glacial refugia. This, however, has not been well supported in butterfly models. Here, we use genomic data to test this theory while examining the population genetics behind mimetic diversification in a pair of co-mimetic bumble bees, Bombus breviceps Smith and Bombus trifasciatus Smith. In both lineages, populations were structured by geography but not as much by color pattern, suggesting sharing of color alleles across regions of restricted gene flow and formation of mimicry complexes in the absence of genetic differentiation. Demographic analyses showed mismatches between historical effective population size changes and glacial cycles, and niche modeling revealed only mild habitat retraction during glaciation. Moreover, mimetic subpopulations of the same color form in the two lineages only in some cases exhibit similar population history and genetic divergence. Therefore, the current study supports a more complex history in this comimicry than a simple refugium-coevolution model. [ABSTRACT FROM AUTHOR]

The identities of two species of assassin bugs in the tribe Ectinoderini (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from the Indochinese Peninsula are reviewed, resulting in the following new synonymy and new combinations: Amulius Stål, 1865 = Parapanthous Distant, 1919, syn. n.; Amulius spinicollis (Distant, 1919), comb. n. (transferred from Parapanthous) and Ectinoderus confragosus (Distant, 1919), comb. n. (transferred from Amulius). Lectotypes of these species are designated. The hemelytral venations of Amulius and Ectinoderus Westwood, 1843 are briefly discussed and their diagnoses accordingly revised. Amulius is newly reported from Vietnam and Ectinoderus is recorded from Cambodia for the first time. [ABSTRACT FROM AUTHOR]

Background: Metazoan adenosine-to-inosine (A-to-I) RNA editing resembles A-to-G mutation and increases proteomic diversity in a temporal-spatial manner, allowing organisms adapting to changeable environment. The RNA editomes in many major animal clades remain unexplored, hampering the understanding on the evolution and adaptation of this essential post-transcriptional modification. Methods: We assembled the chromosome-level genome of Coridius chinensis belonging to Hemiptera, the fifth largest insect order where RNA editing has not been studied yet. We generated ten head RNA-Seq libraries with DNA-Seq from the matched individuals. Results: We identified thousands of high-confidence RNA editing sites in C. chinensis. Overrepresentation of nonsynonymous editing was observed, but conserved recoding across different orders was very rare. Under cold stress, the global editing efficiency was down-regulated and the general transcriptional processes were shut down. Nevertheless, we found an interesting site with "conserved editing but non-conserved recoding" in potassium channel Shab which was significantly up-regulated in cold, serving as a candidate functional site in response to temperature stress. Conclusions: RNA editing in C. chinensis largely recodes the proteome. The first RNA editome in Hemiptera indicates independent origin of beneficial recoding during insect evolution, which advances our understanding on the evolution, conservation, and adaptation of RNA editing. [ABSTRACT FROM AUTHOR]

Rhodnius Stål, 1859 is the second largest genus of Triatominae after Triatoma Laporte, 1832, and includes several important Chagas vectors. Genitalia in Reduviidae are frequently used for species identification, but the current use of terminology for it is inconsistent in Triatominae. Here, Rhodnius micki sp. nov., is described from Bolivia and considered as belonging to the pictipes group based on its morphological characters and distribution. Detailed documentation of the genitalia of Rhodnius micki sp. nov. is provided with emphasis on its everted phallus, especially the endosomal sclerites, which are potentially useful as species-level diagnostic features in Rhodnius. To further verify the validity of this species, the head shapes and wing venation patterns of five species in Rhodnius are compared with morphometric analysis. After reviewing taxonomic and comparative morphology papers of assassin bugs, a vocabulary with a terminology of morphological characters, especially of external male genitalic characters, is assembled with the preferred terms and the synonyms listed. Establishing a consistent terminological framework will greatly facilitate future research on the homology of these structures across Triatominae and will ultimately contribute to our understanding of the evolution of these groups. [ABSTRACT FROM AUTHOR]

Hornylia obtusipetala sp. nov. from eastern Thailand is described and illustrated. This new species is the second representative of the genus Hornylia Wygodzinsky, 1966. A key to species of Hornylia is presented. The relationship with allied genera and distribution of Hornylia is briefly discussed. Hornylia is recorded from Thailand for the first time. [ABSTRACT FROM AUTHOR]

The Oriental assassin bug genus Enoplocephala Miller, 1940, is revised and redescribed. Two species are recognised: the type species, E. perakensis Miller, 1940, is redescribed and illustrated based on the type specimen; an additional species, E. maculata, new species, is described and illustrated based on one specimen from Borneo. Systematic position, distribution, and habitat of this genus are briefly discussed. [ABSTRACT FROM AUTHOR]

Renicoris gen. nov. and its type species Renicoris robustus sp. nov. (Hemiptera: Heteroptera: Reduviidae: Harpactorinae) from Yunnan, China, are described and illustrated. A key to separate the new genus and its closely related genera is provided. [ABSTRACT FROM AUTHOR]

Re-examination of type specimens of Libiocoris Kormilev 1957, L. poecilus from New Guinea and other taxa assigned to this genus, the Chinese Libiocoris heissi Bai, Yang & Cai, 2006 and Libiocoris sinensis Bai, Yang & Cai, 2006 proved to be synonyms, thus L. heissi = L. sinensis syn. n. They are, however, different from Libiocoris Kormilev, 1957 to which they were originally assigned and a new genus Paralibiocoris gen. n. is proposed for them. Therefore Paralibiocoris heissi comb. n. = Libiocoris heissi Bai et al., 2006 = Libiocoris sinensis Bai et al., 2006, syn. n. From Hainan Island, China, the following new species, P. roundangulus sp. n., P. hainanensis sp. n., and P. limuensis sp. n., are described and figured and a key to species is provided. [ABSTRACT FROM AUTHOR]

The following new apterous fl at bugs of the subfamily Carventinae (Hemiptera: Heteroptera: Aradidae) from China are described and illustrated: Cathaycoris bibulbosus gen. nov. & sp. nov. from Yunnan Province; Taiwanaptera guangxiana sp. nov. from Guangxi Province and Taiwanaptera montana sp. nov. from Yunnan Province. A key to all known species of Taiwanaptera is provided. [ABSTRACT FROM AUTHOR]

The following new apterous flat bugs of the subfamily Carventinae (Hemiptera: Heteroptera: Aradidae) from China are described and illustrated: Cathaycoris bibulbosus gen. nov. & sp. nov. from Yunnan Province; Taiwanaptera guangxiana sp. nov. from Guangxi Province and Taiwanaptera montana sp. nov. from Yunnan Province. A key to all known species of Taiwanaptera is provided. [ABSTRACT FROM AUTHOR]

The African assassin bug genus Neopirates Miller, 1952, is revised. The type species, N. nyassae Miller, 1952, is redescribed and illustrated; two new species from Namibia, N. bicolor Liu & Cai sp. n. and N. xanthothorax Liu & Cai sp. n. are described and a key is provided to separate the three species of this genus. Sphodrembas fumipennis Swanson, 2019, the type species of Sphodrembas Swanson, 2019, is placed as a junior synonym of N. nyassae, resulting in Sphodrembas becoming a junior synonym of Neopirates. Morphological differences between Neopirates and similar genera and the distribution of Neopirates are briefly discussed. [ABSTRACT FROM AUTHOR]

Chenicoris dilatatus gen. n. & sp. n. from southern China is described and placed in the largest assassin bug subfa mily Harpactorinae (Hemiptera: Heteroptera: Reduviidae). The new species is similar to members of Isyndus Stål, 1859 in general habitus, but can be distinguished from the latter by the unarmed anterior pronotal lobe, the laterally dilated lobe-like abdominal segment V and several features of its genitalia. [ABSTRACT FROM AUTHOR]

The family Pachynomidae is recorded from Borneo as well as Southeast Asia for the first time. Camarochiloides gen. n. and its type species C. weiweii sp. n. is described. Dorsal habitus and various morphological characters of the new species are illustrated. Subfamily placement and affinities of the new genus are briefly discussed, a key to the genera of Pachynominae is provided. Body and wing polymorphism and nymphal morphology of the new species are documented. [ABSTRACT FROM AUTHOR]

The booklouse, Liposcelis bostrychophila is an important storage pest worldwide. The mitochondrial (mt) genome of an asexual strain (Beibei, China) of the L. bostrychophila comprises two chromosomes; each chromosome contains approximate half of the 37 genes typically found in bilateral animals. The mt genomes of two sexual strains of L. bostrychophila, however, comprise five and seven chromosomes, respectively; each chromosome contains one to six genes. To understand mt genome evolution in L. bostrychophila, and whether L. bostrychophila is a cryptic species, we sequenced the mt genomes of six strains of asexual L. bostrychophila collected from different locations in China, Croatia, and the United States. The mt genomes of all six asexual strains of L. bostrychophila have two chromosomes. Phylogenetic analysis of mt genome sequences divided nine strains of L. bostrychophila into four groups. Each group has a distinct mt genome organization and substantial sequence divergence (48.7-87.4%) from other groups. Furthermore, the seven asexual strains of L. bostrychophila, including the published Beibei strain, are more closely related to two other species of booklice, L. paeta and L. sculptilimacula, than to the sexual strains of L. bostrychophila. Our results revealed highly divergent mt genomes in the booklouse, L. bostrychophila, and indicate that L. bostrychophila is a cryptic species. [ABSTRACT FROM AUTHOR]

Hemiptera, the largest non-holometabolous order of insects, represents approximately 7% of metazoan diversity. With extraordinary life histories and highly specialized morphological adaptations, hemipterans have exploited diverse habitats and food sources through approximately 300 Myr of evolution. To elucidate the phylogeny and evolutionary history of Hemiptera, we carried out the most comprehensive mitogenomics analysis on the richest taxon sampling to date covering all the suborders and infraorders, including 34 newly sequenced and 94 published mitogenomes. With optimized branch length and sequence heterogeneity, Bayesian analyses using a site-heterogeneous mixture model resolved the higher-level hemipteran phylogeny as (Sternorrhyncha, (Auchenorrhyncha, (Coleorrhyncha, Heteroptera))). Ancestral character state reconstruction and divergence time estimation suggest that the success of true bugs (Heteroptera) is probably due to angiosperm coevolution, but key adaptive innovations (e.g. prognathous mouthpart, predatory behaviour, and haemelytron) facilitated multiple independent shifts among diverse feeding habits and multiple independent colonizations of aquatic habitats. [ABSTRACT FROM AUTHOR]

A strain of the Asian corn borer (ACB), Ostrinia furnacalis (Guenée), has evolved >800-fold resistance to Cry1Ie (ACB-IeR) after 49 generations of selection. The inheritance pattern of resistance to Cry1Ie in ACB-IeR strain and its cross-resistance to other Bt toxins were determined through bioassay by exposing neonates from genetic-crosses to toxins incorporated into the diet. The response of progenies from reciprocal F1 crosses were similar(LC50s: 76.07 vs. 74.32 μg/g), which suggested the resistance was autosomal. The effective dominance (h) decreased as concentration of Cry1Ie increased. h was nearly recessive or incompletely recessive on Cry1Ie maize leaf tissue (h = 0.02), but nearly dominant or incompletely dominant (h = 0.98) on Cry1Ie maize silk. Bioassay of the backcross suggested that the resistance was controlled by more than one locus. In addition, the resistant strain did not perform cross-resistance to Cry1Ab (0.8-fold), Cry1Ac (0.8-fold), Cry1F (0.9-fold), and Cry1Ah (1.0-fold). The present study not only offers the manifestation for resistance management, but also recommends that Cry1Ie will be an appropriate candidate for expression with Cry1Ab, Cry1Ac, Cry1F, or Cry1Ah for the development of Bt maize. [ABSTRACT FROM AUTHOR]

Most assassin bugs are predators that act as important natural enemies of insect pests. Mitochondrial (mt) genomes of these insects are double-strand circular DNAs that encode 37 genes. In the present study, we explore the duplication and rearrangement of tRNA genes in the mt genome of Reduvius tenebrosus, the first mt genome from the subfamily Reduviinae. The gene order rearranges from CR (control region)-trnI-trnQ-trnM-ND2 to CR-trnQ-trnI2-trnI1-trnM-ND2. We identified 23 tRNA genes, including 22 tRNAs commonly found in insects and an additional trnI (trnI2), which has high sequence similarity to trnM. We found several pseudo genes, such as pseudo-trnI, pseudo-CR, and pseudo-ND2, in the hotspot region of gene rearrangement (between the control region and ND2). These features provided evidence that this novel gene order could be explained by the tandem duplication/random loss (TDRL) model. The tRNA duplication/anticodon mutation mechanism further explains the presence of trnI2, which is remolded from a duplicated trnM in the TDRL process (through an anticodon mutation of CAT to GAT). Our study also raises new questions as to whether the two events proceed simultaneously and if the remolded tRNA gene is fully functional. Significantly, the duplicated tRNA gene in the mitochondrial genome has evolved independently at least two times within assassin bugs. [ABSTRACT FROM AUTHOR]

After decades of debate, a mostly satisfactory resolution of relationships among the 11 recognized holometabolan orders of insects has been reached based on nucleargenes, resolving one of the most substantial branches of the tree-of-life, but the relationships are still not well established with mitochondrial genome data. The main reasons have been the absence of sufficient data in several orders and lack of appropriate phylogenetic methods that avoid the systematic errors from compositional and mutational biases in insect mitochondrial genomes. In this study, we assembled the richest taxon sampling of Holometabola to date (199 species in 11 orders), and analyzed both nucleotide and amino acid data sets using several methods. We find the standard Bayesian inference and maximum-likelihood analyses were strongly affected by systematic biases, but the site-heterogeneous mixture model implemented in PhyloBayes avoided the false grouping of unrelated taxa exhibiting similar base composition and accelerated evolutionary rate. The inclusion of rRNAgenes and removal of fast-evolving sites with the observed variability sorting method for identifying sites deviating from the mean rates improved the phylogenetic inferences under a site-heterogeneous model, correctly recovering most deep branches of the Holometabola phylogeny. We suggest that the use of mitochondrial genome data for resolving deep phylogenetic relationships requires an assessment of the potential impact of substitutional saturation and compositional biases through data deletion strategies and by using site-heterogeneous mixture models. Our study suggests a practical approach for how to use densely sampled mitochondrial genome data in phylogenetic analyses. [ABSTRACT FROM AUTHOR]

Background: Nabidae, a family of predatory heteropterans, includes two subfamilies and five tribes. We previously reported the complete mitogenome of Alloeorhynchus bakeri, a representative of the tribe Prostemmatini in the subfamily Prostemmatinae. To gain a better understanding of architecture and evolution of mitogenome in Nabidae, mitogenomes of five species representing two tribes (Gorpini and Nabini) in the subfamily Nabinae were sequenced, and a comparative mitogenomic analysis of three nabid tribes in two subfamilies was carried out. Methodology/Principal Findings: Nabid mitogenomes share a similar nucleotide composition and base bias, except for the control region, where differences are observed at the subfamily level. In addition, the pattern of codon usage is influenced by the GC content and consistent with the standard invertebrate mitochondrial genetic code and the preference for A+T- rich codons. The comparison among orthologous protein-coding genes shows that different genes have been subject to different rates of molecular evolution correlated with the GC content. The stems and anticodon loops of tRNAs are extremely conserved, and the nucleotide substitutions are largely restricted to TψC and DHU loops and extra arms, with insertion-deletion polymorphisms. Comparative analysis shows similar rates of substitution between the two rRNAs. Long non-coding regions are observed in most Gorpini and Nabini mtDNAs in-between trnI-trnQ and/or trnS2-nad1. The lone exception, Nabis apicalis, however, has lost three tRNAs. Overall, phylogenetic analysis using mitogenomic data is consistent with phylogenies constructed mainly form morphological traits. Conclusions/Significance: This comparative mitogenomic analysis sheds light on the architecture and evolution of mitogenomes in the family Nabidae. Nucleotide diversity and mitogenomic traits are phylogenetically informative at subfamily level. Furthermore, inclusion of a broader range of samples representing various taxonomic levels is critical for the understanding of mitogenomic evolution in damsel bugs. [ABSTRACT FROM AUTHOR]

Background: An extinct new family of Pentatomomorpha, Venicoridae Yao, Ren & Cai fam. nov., with 2 new genera and 2 new species (Venicoris solaris Yao, Ren & Rider gen. & sp. nov. and Clavaticoris zhengi Yao, Ren & Cai gen. & sp. nov.) are described from the Early Cretaceous Yixian Formation in Northeast China. Methodology/Principal Findings: A cladistic analysis based on a combination of fossil and extant morphological characters clarified the phylogenetic status of the new family and has allowed the reconstruction of intersuperfamily and interfamily relationships within the Infraorder Pentatomomorpha. The fossil record and diversity of Pentatomomorpha during the Mesozoic is discussed. Conclusions/Significance: Pentatomomorpha is a monophyletic group; Aradoidea and the Trichophora are sister groups; these fossils belong to new family, treated as the sister group of remainder of Trichophora; Pentatomoidea is a monophyletic group; Piesmatidae should be separated as a superfamily, Piesmatoidea. Origin time of Pentatomomorpha should be tracked back to the Middle or Early Triassic. [ABSTRACT FROM AUTHOR]

Many of true bugs are important insect pests to cultivated crops and some are important vectors of human diseases, but few cladistic analyses have addressed relationships among the seven infraorders of Heteroptera. The Enicocephalomorpha and Nepomorpha are consider the basal groups of Heteroptera, but the basal-most lineage remains unresolved. Here we report the mitochondrial genome of the unique-headed bug Stenopirates sp., the first mitochondrial genome sequenced from Enicocephalomorpha. The Stenopirates sp. mitochondrial genome is a typical circular DNA molecule of 15, 384 bp in length, and contains 37 genes and a large non-coding fragment. The gene order differs substantially from other known insect mitochondrial genomes, with rearrangements of both tRNA genes and protein-coding genes. The overall AT content (82.5%) of Stenopirates sp. is the highest among all the known heteropteran mitochondrial genomes. The strand bias is consistent with other true bugs with negative GC-skew and positive AT-skew for the J-strand. The heteropteran mitochondrial atp8 exhibits the highest evolutionary rate, whereas cox1 appears to have the lowest rate. Furthermore, a negative correlation was observed between the variation of nucleotide substitutions and the GC content of each proteincoding gene. A microsatellite was identified in the putative control region. Finally, phylogenetic reconstruction suggests that Enicocephalomorpha is the sister group to all the remaining Heteroptera. [ABSTRACT FROM AUTHOR]