Species concept and nomenclatural changes within the genera Elliptochloris and Pseudochlorella (Trebouxiophyceae) based on an integrative approach

The genera Elliptochloris and Pseudochlorella were erected for Chlorella‐like green algae producing two types of autospores and cell packages, respectively. Both genera are widely distributed in different soil habitats, either as free living or as photobionts of lichens. The species of these genera are often difficult to identify because of the high phenotypic plasticity and occasional lack of characteristic features. The taxonomic and nomenclatural status of these species, therefore, remains unclear. In this study, 34 strains were investigated using an integrative approach. Phylogenetic analyses demonstrated that the isolates belong to two independent lineages of the Trebouxiophyceae (Elliptochloris and Prasiola clades) and confirmed that the genera are not closely related. The comparison of morphology, molecular phylogeny, and analyses of secondary structures of SSU and ITS rDNA sequences revealed that all of the strains belong to three genera: Elliptochloris, Pseudochlorella, and Edaphochlorella. As a consequence of the taxonomic revisions, we propose two new combinations (Elliptochloris antarctica and Pseudochlorella signiensis) and validate Elliptochloris reniformis, which is invalidly described according to the International Code for Nomenclature (ICN), by designating a holotype. To reflect the high phenotypic plasticity of P. signiensis, two new varieties were described: P. signiensis var. magna and P. signiensis var. communis. Chlorella mirabilis was not closely related to any of these genera and was, therefore, transferred to the new genus Edaphochlorella. All of the taxonomic changes were highly supported by all phylogenetic analyses and were confirmed by the ITS‐2 Barcodes using the ITS‐2/CBC approach.     

五种蝽科昆虫的细胞分类学研究（半翅目：异翅亚目）

研究了5种中国蝽科昆虫的核型和染色体的减数分裂行为,并采用核型分析软件对第一次减数分裂中期的染色体进行核型分析。结果表明：驼蝽Brachycerocoris camalus Costa、滴蝽Dybowskyia reticulata(Dallas）和红玉蝽Hoplistodera pulchra Yang3个种的染色体组成均为2n（♂）＝14,具有X－Y性别决定机制;减数分裂行为比较一致,但在中期－Ⅰ时,常染色体和性染色体的排列方式各不相同,可为蝽科昆虫的形态分类及系统发育提供有用的证据。二星蝽Eysarcoris guttiger(Thunberg）的染色体组成为2n（♂）＝15,具有X1X2Y性别决定机制,进一步证明了在半翅目昆虫的性染色体进化中碎片化过程起着很重要的作用;黑斑二星蝽Eysarcoris fabricii(Kirkaldy）的染色体组成为2n（♂）＝16,具有X－Y性别决定机制。后2种的核型结果,可为二星蝽属分类的进一步研究提供参考。     

基于18S rDNA序列的蝽次目(半翅目：异翅亚目)

利用18SrDNA分子约1 912 bp的序列对蝽次目21个科53个种进行系统发育分析。运用MP法、ML法和NJ法分析后的结果表明:蝽次目的单系性得到很高的支持;扁蝽总科成为毛点类的姐妹群;毛点类基本确定为两大分支:一支包含蝽总科和红蝽总科;另一支主要由长蝽总科、缘蝽总科和南蝽总科组成;长蝽总科和缘蝽总科都是多系;长蝽总科中,跷蝽科和皮蝽科的关系最近,构成姐妹群,位于整个毛点类的基部;与长蝽总科中另外两个科长蝽科和地长蝽科的关系很远。说明利用18SrDNA分子对研究蝽次目的系统发育关系是适合的,能够重建蝽次目;扁蝽总科和蝽总科单系性的结果与形态学的研究以及Li et al (2005)的研究一致;但较Li et al(2005)的研究更进一步把红蝽总科从广义的缘蝽总科中分出来;并建议皮蝽科作为一个独立的总科更合适。     

Diversity and evolution of the Wolbachia endosymbionts of Bemisia (Hemiptera: Aleyrodidae) whiteflies

Wolbachia is the most prevalent symbiont described in arthropods to date. Wolbachia can manipulate host reproduction, provide nutrition to insect hosts and protect insect hosts from pathogenic viruses. So far, 13 supergroups of Wolbachia have been identified. The whitefly Bemisia tabaci is a complex containing more than 28 morphologically indistinguishable cryptic species. Some cryptic species of this complex are invasive. In this study, we report a comprehensive survey of Wolbachia in B. tabaci and its relative B. afer from 1658 insects representing 54 populations across 13 provinces of China and one state of Australia. Based on the results of PCR or sequencing of the 16S rRNA gene, the overall rates of Wolbachia infection were 79.6% and 0.96% in the indigenous and invasive Bemisia whiteflies, respectively. We detected a new Wolbachia supergroup by sequencing five molecular marker genes including 16S rRNA, groEL, gltA, hcpA, and fbpA genes. Data showed that many protein‐coding genes have limitations in detecting and classifying newly identified Wolbachia supergroups and thus raise a challenge to the known Wolbachia MLST standard analysis system. Besides, the other Wolbachia strains detected from whiteflies were clustered into supergroup B. Phylogenetic trees of whitefly mitochondrial cytochrome oxidase subunit I and Wolbachia multiple sequencing typing genes were not congruent. In addition, Wolbachia was also detected outside the special bacteriocytes in two cryptic species by fluorescence in situ hybridization, indicating the horizontal transmission of Wolbachia. Our results indicate that members of Wolbachia are far from well explored.     

Similarities and spatial variations of bacterial and fungal communities in field rice planthopper (Hemiptera: Delphacidae) populations

Rice planthoppers are notorious plant sap‐feeding pests which cause serious damage. While several microbes in rice planthoppers have been broadly characterized, the abundance and diversity of bacteria and fungi in field planthoppers are largely unknown. This study investigated the bacterial and fungal community compositions of Chinese wild rice planthoppers Laodelphax striatellus and Sogatella furcifera using parallel 16S rRNA gene amplicon and internal transcribed space region sequencing. The bacteria varied significantly between the species and were partitioned significantly by sex, tissues and host environments in each species. The majority of bacteria were affiliated with the genera Wolbachia, Cardinium, Rickettsia and Pantoea. The abundance of Wolbachia was negatively correlated with that of Cardinium in both planthopper species. Compared with bacteria, the abundance and diversity of fungi did not differ between sexes but both were enriched in the gut. The bacterial community as a whole showed no significant correlation with the fungal community. The majority of fungi were related to Sarocladium, Alternaria, Malassezia, Aspergillus and Curvularia. A phylogenetic analysis revealed that these fungi were closely related to botanic symbionts or pathogens. Our results provide novel insights into the bacteria and fungi of rice planthoppers.     

Rapid diagnosis of the invasive wax scale,Ceroplastes rusci Linnaeus (Hemiptera: Coccoidea: Coccidae) using nested PCR

The fig wax scale, Ceroplastes rusci (Linnaeus) (Hemiptera: Coccoidea: Coccidae), is an invasive fruit pest of Afrotropical origin and potentially could become a serious threat to commercial fruit crops in China. C. rusci is difficult to identify owing to the shortage of easily distinguishable morphological characters. A rapid, accurate and reliable method to identify C. rusci in quarantine work is needed to detect further spread. In the present study, we describe a nested PCR method for the molecular identification of C.rusci. The nested PCR primers were designed based on variations in the barcode region of COI sequences between C. rusci and five other Ceroplastes species. A 200‐bp fragment was successfully amplified from 96 C. rusci individuals of seven geographical populations in China and Vietnam, and 13 individuals of two populations in Italy (the type country for C. rusci). These provided diagnostic bands that were not observed in any of five other Ceroplastes species widely distributed in China, namely, C. ceriferus (Fabricius), C. floridensis Comstock, C. japonicus Green, C. pseudoceriferus Green and C. rubens Maskell. Sensitivity tests revealed that diagnostic bands were generated even with a DNA template concentration of ~1.5 × 10^?5 ng/μl, and with average DNA template concentrations for adult females, single first‐instar nymphs and eggs of 14.7, 6.3 and 3.0 ng/μl, respectively. Our study demonstrates that the molecular diagnosis of C. rusci using nested PCR is rapid and accurate and shows potential in plant quarantine programmes.     

First Philippine record of the parasitoid,Comperiella sp. (Hymenoptera: Encyrtidae): a potential biocontrol agent against Aspidiotus rigidus (Hemiptera: Diaspididae)

The encyrtid genus Comperiella Howard has so far not been reported in the Philippines, where there is currently an outbreak of the coconut scale insect Aspidiotus rigidus Reyne particularly in the southern parts of the island of Luzon and in some areas in Mindanao. Among Comperiella species, only C. unifasciata Ishii has been reported as a parasitoid of A. rigidus. We report not only new sightings of this parasitoid genus in the Philippines from surveys conducted in parts of the provinces of Laguna and Batangas, but also the discovery of a possibly new species that, like C. unifasciata, has been found to parasitize A. rigidus at a high rate. These findings have presented a potential of biological control against the coconut scale insect problem that has threatened the coconut industry in the country.     

Flood pulses drive the temporal dynamics of assemblages of aquatic insects (Heteroptera and Coleoptera) in a temperate floodplain

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A preliminary phylogeny of the Pentatomomorpha (Hemiptera: Heteroptera) based on nuclear 18S rDNA and mitochondrial DNA sequences

Pentatomomorpha is the second suborder in size only to Cimicomorpha in Heteroptera. However, the phylogenetic relationships among members of the suborder are not well established. Sequences from partial nuclear ribosomal 18S gene and mitochondrial COX1 gene were analyzed separately and in combination to generate a preliminary molecular phylogeny of Pentatomomorpha based on 40 species representing 17 putative families. Analyses of the combined sequence data provided a better-resolved and more robust hypothesis of Pentatomomorpha phylogeny than did separate analyses of the individual genes. The phylogenies were mostly congruent with morphological studies. Results strongly supported the monophyly of the infraorder Pentatomomorpha, and the placement of Aradoidea as sister to Trichophora. The monophyletic Trichophora was grouped into two major lineages, one being the superfamily Pentatomoidea, and the other comprising Lygaeoidea, Coreoidea, and Pyrrhocoroidea. The analysis of the ML and ME trees of combined dataset supported the monophyletic Pentatomoidea. In all analysis the Pyrrhocoroidea was polyphyletic; the monophyletic Lygaeoidea was supported only in the analysis of ME tree, and Coreoidea was polyphyletic except in the MP tree of combined dataset. The molecular and morphylogical data both indicated that the family Coreoidae should be revised subsequently. Our phylogenetic results suggested that the COX1 segment alone might not be an optimal molecular marker for the phylogeny of Pentatomomorpha.     

Host plant volatiles responsible for the invasion of Stenotus rubrovittatus (Heteroptera: Miridae) into paddy fields

We investigated the attractiveness of synthetic volatile blends or individual volatiles of flowering rice panicles or flowering Scirpus juncoides spikelets to the sorghum plant bug Stenotus rubrovittatus (Matsumura). None of the individual chemicals tested attracted either sex of the bug. Synthetic volatile blends of flowering rice panicles composed of geranyl acetone, β‐caryophyllene, n‐decanal, methyl salicylate, β‐elemene and n‐tridecene attracted females. The synthetic blend of volatiles was just as attractive as natural flowering rice panicles to females. Other synthetic blends did not attract the bug. We sampled headspace volatiles from flowering S. juncoides spikelets with solid‐phase microextraction and analysed them using gas chromatography–mass spectrometry. The main volatile emitted from S. juncoides was β‐caryophyllene, one of the major volatile components of flowering rice panicles. β‐Elemene was a common volatile found in flowering rice panicles and flowering S. juncoides spikelets. Therefore, we investigated the attractiveness of synthetic blends of flowering rice panicles and S. juncoides spikelets composed of β‐caryophyllene and β‐elemene. The synthetic blend of flowering S. juncoides spikelets significantly attracted males but not females. The synthetic blend of flowering rice panicles composed of β‐caryophyllene and β‐elemene did not attract either sex. These results suggest that β‐caryophyllene and β‐elemene are common active compounds responsible for attractiveness of flowering rice panicles and S. juncoides spikelets although some of the other volatile components act synergistically with these two compounds in natural plant odours.     

Variation of life‐history parameters of Planococcus ficus (Hemiptera: Pseudococcidae) in response to grapevine nitrogen fertilization

The effects of different nitrogen fertilization regimes on body size and selected life‐history parameters (development time, survival, fecundity and fertility) of the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), were investigated on potted grapevines under laboratory and screenhouse conditions. In both trials, five groups of four grapevines each were supplied with 0, 0.25, 0.5, 1.0 or 2.0 g/l of ammonium nitrate fertilizer for a month and then artificially infested with 200 first‐instar vine mealybugs (24 h of age). The concentration of nitrogen on grape leaves was measured during both experiments by a SPAD chlorophyll metre, showing statistical differences among treatments. The nitrogen fertilization significantly affected the investigated P. ficus parameters, providing consistent results in both laboratory and screenhouse trials. The vine mealybug females exhibited higher survival and fecundity, larger body size and lower development time on plants supplied with higher nitrogen fertilization rates. Survival, body size and fecundity of P. ficus were positively correlated with the leaf nitrogen concentration, whereas the development time was negatively correlated. Fertility did not vary significantly among treatments. Our results show that high nitrogen regimes increase the reproductive performance of P. ficus on grapevines and point out the importance of implementing balanced fertilization plans in grapevine IPM programs to reduce population densities and prevent insect outbreaks.     

Ulva (Chlorophyta,Ulvales) Biodiversity in the North Adriatic Sea (Mediterranean,Italy): Cryptic Species and New Introductions

Ulva Linnaeus (Ulvophyceae, Ulvales) is a genus of green algae widespread in different aquatic environments. Members of this genus show a very simple morphology and a certain degree of phenotypic plasticity, heavily influenced by environmental conditions, making difficult the delineation of species by morphological features alone. Most studies dealing with Ulva biodiversity in Mediterranean waters have been based only on morphological characters and a modern taxonomic revision of this genus in the Mediterranean is not available. We report here the results of an investigation on the diversity of Ulva in the North Adriatic Sea based on molecular analyses. Collections from three areas, two of which subject to intense shipping traffic, were examined, as well as historical collections of Ulva stored in the Herbarium Patavinum of the University of Padova, Italy. Molecular analyses based on partial sequences of the rbcL and tufA genes revealed the presence of six different species, often with overlapping morphologies: U. californica Wille, U. flexuosa Wulfen, U. rigida C. Agardh, U. compressa Linnaeus, U. pertusa Kjellman, and one probable new taxon. U. californica is a new record for the Mediterranean and U. pertusa is a new record for the Adriatic. Partial sequences obtained from historical collections show that most of the old specimens are referable to U. rigida. No specimens referable to the two alien species were found among the old herbarium specimens. The results indicate that the number of introduced seaweed species and their impact on Mediterranean communities have been underestimated, due to the difficulties in species identification of morphologically simple taxa as Ulva.     

Phylogenetic relationships within Adiaphanida (phylum Platyhelminthes) and the status of the crustacean‐parasitic genus Genostoma

The existence of the platyhelminth clade Adiaphanida—an assemblage comprising the well‐studied order Tricladida as well as two lesser known taxa, Prolecithophora and the obligate parasitic Fecampiida—is among the more surprising results of flatworm molecular systematics. Each of these three clades is itself largely well‐defined from a morphological point of view, although Adiaphanida at large, despite its strong support in molecular phylogenetic analyses, lacks known morphological synapomorphies. However, one taxon, the genus Genostoma, a parasite of the leptostracan crustacean Nebalia, rests uneasily within its current classification within the fecampiid family Genostomatidae; ultrastructural investigations on this taxon have uncovered a spermatogenesis reminiscent of Kalyptorhynchia, and a dorsal syncytium resembling the neodermatan tegument. Here, we provide molecular sequence data (nearly complete 18S and 28S rRNA) from a representative of Genostoma, with which we test hypotheses on the phylogenetic position of this taxon within Platyhelminthes, expanding upon a recently published phylum‐wide analysis, and applying novel alignment algorithms and substitution models. These analyses unequivocally position Genostoma as the sister group of Prolecithophora. However, even in taxon‐rich analyses, support for the position of the root of Adiaphanida is lacking, highlighting the need for new data types to study the phylogeny of this clade. Interestingly, our analyses also do not recover the monophyly of several taxa previously proposed, notably Continenticola within Tricladida and Protomonotresidae within Prolecithophora. In light of this phylogeny and the distinctive morphology (especially, spermatogenesis) of Genostoma, we advocate for a redefinition of the family Genostomatidae, outside of both Fecampiida and Prolecithophora, to encompass the members of this unique genus of parasites. Within Fecampiida, the family Piscinquilinidae fam. nov. is erected to accommodate the vertebrate‐parasitic Piscinquilinus, formerly Genostomatidae.     

A new record for Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) species complex of Turkey

In this study, species complex of Turkish Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations was determined by PCR‐based DNA analysis. According to phylogenetic analyses, the B. tabaci samples have been identified within three generic groups. A major part of the samples belonged to two invasive species, either Middle East–Asia Minor 1 (MEAM1) or Mediterranean (MED). In addition to these two invasive species, several samples collected from greenhouses and cotton fields have been found to be related to Middle East–Asia Minor 2 (MEAM2), which is the first record of Turkish B. tabaci species complex.     

Morphology and Phylogenetic Position of Two New Gregarine Species (Apicomplexa: Eugregarinorida) Parasitizing the Lubber Grasshopper Taeniopoda centurio (Drury, 1770) (Insecta: Orthoptera: Romaleidae) in Mexico

Eugregarines are understudied apicomplexan parasites of invertebrates inhabiting marine, freshwater, and terrestrial environments. Most currently known terrestrial eugregarines have been described parasitizing the gut from less than 1% of total insect diversity, with a high likelihood that the remaining insect species are infected. Eugregarine diversity in orthopterans (grasshoppers, locusts, katydids, and crickets) is still little known. We carried out a survey of the eugregarines parasitizing the Mexican lubber grasshopper, Taeniopoda centurio, an endemic species to the northwest of Mexico. We described two new eugregarine species from the gut of the host: Amoebogregarina taeniopoda n. sp. and Quadruspinospora mexicana n. sp. Both species are morphologically dissimilar in their life‐cycle stages. Our SSU rDNA phylogenetic analysis showed that both species are phylogenetically distant to each other, even though they parasitize the same host. Amoebogregarina taeniopoda n. sp. clustered within the clade Gregarinoidea, being closely related to Amoebogregarina nigra from the grasshopper Melanoplus differentialis. Quadruspinospora mexicana n. sp. clustered within the clade Actinocephaloidea and grouped with Prismatospora evansi, a parasite from dragonfly naiads. Amoebogregarina taeniopoda n. sp. and Q. mexicana n. sp. represent the first record of eugregarines found to infect a species of the family Romaleidae.     

Production of volatiles by the red seaweed Gelidium arbuscula (Rhodophyta): emission of ethylene and dimethyl sulfide

The effects of different light conditions and exogenous ethylene on the emission of volatile compounds from the alga Gelidium arbuscula Bory de Saint‐Vincent were studied. Special emphasis was placed on the possibility that the emission of ethylene and dimethyl sulfide (DMS) are related through the action of dimethylsulfoniopropionate (DMSP) lyase. The conversion of DMSP to DMS and acrylate, which is catalyzed by DMSP lyase, can indirectly support the synthesis of ethylene through the transformation of acrylate to ethylene. After mimicking the desiccation of G. arbuscula thalli experienced during low tides, the volatile compounds emitted were trapped in the headspace of 2 mL glass vials for 1 h. Two methods based on gas chromatography/mass spectrometry revealed that the range of organic volatile compounds released was affected by abiotic factors, such as the availability and spectral quality of light, salinity, and exogenous ethylene. Amines and methyl alkyl compounds were produced after exposure to white light and darkness but not after exposure to exogenous ethylene or red light. Volatiles potentially associated with the oxidation of fatty acids, such as alkenes and low‐molecular‐weight oxygenated compounds, accumu‐lated after exposure to exogenous ethylene and red light. Ethylene was produced in all treatments, especially after exposure to exogenous ethylene. Levels of DMS, the most abundant sulfur‐compound that was emitted in all of the conditions tested, did not increase after incubation with ethylene. Thus, although DMSP lyase is active in G. arbuscula, it is unlikely to contribute to ethylene synthesis. The generation of ethylene and DMS do not appear to be coordinated in G. arbuscula.