Web-spinning sawflies of the sylvaticus-group of Pamphilius (Hymenoptera: Pamphiliidae)

Abstract The Pamphilius sylvaticus group is redefined to include seventeen species in the Holarctic: sylvaticus (Linnaeus), fumipennis (Curtis) and nemorum (Gmelin) from Europe; alnicola Ermolenko, daisenus Takeuchi, volatilis (Smith), benesi sp.n., gracilis sp.n., japoni-cus sp.n. and montanus sp.n. from northeastern Asia (mainly Japan); burquei (Provancher), cinctus Harrington, middlekauffi Shinohara & Smith, ocreatus (Say), rileyi (Cresson) and semicinctus (Norton) from eastern N. America; and persicum MacGillivray from eastern N. America and the Caucasus. Each species is described and figured and a key for identification is given.     

Revision of the Australasian genus Orussobaius Benson (Hymenoptera: Symphyta: Orussidae)

Abstract The Australasian genus Orussobaius Benson is revised. Seven species are recognised: Orussobaius paniculus sp. n. from Papua New Guinea, and six species from Australia: O. badius sp. n., O. caligneus sp. n., O. mesembrinus Benson, O. minutissimus sp. n., O. minutus Benson, and O. wilsoni Benson. Orussobaius normani Rayment (new synonymy) is removed from synonymy with O. wilsoni and treated as a junior synonym of O. minutus instead. With a body length of only 2 mm, O. minutissimus sp. n. is the smallest currently known sawfly species in the world. A key is provided and distribution maps are shown for all species. The genus Orussobaius is redefined on the basis of all species currently included.     

Tachinid (Diptera, Tachinidae) parasitoids of sawflies (Hymenoptera, Symphyta)

A list of 31 genera of tachinid parasitoids of sawflies is given. Despite the ecological and habitual similarity of sawflies and Lepidoptera, utilization of sawflies by tachinids was not as successful from the evolutionary point of view as utilization of Lepidoptera. Parasitism of tachinids in sawflies is evidently secondary; it appeared repeatedly and originates from parasitism in Lepidoptera. Most genera of tachinids are polyphagous. Endoparasitic Hymenoptera are koinobionts similarly to tachinids. The direct contact of the parasitoid with active mobile host larva not only results in complication of behavior and its specialization, but also promotes formation of different morphological innovations faster than that in idiobionts.     

Giant sawflies and their kin: morphological phylogeny of Cimbicidae (Hymenoptera)

The Cimbicidae is a small family including the largest extant true sawflies (Tenthredinoidea). It comprises four subfamilies, three of which have a northern hemisphere distribution (Abiinae, Cimbicinae – Holarctic/Oriental; Corynidinae – Palaearctic), whereas the Pachylostictinae are restricted to South America. No previous attempts have been made to evaluate the subfamily classification in a cladistic context. In the present paper, 144 morphological characters from the adult anatomy for a total of 95 species of Cimbicidae and 26 outgroup taxa are scored. All subfamilies and all genera of Cimbicidae except one are represented; all families of Tenthredinoidea are represented in the outgroup. Equal weights (EW) and implied weights (IW) analyses are conducted in tnt . The results largely corroborate the existing subfamily classification, except for Pachylostictinae which are paraphyletic in IW analyses with low K‐values. Abiinae + Cimbicinae is always retrieved and strongly supported; Corynidinae + Pachylostictinae is retrieved in most analyses but weakly supported. Revised diagnoses of the subfamilies are provided. Several genera are retrieved as monophyletic, notable exceptions being Praia and Trichiosoma, which are polyphyletic. The evolution of large body size in Cimbicidae is briefly discussed; possible related phenomena are intrasexual competition and mimicry, i.e. resemblance to large apids or vespids.     

A new genus and a new species of Xiphydriidae (Insecta, Hymenoptera, Symphyta) from India

Heteroxiphia gen. n. (type species: Heteroxiphia maai sp.n.)from India is described and illustrated. This new genus is related to Indoxiphia Maa and Cingalixiphia Maa, from which it is distinguished by the 3-segmented maxillary palps, shape of the claws of the meso- and metalegs, form of forewing vein 2A and the sculpture of the head.     

Sex pheromone perception in male pine sawflies,Neodiprion sertifer (Hymenoptera; Diprionidae)

Summary Electroantennographic and single sensillum recordings were performed on male pine sawfly, Neodiprion sertifer, antennae. Responses to the sex pheromone component (2S, 3S, 7S)- 3,7-dimethyl-2-pentadecenyl (diprionyl) acetate (SSS:OAc), to the behavioral inhibitor (2S, 3R, 7R)-diprionyl acetate (SRR:OAc), to the six other enantiomers of diprionyl acetate, and to the biosynthetic precursor diprionol were recorded. Responses to trans-perillenal, a monoterpene identified in female gland extracts and to (2S, 3S, 7S)-diprionyl propionate (SSS:OPr), a field attractant for N. sertifer and some related sawfly species were also recorded.EAG recordings demonstrated a high antennal sensitivity to SSS:OAc and to SSS:OPr. A somewhat lower response was elicited by SRR:OAc.Single sensillum recordings revealed 8–12 different cells firing in each sensillum, corresponding to the number of cells observed in earlier morphological investigations. Out of these cells all, except one, responded to SSS:OAc and to SSS:OPr. No differences in the response to the two components could be observed. The largest amplitude cell in each sensillum was specifically tuned to the behavioral antagonist, SRR:OAc. The pheromone perception system encountered in male pine sawflies thus differs clearly from that observed in moths.Abbreviation EAG electroantennogram - OAc acetate - OPr propionate     

An intracellular symbiont and other microbiota associated with field-collected populations of sawflies (Hymenoptera: Symphyta)

Six species of sawfly (Hymenoptera: Symphyta) from four taxonomic families (Agridae, Diprionidae, Pamphiliidae, and Tenthredinidae) were collected from locations across Canada and surveyed for their associated microbiota. Total DNA was extracted from individual insects, and polymerase chain reaction (PCR) was used to amplify the conserved 16S rRNA gene from microbiota. Denaturing gradient gel electrophoresis (DGGE) and restriction fragment length polymorphism (RFLP) were undertaken to separate bacterial clones associated with the host insect. Sequencing of the PCR-DGGE and PCR-RFLP products revealed a dominance of alpha- and gamma-Proteobacteria, with most sequences showing high similarity to bacteria previously identified from other insect species and environmental samples. Additionally, a strain of the bacterial endosymbiont Wolbachia and a Wolbachia bacteriophage were identified from the mountain ash sawfly (Pristiphora geniculata).     

Mitonuclear discordance is caused by rampant mitochondrial introgression in Neodiprion (Hymenoptera: Diprionidae) sawflies

We investigate the pervasiveness of hybridization and mitochondrial introgression in Neodiprion Rohwer (Hymenoptera; Diprionidae), a Holarctic genus of conifer-feeding sawflies. A phylogenetic analysis of the lecontei species group revealed extensive discordance between a contiguous mitochondrial region spanning three genes (COI, tRNA-leucine, and COII) and three nuclear loci (EF1alpha, CAD, and an anonymous nuclear locus). Bayesian tests of monophyly and Shimodaira-Hasegawa (SH) tests of topological congruence were consistent with mitochondrial introgression; however, these patterns could also be explained by lineage sorting (i.e., deep coalescence). Therefore, to explicitly test the mitochondrial introgression hypothesis, we used a novel application of coalescent-based isolation with migration (IM) models to measure interspecific gene flow at each locus. In support of our hypothesis, mitochondrial gene flow was consistently higher than nuclear gene flow across 120 pairwise species comparisons (P < 1 x 10(-12)). We combine phylogenetic and coalescent evidence to identify likely cases of recent and ancient introgression in Neodiprion, and based on these observations, we hypothesize that shared hosts and/or pheromones facilitate hybridization, whereas disparate abundances between hybridizing species promote mitochondrial introgression. Our results carry implications for phylogenetic analysis, and we advocate the separation of high and low gene flow regions to inform analyses of hybridization and speciational history, respectively.     

Seasonal flight activity of sawflies (Hymenoptera, Symphyta) in submontane region of the Western Carpathians, Central Slovakia

Species representation and seasonality of adult sawflies (Symphyta) were studied using Malaise traps at three submontane study sites (Hriňová — HR, Mošovce — MO and Štefanová — ŠT) in the Western Carpathians (Central Slovakia). One trap was operated at each study site continuously during the growing season, in MO in 1992, in HR in 1995 and in ŠT in 1996. A total of 9,281 adults representing 244 species in 9 families were collected. Very rich sawfly assemblages were found. The highest species richness was in MO (181 species), followed by ŠT (153 species) and HR (118 species). Pseudodineura fuscula was recorded from Slovakia for the first time. Adults were present in traps from the end of April through the first half of October. Most species occurred from the second half of May through the first half of June and finished flight activity by the end of June. Seasonal flight activities of the 16 most abundant species are analysed and discussed.     

Host plant adaptations in myrtaceous-feeding Pergid sawflies: essential oils and the morphology and behaviour of Pergagrapta larvae (Hymenoptera, Symphyta, Pergidae)

Australian pergine sawflies typically feed on eucalypts and other closely-related Myrtaceae, which are known for their high content of essential oils. We describe a novel morphological adaptation of the inner mandibular surface of larval stage Pergagrapta species, which feed on leaves of Melaleuca quinquenervia (Myrtaceae). This 'scopa mandibularis' forms an extensive mesh of setaceous papillae on what is usually the grinding surface of the mandible. Behavioural, chemical and morphological investigations of the sawfly- Melaleuca system suggest that the scopa may function in the physical separation of toxic leaf oils from the diet. The oils are stored in a pharyngeal diverticulum from where they are ejected under two circumstances. Oil from the diverticulum is voided prior to feeding and/or during feeding at night, which indicates a mechanism to eliminate host-associated oils. Larvae rest in close aggregations during the day, when they retain a full diverticulum, but the oils may be emitted for defensive purposes when larvae are disturbed. Chemical evidence suggests that 1,8-cineole, the major component in the M. quinquenervia leaves, is selectively metabolized to a more soluble hydroxycineole. We postulate that the separation and regurgitation of oils is not only a defence mechanism against predators, as usually stated, but also a mechanism by which pergid larvae eliminate oils from their diet, to reduce the toxicity of their food plants.     

中国吉松叶蜂属一新种记述（膜翅目：松叶蜂科）

记述采自陕西秦岭的吉松叶蜂属Gilpinia Benson1新种－青扦吉松叶蜂G.wilsonae sp.n。该种昆虫青扦Picea wilsonii Mast.，一年发生两代，结茧过冬。新种的模式标本保存于西北林学院昆虫标本室。     

A Neoaplectanid nematode in the larch sawfly Cephalcia lariciphila (Hymenoptera: Pamphiliidae)

A nematode parasitic on prepupae of larch sawfly (Cephalcia lariciphila) appears to be indistinguishable from Neoaplectana carpocapsae. Of three temperatures tested the optimum for development was 25 °C at which most eggs were produced in both the first and second generations. Infective nematodes entered sawfly prepupae through the anus and mouth, but the preferred mode of entry was through the spiracles; prepupal hosts were extremely attractive to infective nematodes. Nematodes overwintered in prepupal hosts and in the soil. Dauerlarvae penetrated 10 cm of packed moist soil to infect prepupae constrained at the bottom of a vertical tube, sawfly mortality decreasing with depth. Dauerlarvae may also migrate 8 cm horizontally, and 5 cm upwards, to invade the host. It is suggested that the nematode could be used to supplement biological control of Cephalcia lariciphila.     

A technique for artificially culturing ichneumonid parasites of woodwasps (Hymenoptera: Siricidae)

Oviposition under artificial conditions was readily induced in the primary parasites Rhyssa persuasoria and R. amoena and the cleptoparasite Pseudorhyssa sternata, ichneumonid ectoparasites of the larvae of siricid woodwasps.A method of rearing their immature stages on natural and substitute hosts is described.

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Zusammenfassung Rhyssa persuasoria und R. amoena, primäre Ektoparasiten der Larven und Puppen von Holzwespen der Familie Siricidae, werden zum Eiablageverhalten angeregt, wenn sie entweder aus Holzwespengalerien entnommenem Fraß oder einer Kultur der symbiotischen Pilze der Siriciden (Amylosterum spp.) ausgesetzt sind. Wirtslarven sind gewöhnlich für die Anregung zur Eiablage erforderlich. Der Kleptoparasit Pseudorhyssa sternata führt seine Legeröhre in die schon von Rhyssa spp. gebohrten Eiablagelöcher, und legt sein Ei in die Nähe des Eies oder der Junglarve des primärparasiten.Siriciden-Wirtslarven kamen auf eine nasse Fraßschicht in mit Papier zugedeckten, auf einer Perspex-Scheibe gedrillten Hohlräumen, wo sie zunächst legereifen Weibchen von Rhyssa spp. ausgesetzt wurden. Die Parasiten wurden von den Hohlräumen angelockt, bohrten in diese ein und legten ihre Eier auf die Wirtslarve oder den umliegenden Fraß ab. P. sternata-Weibchen wurden angelockt, entweder von Hohlräumen, worin die Primärparasiten gleichzeitig bohrten, oder von dem schon vorher von Rhyssa spp. durchbohrten Papier, und legten ihre Eier im Hohlraum ab. P. sternata kommt zur Eiablage, selbst wenn keine Siriciden-Larve und kein unreifes Stadium des Primärparasiten vorhanden sind.Parasiteneier und Wirtsstadien wurden in Zuchtkammern gesetzt, die es erlaubten, Beobachtungen über Verhalten und Entwicklung der Parasiten zu machen. Larven und Vorpuppen von Honigbienen konnten mit Erfolg als Ersatzwirte benutzt werden, sowohl für das Erhalten der Parasiteneiablage als auch für die Zucht der Parasitenlarven. Das weist auf die Möglichkeit einer Massenzucht von Ichneumoniden-Parasiten der Holzwespen unter künstlichen Bedingungen hin.Einige Anwendungen der Eiablage- und Zuchtverfahren werden angeführt.

     

中国细锤角叶蜂属一新种(膜翅目:锤角叶蜂科)

记述了采自中国河南省伏牛山区的锤角叶蜂科Cimbicidae细锤角叶蜂属Leptocimbex1新种:愈节细锤角叶蜂Leptocimbex zhongi Wei,sp.nov.。该新种与L.terrifica Malaise,1931近似,但触角第6~7节几乎愈合,界限模糊,触角窝上突不互相靠近,侧额脊前半部明显,后半部缺如,单眼后区后部黄褐色,翅基片、腹部第2~3背板全部和后足股节全部黑色,阳茎瓣背突叶短宽,端部圆钝等,容易鉴别。新种模式标本保存于中南林业科技大学模式昆虫标本室。     

短痣茎蜂属一新种记述(膜翅目:茎蜂科)

记述采自甘肃天水杏树Prunus armeniaca L.上的短痣茎蜂属1新种:杏短痣茎蜂Stigmatijanus armeniacae Wu,sp.nov.。模式标本保存于天水市秦州区森林病虫害防治检疫站标本室。     

Potrerilloxyela menendezi gen. et sp. nov. from the Late Triassic of Argentina: The oldest representative of Xyelidae (Hymenoptera: Symphyta) for Americas

Potrerilloxyela menendezi gen. et sp. nov. from the Potrerillos Formation, Cuyo Basin, early Upper Triassic, Mendoza Province, Argentina is described. It is included in the living family Xyelidae and tentatively placed in Liadoxyelini of Xyelinae, which is otherwise known only from the Jurassic of Asia. This record is the first for Hymenoptera in the Triassic of the New World and provides new evidence about the close faunal connections between Laurasia and Gondwana during Mesozoic times. The phylogenetic position of the new genus is discussed.     

Parasitism of the Wheat Stem Sawfly (Hymenoptera: Cephidae) in Montana

The wheat stem sawfly,Cephus cinctusNorton (Hymenoptera: Cephidae) was first found in wild grasses and soon became an economically important pest of wheat after cultivation began in the northern Great Plains. Of the species of parasitoids that attackC. cinctusin wild grasses, onlyBracon cephi(Gahan) andB. lissogasterMuesebeck (Hymenoptera: Braconidae) have been found in wheat. Levels of parasitism vary between wheat-producing regions in Montana. Parasitism levels were increased by releasing individuals from a region with high levels of parasitism into a region where parasitism levels were low. This suggests that there has been unequal rates of parasitoid adaptation from wild grasses to wheat in different regions of Montana.