Speciation by host-switching in pinyon Cinara (Insecta: Hemiptera: Aphididae)

Parasite-host cospeciation has received much attention as an important mechanism in the diversification of phytophagous insects. However, studies have shown that for certain taxa, it is not host fidelity but host-switching that plays the critical role in speciation. Cinara are aphids (Insecta: Hemiptera: Aphididae: Lachninae) that feed exclusively on the woody parts of conifers of the Cupressaceae and Pinaceae. They are unusual aphids because most Pinaceae play host to several species of Cinara. The aphids show relatively strong host fidelity, and as a consequence historically have been treated based on the taxonomy of their hosts. The historical paradigm of aphid evolution implies that Cinara species have radiated to different parts of the same host species and/or speciated with their host. Using mitochondrial cytochrome oxidase 1 and nuclear elongation factor 1-alpha DNA sequences, we performed molecular phylogenetic analysis of Cinara species, concentrating on those associated with pinyon pines in the southwestern USA. We determined that switching hosts has played a key role in the speciation of the genus, reflected in the polyphyly of pinyon-feeding Cinara. Furthermore, species sharing a common feeding site on different hosts were more closely related to each other than to those sharing the same host but at different feeding sites, suggesting that feeding site fidelity plays a more important role in speciation than does host fidelity in general. This study also elucidated the primary taxonomy of various species: it suggested that Cinara rustica Hottes is a junior synonym of C. edulis (Wilson) and that C. wahtolca Hottes represents two species on the two different pinyon pine species, Pinus edulis Englem. and P. monophylla Torr. & Frem.     

Species identification of aphids (Insecta: Hemiptera: Aphididae) through DNA barcodes

A 658-bp fragment of mitochondrial DNA from the 5' region of the mitochondrial cytochrome c oxidase 1 (COI) gene has been adopted as the standard DNA barcode region for animal life. In this study, we test its effectiveness in the discrimination of over 300 species of aphids from more than 130 genera. Most (96%) species were well differentiated, and sequence variation within species was low, averaging just 0.2%. Despite the complex life cycles and parthenogenetic reproduction of aphids, DNA barcodes are an effective tool for identification.     

Comparative morphology of female genitalia and the copulatory mechanism in Trypetimorphini (Hemiptera,Fulgoromorpha, Tropiduchidae)

A comparative morphological study of the female genitalia in Trypetimorphini shows that Caffrommatissus trimaculatus has a monotrysian condition, while species of Trypetimorpha and Ommatissus are ditrysian. Dissection of Trypetimorpha biermani Dammerman in copula shows that spermatozoa are first deposited in the bursa copulatrix and probably are transferred secondarily into the spermatheca. Maintenance of copulatory position is achieved by the male's gonostyli gripping the female's VIII gonapophyses, by endosoma inflation, and by eversion of antero-ventrally directed endosomal processes. Existence of the ditrysian condition in Fulgoromorpha is disputed and the presence of a copulatory-duct has to be interpreted as a neoformation in Tropiduchidae, although within this group it could have evolved several times independently.     

Inter-generic variation in the male genitalia of the Braconinae (Insecta, Hymenoptera, Braconidae)

Male genitalia belonging to representatives of a total of 72 genera of Old and New World Braconinae have been examined by light and scanning electron microscopy. On the basis of features of the volsellae (setosity), the parameres (setosity), the digitus (number of teeth, shape) and basal ring (posterior extension) it was possible to identify certain generic groupings which support the general suprageneric divisions of the subfamily based on other taxonomic characters. The male genitalia are thus shown to provide a potentially useful new set of characters for the higher level classification of the braconine genera.     

Comparative morphology of the external male genitalia in Lophogastrida, Stygiomysida, and Mysida (Crustacea, Eumalacostraca)

External organs associated with the male gonopore are described for 29 species covering for the first time all seven currently acknowledged, extant families of the orders Lophogastrida, Stygiomysida, and Mysida, and all ten subfamilies of the Mysidae (Mysida). The gonopores are located throughout on the structures of the coxa of the eighth thoracopods. The three orders are consistently differentiated based on their male genital characteristics. Species of the Stygiomysida genera Stygiomysis (Stygiomysidae) and Spelaeomysis (Lepidomysidae) share a closing apparatus formed by two laminar lobes flanking the genital orifice, an anterior setose lobe, and a posterior bare lobe; no tubular penes are developed. In contrast, the Lophogastrida are characterized by a bare, slot-like orifice without lobes; also, in this taxon, no tubular penes are developed. The gonopore is on the inner wall of the coxa without conspicuous elevation in the species of Eucopia (Eucopiidae) and Lophogaster (Lophogastridae) and on the top of an anvil-like elevation in Paralophogaster (Lophogastridae), or of a dome-shaped elevation in Gnathophausia and Neognathophausia (Gnathophausiidae). In all examined species of the Mysida, the gonopores show a closing apparatus formed by lobes; one or more of these lobes is setose in most species. Within the Mysida, the genus Hansenomysis (Petalophthalmidae) and most subfamilies of the Mysidae have well-developed paired penes with (sub) terminal orifice. Only Rhopalophthalmus (Rhopalophthalminae) lacks penes but has bilobate gonopores located without additional elevation at the inner distal corner of the strongly enlarged coxa of the eighth thoracopods; this coxa contains a large seminal vesicle. Within the variety of external male genitalia in the Eumalacostraca, the structures associated with the gonopores appear to be plesiomorphic in Lophogastrida. In the Mysida, they appear to be apomorphic and support the monophyly of this order with respect to the previously published, competing phylogenetic trees. This requires additional evidence in the case of the Stygiomysida.     

Comparative morphology study of the male genitalia in the tribe Astathini from China (Coleoptera: Cerambycidae)

The male genitalia of 13 species from four genera of Astathini were described and analyzed. The result showed that five genital characters, such as shape of the apex of 8th abdominal tergaum and sternum, ratio of the length of lateral lobes to tegmen, can be used to identify genera of Astathini; six characters, such as ratio of the length of lateral lobes to tegmen, ratio of the length of roof to lateral lobes, shape of the apex of ventral plate of median lobe, can be used to identify species in Bacchisa.     

Mitochondrial genome sequences effectively reveal deep branching events in aphids (Insecta: Hemiptera: Aphididae)

Over the past dozen years, considerable effort has been devoted to unravelling the higher‐level phylogenetic relationships of viviparous aphids (Aphididae). However, to date, there is still no commonly accepted phylogenetic hypothesis. In this study, we establish a robust phylogenetic framework for the Aphididae based on mitochondrial genome sequences of 35 aphid species, 22 of which are newly reported. Phylogenetic inferences are performed using multiple data sets, alternative partitioning schemes and different model‐based methods. Our analyses result in well‐supported backbone relationships for the major lineages of aphids, suggesting the feasibility of mitogenome data for resolving phylogenetic questions in aphids. Mindarinae is strongly supported as the earliest branching lineage within Aphididae. A monophyletic clade comprising Calaphidinae, Phyllaphidinae and Saltusaphidinae is corroborated to be the sister group to the species‐richest subfamily Aphidinae. In addition, the morphologically defined subfamily Eriosomatinae is uncovered to be non‐monophyletic.     

Male-specific flight apparatus development in Acyrthosiphon pisum (Aphididae, Hemiptera, Insecta): comparison with female wing polyphenism

Wing polymorphisms observed in many Insecta are important topics in developmental biology and ecology; these polymorphisms are a consequence of trade-offs between flight and other abilities. The pea aphid, Acyrthosiphon pisum, possesses 2 types of wing polymorphisms: One is a genetic wing polymorphism occurring in males, and the other is an environmental wing polyphenism seen in viviparous females. Although genetic and environmental cues for the 2 wing polymorphisms have been studied, differences in their developmental regulation have not been elucidated. In particular, there is little knowledge regarding the developmental processes in male wing polymorphism. Therefore, in this study, the development of flight apparatuses and external morphologies was compared among 3 male wing morphs (winged, wingless, and intermediate). These male developmental processes were subsequently compared with those of female wing morphs. Developmental differences between the male and female polymorphisms were identified in flight muscle development and degeneration but not in wing bud development. Furthermore, the nymphal periods of wingless and intermediate males were significantly shorter than that of winged males, indicating the adaptive significance of male winglessness. Overall, this study indicates that the male and female wing polymorphisms are based on different regulatory systems for flight apparatus development, which are probably the result of different adaptations under different selection pressures.     

Morphological and ultrastructural organization of the male genital apparatus of some Aphididae (Insecta, Homoptera)

Ultrastructural investigations on the amphigonic reproductive mechanisms in Aphidoidea (Homoptera, Sternorryncha) species, of which little is known in the literature, can provide useful information on their reproductive biology. Morphological and ultrastructural investigations were carried out on the reproductive tract and on spermatozoa from sexually mature males of five species belonging to three subfamilies of Aphidoidea. The organization of the reproductive tract and of spermatozoa appears simple and similar in the examined species. Each testis consists of three follicles containing many cysts arranged in a progressive order of maturation from the distal to the proximal tract; spermiogenesis only occurs in sexually mature males, ending with the organization of sperm bundles. Gametes are neatly arranged in each bundle and kept together by a cap showing a particular organization. The distal tract of each spermiduct is enlarged and full of gametes; close to the testis the two spermiducts merge together, except in Drepanosiphum platanoidis where the spermiducts run independently. The various tracts of each examined gland showed no peculiar differences either in the same species or among the species. Some interesting hypotheses are proposed in this work about the probable roles of the investigated structures in the reproductive mechanisms of these insects.     

两种毛蚜线粒体基因组比较分析

【目的】线粒体基因组分析已被应用于昆虫系统发育研究。本研究以蚜科Aphididae重要类群毛蚜亚科物种为代表,测定并比较分析了该类蚜虫的线粒体基因组特征,探讨了基于线粒体基因组信息的蚜虫系统发育关系重建。【方法】以毛蚜亚科三角枫多态毛蚜Periphyllus acerihabitans Zhang和针茅小毛蚜Chaetosiphella stipae Hille Ris Lambers,1947为研究对象,利用长短PCR相结合的方法测定线粒体基因组的序列,分析了基因组的基本特征;基于在线t RNAscan-SE Search Server搜索方法预测了t RNA的二级结构;基于12个物种(本研究获得的2个物种和10个Gen Bank上下载的物种数据)的蛋白编码基因(PCGs)序列,利用最大似然法和贝叶斯法重建了蚜科的系统发育关系。【结果】两种毛蚜均获得了约94%的线粒体基因组数据,P.acerihabitans获得了14 908 bp,控制区为1 205 bp;C.stipae获得了13 893 bp,控制区为609 bp。两种毛蚜同时获得33个基因,包含接近完整的13个蛋白编码基因(PCGs)(nad5不完整),18个tRNA,2个rRNA基因;ka/ks值表明,C.stipae的进化速率更快。从基因组组成、基因排列顺序、核苷酸组成分析、密码子使用情况、t RNA二级结构等特征来分析,两种蚜虫线粒体基因组基本特征相似。系统发育重建结果表明毛蚜亚科、蚜亚科的单系性得到了支持,毛蚜亚科位于蚜科的基部位置。【结论】两种毛蚜线粒体基因组的基本特征相似,符合蚜虫线粒体基因组的一般特征,两种线粒体基因组的长度差异主要来自控制区长度的不同;系统发育重建支持毛蚜亚科与蚜亚科的单系性,毛蚜亚科位于蚜科较为基部的位置。研究结果为蚜虫类系统发育重建提供了参考。     

Comparative morphology of the spiracles of the Papilionidae,Sphingidae, and Saturniidae (Insecta: Lepidoptera)

The morphology, ultrastructure, and innervation of the spiracles of the instars and adults of representatives of three lepidopteran families were examined: Ornithoptera priamus poseidon and Pachliopta aristolochiae (Papilionidae), Attacus atlas (Saturniidae), and Acherontia atropos (Sphingidae).Peritreme and atrium show stage- and family-specific structures for protecting the internal valve apparatus. The gross morphology of the cuticular valve mechanism is uniform within the three families, consisting of a rigid bow and a movable bar with a lever. In adult Papilionidae, all cuticular parts (bow, bar and lever) of the valve are innervated by multipolar dendrites. Internal or external cuticular chemo- or hygroreceptors, which could participate in the regulation of respiration, could not be detected in any stage. The closing muscle inserts between the tip of the lever and the base of the bar, and is innervated only by motor neurons. The elasticity of the cuticular system and an opener are the antagonists to the closing muscle. The spiracular opener of the adult Papilionidae and of all instars of the moths is an elastic ligament. The opener of the larval and pupal spiracles of the Papilionidae, however, is a single thickened muscle fiber surrounded by an elastic sheath of connective tissue. As it contains motor and multipolar sensory neurons, we assume that it may function as a stretch receptor for controlling the spiracular opening state.     

Evolution of the planthoppers (Insecta: Hemiptera: Fulgoroidea)

The planthopper superfamily Fulgoroidea (Insecta: Hemiptera) comprises approximately 20 described insect families, depending on which classification is followed. Multiple competing hypotheses of fulgoroid phylogeny have been published, based on either morphological character coding or DNA sequence data; however, those hypotheses disagree in several key aspects regarding the evolution of planthoppers. The current paper seeks to test these hypotheses, including the Asche (Asche, M. 1987. Preliminary thoughts on the phylogeny of Fulgoromorpha (Homoptera Auchenorrhyncha). In: Proceedings of the 6th Auchenorrhyncha Meeting, Turin, Italy, 7-11 September, 1987, pp. 47-53.) hypothesis of a trend in ovipositor structure, which may be correlated with planthopper feeding ecology. Presented here are phylogenetic reconstructions of Fulgoroidea based on analysis of DNA nucleotide sequence data from four loci (18S rDNA, 28S rDNA, Histone 3, and Wingless) sequenced from 83 exemplar taxa representing 18 planthopper families and outgroups. Data sets were analyzed separately and in various combinations under the maximum parsimony criterion, and the total combined dataset was analyzed via both maximum parsimony and partitioned Bayesian criteria; results of the combined analyses were concordant across reconstruction paradigms. Relationships recovered suggest several major planthopper lineages, including: (1) Delphacidae+Cixiidae; (2) Kinnaridae+Meenoplidae; (3) Fulgoridae+Dictyopharidae; (4) Lophopidae+Eurybrachidae (possibly+Flatidae); (5) Ricaniidae+Caliscelidae (possibly+Tropiduchidae). Results also suggest the placement of Achilixiidae outside of Cixiidae and of Tettigometridae as one of the more recently diversified lineages within Fulgoroidea. The resulting phylogeny supports Asche's (1987) hypothesis of a functional trend in ovipositor structure across families.     

B chromosomes in Sternorrhyncha (Hemiptera, Insecta)

In the hemipteroid insects of the suborder Sternorrhyncha, B chromosomes are relatively common in comparison with other suborders of Hemiptera. However, the occurrence of supernumerary chromosomes is restricted, in most cases, to several genera or closely related species. At least in some species of Psylloidea with the XY sex determination system, a mitotically stable B chromosome integrated into an achiasmatic segregation system with the X, and became fixed as a Y chromosome. In some Aphidoidea with a multiple X system of sex determination, B chromosomes appear to be in fact non-functional X chromosomes. Supernumerary chromosomes thus probably play an important role in the evolution of sex determination systems in Sternorrhyncha.     

A remarkable new species of Euragallia from Peru (Insecta, Hemiptera, Cicadellidae, Agalliini), including the description of a peculiar structure of the male genitalia

A new species of Euragallia Oman, 1938 from Peru (Pasco Department) is described and illustrated. Euragallia batmanisp. n. can be distinguished from the other species of the genus by the very posteriorly pronounced male pygofer, with an apical hook-like projection, and by the well-developed dorsal area of the aedeagal base, resembling the open wings of a bat. With the addition of Euragallia batmani sp. n., the number of Euragallia species is increased to 21. Only one additional species of the genus is recorded from Peru (Euragallia prion Kramer, 1976). A comparison between the new species and Euragallia prion is provided. A conspicuous structure, which connects the subgenital plates to the styles, is described in detail and named.     

The Auchenorrhyncha fauna of peat bogs in the Austrian part of the Bohemian Forest (Insecta,Hemiptera)

The first overview on the Auchenorrhyncha fauna of peat bogs of the Austrian Bohemian Forest is presented. Seven oligotrophic peat bog sites were studied in 2011 by suction sampler (“G-Vac”) and 93 Auchenorrhyncha species (with 7465 adult specimens) were recorded. Eleven species (about 18 % of the individuals) are tyrphobiontic or tyrphophilous. The relative species abundance plot is not very steep; the six most abundant species represent 50 % of the individuals. The most common species is Conomelus anceps (17 % of the individuals). Compared to the whole Austrian Auchenorrhyncha fauna, the fauna of peat bogs comprises distinctly more univoltine species and more species hibernating in nymphal stage. Densities of adult Auchenorrhyncha in peat bogs are low in spring (about 10–60 individuals per m²) and high in July, with up to 180 (±50) individuals per m². Disturbed peat bogs have higher species numbers and higher Auchenorrhyncha densities in total, but lower numbers and densities in peat bog specialists.