A secondary structural model of the 28S rRNA expansion segments D2 and D3 for Chalcidoid wasps (Hymenoptera: Chalcidoidea)

We analyze the secondary structure of two expansion segments (D2, D3) of the 28S ribosomal (rRNA)-encoding gene region from 527 chalcidoid wasp taxa (Hymenoptera: Chalcidoidea) representing 18 of the 19 extant families. The sequences are compared in a multiple sequence alignment, with secondary structure inferred primarily from the evidence of compensatory base changes in conserved helices of the rRNA molecules. This covariation analysis yielded 36 helices that are composed of base pairs exhibiting positional covariation. Several additional regions are also involved in hydrogen bonding, and they form highly variable base-pairing patterns across the alignment. These are identified as regions of expansion and contraction or regions of slipped-strand compensation. Additionally, 31 single-stranded locales are characterized as regions of ambiguous alignment based on the difficulty in assigning positional homology in the presence of multiple adjacent indels. Based on comparative analysis of these sequences, the largest genetic study on any hymenopteran group to date, we report an annotated secondary structural model for the D2, D3 expansion segments that will prove useful in assigning positional nucleotide homology for phylogeny reconstruction in these and closely related apocritan taxa.     

Chalcidoid wasps (Hymenoptera, Chalcidoidea) parasitizing on scales (Homoptera, Coccidae) in Vietnam: X. A peculiar new species of the genus Coccophagus Westwood (Aphelinidae)

Coccophagus tetrastichoides sp. n. is characterized by an uncommon combination of features, particularly, by the general habitus and by the submarginal and marginal veins connected as those in tetrastichine wasps. C. tetrastichoides sp. n. is a gregarious parasite of adult females of the myrmecophilous soft scale, Megalocryptes bambusicola Green, setting on living bamboo stems in nests of the ant Crematogaster sp.     

New data on the pteromalid wasps (Hymenoptera,Chalcidoidea: Pteromalidae) of Krasnodar Territory (Russia)

Three genera (Erdoesia Bou?ek, Metastenus Walker, and Novitzkyanus Bou?ek) and 24 species are recorded for the first time for the fauna of Russia; in addition, 39 species are new for the fauna of Krasnodar Territory. New host–parasite associations are revealed for 6 species of pteromalid wasps.     

A review of encyrtid wasps (Hymenoptera,Chalcidoidea, Encyrtidae) of Macaronesia

The review contains an annotated list of 62 species of Encyrtidae from Macaronesia with data on their distribution, hosts, and use in biological control of agricultural insect pests. An attempt is undertaken to classify most of them according to nine types of ranges and to separate species which were introduced to Macaronesia by the ecesis, i.e., accidentally with their hosts. Three genera are synonymized: Acerophagus E.A. Smith, 1880 (= Pseudaphycus Timberlake, 1916, syn. n.); Isodromus Howard, 1887 (= Eupoecilopoda Erdös et S. Novicky, 1955, syn. n.); Syrphophagus Ashmead, 1900 (= Tassonia Girault, 1921, syn. n.). Cerchysiella togashii Tachikawa, 1988 is placed in the genus Zaommoencyrtus Girault, 1916. Cerchysiella koenigsmanni (Trjapitzin, 1985) is considered a subjective synonym of C. latiscapus (Shafee et Fatma, 1984). The following replacement names are given: Acerophagus xuzhihongi Trjapitzin, nom. n. for A. clavatus Xu Zhihong, 1999 non A. clavatus Pilipjuk, 1981; and Anagyrus sergueii Trjapitzin, nom. n. for Anagyrus orbitalis Timberlake, 1941 non A. orbitalis (Ruschka, 1923). Material on encyrtids from the Macaronesian islands Tenerife and Madeira in the museums in Madrid, Helsinki and Washington were examined.     

New data on the Pteromalid wasps (Hymenoptera,Chalcidoidea: Pteromalidae) of the Russian Far East

Fourteen genera (Ardilea Graham, Glyphognathus Graham, Rhicnocoelia Graham, Eulonchetron Graham, Habritys Thomson, Heteroprymna Graham, Janssoniella Kerrich, Lyubana Bou?ek, Muscidifurax Girault et Sanders, Nazgulia Hedqvist, Notoglyptus Masi, Oxysychus Delucchi, Platygerrhus Thomson, and Stenetra Masi) and 81 species are recorded for the first time for the fauna of Russia; in addition, 13 species are new to the fauna of the Russian Far East.     

New data on the European fauna of encyrtid wasps (Hymenoptera, Chalcidoidea, Encyrtidae)

On the basis of examination of the collection of the Natural History Museum (london), an annotated list of 36 encyrtid species with new records for 12 countries is given: one species new for both Ukraine and Croatia; two, for Austria, Cyprus, and Norway; three, for U.K.; four, for Germany and Spain; five, for Bulgaria; six, for Italy; eight, for France, and twelve, for Greece.     

Euphorine phylogeny: the evolution of diversity in host-utilization by parasitoid wasps (Hymenoptera: Braconidae)

ABSTRACT.

• 1 New data on the phylogeny of the braconid subfamily Euphorinae supports the hypothesis that parasitism of adult insects by Euphorinae originated during parasitism of Chrysomelidae, a group whose larvae are ecologically coincident with adults.
• 2 Evolution of the habit of attacking the adult stage opened a new adaptive zone; subsequently the Euphorinae have diversified on to a phylogenetically greater variety of hosts than any other braconid subfamily.
• 3 Parasitism of eumastacid grasshoppers evolved from beetle parasitism in the tribe Perilitini.
• 4 The tribe Euphorini shows the greatest diversity of hosts utilized. Most attack Heteroptera; however, Chrysopopthorus diversified on to adult Chrysopidae, Euphoriella on to Psocoptera, and Cryptoxilos on to Scolytidae.
• 5 Parasitism of bark beetles (Scolytidae) has evolved independently in three genera: Cosmophorus, Cryptoxilos and Ropalophorus. This is the most specialized form of beetle parasitism by euphorines, since it involves direct parasitism of concealed hosts.
• 6 Parasitism of adult hymenopterans by the tribe Syntretini may be related to attacking hosts while they are foraging at flowers.
• 7 The pattern of diversification in the Euphorinae indicates several adaptive radiations within host orders, as well as a history of major host-shifts between phylogenetically distantly-related host groups: Coleoptera to Orthoptera; Coleoptera to Hymenoptera; Coleoptera to Heteroptera; Heteroptera to Neuroptera, Psocoptera, and back to Coleoptera. Both the‘host taxonomy’and‘host habitat’hypotheses of host-shifting are supported. Host-shifts have involved hosts occurring in the same micro-habitat and usually having similar feeding habits. This is consistent with current theory of host-location by means of host-produced kairomones and visual cues.

     

传粉和非传粉榕小蜂线粒体基因组进化差异

[目的]目前关于榕小蜂类群的线粒体基因组报道很少,本研究旨在探讨传粉和非传粉榕小蜂两个群体的线粒体基因组的进化差异.[方法]以15种榕小蜂的线粒体基因组(其中11种的线粒体基因组为新测定)数据为基础,采用比较线粒体基因组学方法,分析榕小蜂的线粒体基因组序列和进化特征.[结果]本研究新测定的11个榕小蜂物种的近全长线粒体...     

Seasonal variation in the reproductive strategy of the parasitic wasp Eulophus larvarum (Hymenoptera: Chalcidoidea: Eulophidae)

ABSTRACT. 1. Eulophus larvarum (L.) (Hymenoptera: Eulophidae) is a gregarious parasitoid of lepidopterous larvae feeding on broad-leaved trees. Normally there are two generations a year.
2. Sex ratio in the spring generation of larvae is female biased. The bias is probably due to local mate competition as progeny from one brood emerge from their pupae in close proximity to each other.
3. Sex ratio in the summer generation of larvae is near equality. Local mate competition is absent as individuals from the same brood become separated during the winter.
4. Variation in sex-ratio in the spring generation is consistent with a binomial model. Variation in sex ratio in the summer generation is much greater than expected from a binomial model and there is a large proportion of single-sex broods.
5. Two hypotheses are put forward to explain the summer generation pattern: virgin oviposition, and strong intersexual competition.
6. No differences in clutch size were found between the two generations.     

Mitochondrial DNA phylogeography of the Cotesia flavipes complex of parasitic wasps (Hymenoptera: Braconidae)

The Cotesia flavipes species complex of parasitic wasps are economically important worldwide for the biological control of lepidopteran stem borers. The complex currently comprises three species: Cotesia flavipes Cameron, C. sesamiae (Cameron) and C. chilonis (Matsumura) (Hymenoptera: Braconidae), which appear morphologically similar. Despite their economic importance, little is known about the genetic diversity and phylogeography of these parasitoids. Differences in the biology of geographic populations have generally been interpreted as genetic divergence among strains, but direct genetic evidence is lacking. In Australia, several stem borer pests in neighbouring countries have been identified as significant threats to the sugar industry. However, the status of C. flavipes in Australia is unknown. To examine the genetic variation among worldwide populations of the C. flavipes complex and investigate the status of the Australian C. flavipes-like species, partial sequence data were generated for mitochondrial gene regions, 16S rRNA and COI. Parsimony, minimum evolution and Bayesian analyses based on 21 geographic populations of the complex and four outgroups supported the monophyly of the complex and the existence of genetically divergent populations of C. flavipes and C. sesamiae. The geographically isolated Australian haplotypes formed a distinct lineage within the complex and were ~3.0% divergent from the other species. The results indicated that historical biogeographic barriers and recent biological control introductions play an important role in structuring lineages within these species. This study provides a phylogeographical context for examining adaptive evolution and host range within biologically divergent strains of the C. flavipes complex.     

Contrasting rates of mitochondrial molecular evolution in parasitic Diptera and Hymenoptera

We investigated the putative association between the parasitic lifestyle and an accelerated rate of mt genetic divergence, compositional bias, and gene rearrangement, employing a range of parasitic and nonparasitic Diptera and Hymenoptera. Sequences were obtained for the cox1, cox2, 16S, 28S genes, the regions between the cox2 and atp8 genes, and between the nad3 and nad5 genes. Relative rate tests indicated generally that the parasitic lifestyle was not associated with an increased rate of genetic divergence in the Diptera but reaffirmed that it was in the Hymenoptera. Similarly, a departure from compositional stationarity was not associated with parasitic Diptera but was in parasitic Hymenoptera. Finally, mitochondrial (mt) gene rearrangements were not observed in any of the dipteran species examined. The results indicate that these genetic phenomena are not accelerated in parasitic Diptera compared with nonparasitic Diptera. A possible explanation for the differences in the rate of mt molecular evolution in parasitic Diptera and Hymenoptera is the extraordinary level of radiation that has occurred within the parasitic Hymenoptera but not in any of the dipteran parasitic lineages. If speciation events in the parasitic Hymenoptera are associated with founder events, a faster rate of molecular evolution is expected. Alternatively, biological differences between endoparasitic Hymenoptera and endoparasitic Diptera may also account for the differences observed in molecular evolution.     

Cocoon silk chemistry in parasitic wasps (Hymenoptera, Ichneumonoidea) and their hosts

Bulk amino acid compositions of larval cocoon silks of 24 species of ichneumonoid parasitic wasps, representing 13 subfamilies that kill the host in a larval or prepupal stage, are compared with those of their hosts to test the hypothesis that amino acid compositions of major protein products should, in certain cases, be similar on energetic grounds. Although substantial variation in amino acid composition was found among both parasitoids and hosts, suggesting the production of different types of silks, no significant general matching was detected. However, the trend in the degree of similarity observed was in the direction predicted by a priori consideration of the nature of the parasitoid – host association. Lack of a general association may be explained by the very simple silk glands of the parasitic wasps and by the fact that, in most cases, their hosts are not completely consumed at a time when they are likely to contain any large reserves of silk proteins. The three species of Cotesia (Braconidae: Microgastrinae) investigated stood out in that their silks showed considerable interspecific variation in molar percentage amino acid composition, and this might be associated with their apparent utilization of α-helical silks rather than fibroins.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 161–170.     

Attraction of Encyrtid wasps (Hymenoptera,Chalcidoidea: Encyrtidae) to a peach orchard agrocenosis in the Republic of Moldova

A total of 26 species from 19 genera of Encyrtidae were recorded in peach orchards in the environs of Chisinau, Moldova. The species affecting the numbers of such peach pests as the Oriental fruit moth Grapholita molesta Busck, the peach twig borer Anarsia lineatella Z., the San Jose scale Diaspidiotus perniciosus Comst., and the gooseberry scale Eulecanium coryli L., are listed. The encyrtid parasites of the potential peach pests in Moldova, and also the hyperparasites and parasites of beneficial predatory insects, are considered. Proteincarbohydrate mixture (PCM) and methyl salicylate (MeSA) were most effective for attraction of encyrtid wasps in April and the first half of May, providing 7.0- and 3.2-fold increase in the parasite numbers as compared with the control. In the second decade of May and in June, the increase was 3.6 times on PCM, 1.8 times on MeSA, and 2.6 times on nectariferous plants. From the end of June the efficiency of PCM and MeSA only slightly exceeded the control level while nectariferous plants were most effective, yielding a more than twofold increase in the numbers of encyrtids.     

New species of chalcidoid wasps of the family Eurytomidae (Hymenoptera,Chalcidoidea) from arid Palaearctic regions

Five new species of chalcidoid wasps of the family Eurytomidae are described: four from Israel and one from Kazakhstan. Tetramesa pavliceki Zerova, sp. n. (cylindrica species group) is closely related to T. scheppugi Schlecht., but differs in the more elongate flagellar segments, longer genae, and smooth metasomal tergites. Eurytoma nevoi Zerova, sp. n. is similar to E. sabulosa Erd. and E. bicolorata Zer. (phragmiticola species group), differs from these species in the longer marginal vein, punctate propodeum, and longer flagellar segments. E. oreni Zerova, sp. n. belongs to the fumipennis species group. It is closely related to E. monticola Zer., but differs in the more convex scape, longer postmarginal vein, and yellow legs. E. simutniki Zerova, sp. n. belongs to the robusta species-group. It resembles E. heriadi Zer., but differs in the longer flagellar segments of the female and in the shorter postmarginal vein. Nikanoria mamayevi Zerova, sp. n. is similar to N. stigma Zer., but differs in the more elongate metasoma, longer flagellar segments of both sexes, and larger yellow spots on the pronotum.     

Mitochondrial genome evolution in fire ants (Hymenoptera: Formicidae)

Background  

Complete mitochondrial genome sequences have become important tools for the study of genome architecture, phylogeny, and molecular evolution. Despite the rapid increase in available mitogenomes, the taxonomic sampling often poorly reflects phylogenetic diversity and is often also biased to represent deeper (family-level) evolutionary relationships.     

New species of parasitoid wasps of the family Eurytomidae (Hymenoptera, Chalcidoidea) from the United Arab Emirates

Two new species of the genus Eurytoma, Eu. emirata Zerova, sp. n. and Eu. cornutella Zerova, sp. n., and two new species of the genus Nikanoria, N. globosa Zerova, sp. n. and N. cuspidata Zerova, sp. n., are described from the United Arab Emirates. This is the first record of genera and species of Eurytomidae from the United Arab Emirates. Holotypes and paratypes of the new species are deposited in the collection of Institute of Zoology, the National Academy of Sciences of Ukraine (Kiev).     

虱目裂化线粒体基因组研究进展

虱目是哺乳类和鸟类体表的专性寄生虫。在虱科、阴虱科、长角鸟虱科和兽羽虱科的某些寄生虱种中发现了线粒体基因组裂化现象, 其线粒体基因组裂化成了多个环状的线粒体染色体, 如体虱(Pediculus humanus)、头虱(pediculus capitis)和阴虱(Pthirus pubis)的线粒体基因组分别裂化形成20个、20个和14个微环染色体。微环染色体可能是基因删除和同源重组的结果, 关于线粒体基因组裂化的具体原因和机制, 目前并不清楚, 推测可能是进化选择或随机遗传漂变的结果或与线粒体单链DNA结合蛋白的缺失有关。鉴于线粒体基因组裂化研究对于深入理解线粒体的起源和进化方面具有重要意义, 文章以虱目裂化线粒体基因组为主线, 列举了动物裂化线粒体基因组和裂化特征, 阐述了虱目裂化线粒体基因组的研究现状, 分析了虱目线粒体基因组裂化的类型、原因和机制, 并对该领域未来的研究方向进行了展望。     

Chalcidoid wasps (Hymenoptera,Chalcidoidea) parasitizing on coccids in Vietnam. XI. A new species of the genus <Emphasis Type="Italic">Coccophagus</Emphasis> westwood (Hymenoptera,Aphelinidae)

Coccophagus thanhoaensis sp. n. is described; it differs from the closely related C. tschirchii Mahdihassan in the following characters: mandibles with two teeth and undulate truncation; anterior part of mesoscutum with V-shaped blackish spot; middle coxae blackish; abdomen moderately pointed at apex.