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.     

Host plant influence on chemical defense in conifer sawflies (Hymenoptera: Diprionidae)

Host diet affects the defensive efficacy of Neodiprion sawflies. In laboratory assays with wood ants (Formica obscuripes), secretions from larvae reared on Pinus banksiana were the most repellent, while those from P. resinosa feeders were the least so. This was explained diterpene resin acid content, but not total monoterpene content. The terpene content of regurgitant generally reflected dietary concentrations. Compounds were sequestered nonselectively by larvae. Host-based differences in defense persisted at the behavioral level. P. banksiana feeders regurgitated greater volumes of fluid and were less likely to be disabled or killed by ants in one-on-one interactions than were larvae fed on P. resinosa. The defensive advantages of host diet conflicted with developmental requirements. N. sertifer reared on P. banksiana (the best diet for defense in all cases) had lower cocoon weights (a correlate of fecundity) than those reared on other diets, and had prolonged larval development compared to insects fed P. sylvestris. No such tradeoff was detected in N. lecontei. Larvae of both species strongly preferred P. banksiana over P. resinosa in feeding choice assays.     

Structure and mechanical strength of larval cuticle of sawflies capable of "easy bleeding" a defence strategy against predators evolved in Tenthredinidae (Hymenoptera)

The cuticle of Tenthredinidae (Hymenoptera) larvae is ruptured after a very mild mechanical stress and hemolymph is released. This phenomenon, called "easy bleeding" is considered as a defence strategy against predators. We investigated the cuticle structure of some selected species capable of "easy bleeding" by light-, transmission- and scanning microscopy and compared it with phylogenetically-related sawfly species without this defense strategy (control). Cuticle thickness has no major influence on mechanical stability, but pronounced local differences in thickness seem to be inversely correlated with mechanical strength. The density of chitin fibrils is considerably reduced in animals capable of easy bleeding and the fibres form a loose 3D network in contrast to the densely packed layers seen in related "non easy bleeding" species like Strongylogaster multifasciata, where a pressure of 2584 kPa is needed to pierce the integument, and which served as a control. Efficient bleeders like Phymatocera aterrima (203 kPa) and Rhadinoceraea nodicornis (219 kPa) are devoid of any defined layers or other structural elements. In Athalia rosae (Allantinae) (539 kPa), and Aglaostigma discolor (Tenthredininae) (1494 kPa)--bleeders with medium efficiency--a reduced number of layers are observed by LM and TEM and a loose network of chitin fibres is visible after treatment with KOH.     

Morphology of the pretarsus of the sawflies and horntails (Hymenoptera: 'Symphyta')

The pretarsal structures have been studied in representatives of 13 families of 'Symphyta' by means of light microscopy. The pretarsal sclerites (manubrium, planta, and unguitractor) vary in shape among different families. The shape of the manubrium is triangular in representatives of Xyelidae and Orussidae and bifurcated in those of Tenthredinoidea. For representatives of Siricomorpha, an elongated shape of the manubrium is typical with such variations, as distally expanded, proximally expanded, clavate, spear-shaped. Plantae of different Symphyta vary in shape and level of sclerotization. In representatives of Siricidae, the female manubrium and arolium are significantly reduced, and arcus and dorsal plates are completely absent. Siricid males possess all pretarsal sclerites and a well-developed arolium. Auxiliary sclerites are absent in representatives of Orussidae. Trichoid sensilla are absent on the plantae in representatives of Cephidae and Orussidae. Other studied Symphyta possess two trichoid sensilla on the planta. Representatives of all investigated families bear two campaniform sensilla on the manubrium, with the exception of Siricidae having three sensilla. Kinematics of the pretarsus with bifurcated manubrium are modeled and discussed.     

Phylogenetics and reticulate evolution in Pistacia (Anacardiaceae)

The systematic position and intrageneric relationships of the economically important Pistacia species (Anacardiaceae) are controversial. The phylogeny of Pistacia was assessed using five data sets: sequences of nuclear ribosomal ITS, the third intron of the nuclear nitrate reductase gene (NIA-i3), and the plastid ndhF, trnL-F and trnC-trnD. Significant discordance was detected among ITS, NIA-i3, and the combined plastid DNA data sets. ITS, NIA-i3, and the combined plastid data sets were analyzed separately using Bayesian and parsimony methods. Both the ITS and the NIA-i3 data sets resolved the relationships among Pistacia species well; however, these two data sets had significant discordance. The ITS phylogeny best reflects the evolutionary relationships among Pistacia species. Lineage sorting of the NIA-i3 alleles may explain the conflicts between the NIA-i3 and the ITS data sets. The combined analysis of three plastid DNA data sets resolved Pistacia species into three major clades, within which only a few subclades were supported. Pistacia was shown to be monophyletic in all three analyses. The previous intrageneric classification was largely inconsistent with the molecular data. Some Pistacia species appear not to be genealogical species, and evidence for reticulate evolution is presented. Pistacia saportae was shown to be a hybrid with P. lentiscus (maternal) and P. terebinthus (paternal) as the parental taxa.     

The First Record of Endasys liaoningensis (Hymenoptera: Ichneumonidae) Parasitizing on Pachynematus itoi (Hymenoptera: Tenthredinidae) in Korea

An ichneumon species, Endasys liaoningensis Wang et al., is reported for the first time from Korea. Morphological characteristics of adults are redescribed with illustrations. In addition, the biological characteristics and their distributional ranges are discussed.     

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.     

Life history of Aneugmenus merida Smith (Hymenoptera: Tenthredinidae) in the Venezuelan Andes

Details of the life cycle of Aneugmenus merida Smith (Hymenoptera: Tenthredinidae) reared under laboratory conditions are reported. Females may produce parthenogenetic or non-parthenogenetic eggs. After eclosion, males of A. merida go through five larval instars, pre-pupa, pupa and imago. The complete life cycle lasts approximately 44 days. Larvae feed on bracken [Pteridium caudatum (L.) and Pteridium arachnoideum (Kaulf)] (Dennstaedtiaceae). We also report on morphological observations of the sinus sexualis in males by scanning electron micrographs and give details on mating behavior.     

A second species of Tyloceridius Malaise (Hymenoptera,Tenthredinidae)

Tyloceridius Malaise, 1945 and T. dorsatus (Mocsáry, 1883) are redescribed. Tyloceridius stictocephalussp. n. from China and Nepal is described. Tyloceridius is recorded in China for the first time.     

Review of the sawfly genus Empria (Hymenoptera, Tenthredinidae) in Japan

The following eleven Empria species are reported from Japan: Empria candidata (Fallén, 1808), Empria japonica Heidemaa & Prous, 2011, Empria liturata (Gmelin, 1790), Empria loktini Ermolenko, 1971, Empria plana (Jakowlew, 1891), Empria quadrimaculata Takeuchi, 1952, Empria rubicola Ermolenko, 1971, Empria tridens (Konow, 1896), Empria tridentis Lee & Ryu, 1996, Empria honshuana Prous & Heidemaa, sp. n., and Empria takeuchii Prous & Heidemaa, sp. n. The lectotypes of Poecilosoma pallipes Matsumura, 1912, Empria itelmena Malaise, 1931, Tenthredo candidata Fallén, 1808, and Tenthredo (Poecilostoma) hybrida Erichson, 1851 are designated. Empria itelmena Malaise, 1931, syn. n. is synonymized with Empria plana (Jakowlew, 1891). Poecilosoma pallipes Matsumura, 1912, previously assigned to Empria, is transferred to Monsoma, creating Monsoma pallipes (Matsumura, 1912), comb. n. Results of phylogenetic analyses using mitochondrial (COI) and nuclear (ITS1 and ITS2) sequences are also provided.     

中国大跗突瓣叶蜂种团一新种(膜翅目:叶蜂科)

记述采自中国广西、贵州、湖南和浙江境内的突瓣叶蜂属大跗突瓣叶蜂种团1新种:钟氏突瓣叶蜂Nematus zhongi Liu,Li&Wei sp.nov.,编制了大跗突瓣叶蜂种团中国已知种类检索表.     

Life history of Aptesis nigrocincta (Hymenoptera: Ichneumonidae) a cocoon parasitoid of the apple sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidae)

Aptesis nigrocincta: Gravenhorst is a bivoltine ectoparasitoid of apple sawfly cocoons, hosts that must be found and parasitized by females at a depth of 10-25 cm in the soil. Females are significantly smaller than males and nearly wingless. After encountering a host, females needed 29.3 min at 20 degrees C and 19. 9 min at 25 degrees C to deposit an egg on the host. Development from egg to adult took 39.6 days for females and 38.0 days for males at 20 degrees C. This small difference was significant. At 20 degrees C, the longevity of females that had no opportunity to oviposit was on average 72.5 days, significantly higher than male longevity (50.6 days). The longevity of females given access to hosts throughout their lifetime averaged 58.6 days. Females were able to mate immediately after emergence and copulation lasted on average 21.7 s. After a pre-oviposition period averaging 5.8 days, females laid 20.2 eggs during their lifetime, thus less than one egg per day. Neither the fecundity nor longevity of individual females was correlated with body size. If females were deprived of food, longevity as well as lifetime fecundity were drastically reduced. Field studies were carried out in one organically managed apple orchard in Switzerland. Aptesis nigrocincta showed parasitism rates ranging from 12.1 to 39.7 % within single parasitoid generations, thereby constituting the most important mortality factor of apple sawfly cocoons.     

Resistance to the birch leafminer Fenusa pusilla (Hymenoptera: Tenthredinidae) within the genus Betula

Thirteen Betula species were tested for resistance to the birch leafminer, Femusa pusilla (Lepeletier), using no-choice assays. Birch leafminers were able to oviposit into expanding leaves of all Betula individuals tested. Larvae did not survive within any of the tested individuals of three species, B. alleghaniensis (Britt.), B. grossa (S. & Z.), and B. lenta (L.). Leafminer eggs deposited into the leaves of these species hatched, and larvae fed for a short period before dying. These three species were classified as highly resistant to birch leafminer, based on very low percent of mines (0.6-3.1%) with a diameter >3 mm. Eight species, B. papyrifera (Marsh), B. pendula (Roth), B. turkestanica (Litvin), B. glandulifira (Regal), B. ermanii (Cham.), B. platyphylla variety japonica [(Miq.) Hara], B. populifolia (Marsh) and B. maximowicziana (Regal) were classified as susceptible, with percent of mines >3 mm diameter of 87-94%. Two species, B. costata (Trautv.) and B. davurica (Pall.), displayed intermediate and variable resistance. B. davurica exhibited a mechanism of resistance not observed in the other species, Eggs oviposited into the leaves of resistant B. davurica individuals became surrounded by an area of discolored and necrotic tissue, and died. This response resembles the programmed cell death associated with a hypersensitive response.     

Egg Deposition Behavior in the Haplodiploid Sawfly Athalia rosae ruficornis Jakovlev (Hymenoptera: Symphyta: Tenthredinidae)

The egg deposition behavior of the turnip sawfly, Athalia rosae (Hymenoptera: Symphyta), is described. Both unmated and mated females lay eggs individually inside of fresh young leaves of cruciferous plants. During an oviposition event, females exhibit a distinct pause in abdominal contractions just before the actual egg deposition act. Unmated females show a longer pause (11.31 s on average) than mated females (4.38 s on overall average). By employing an eye color mutation, the sex of the eggs laid by females was ascertained. Females mated once lay mostly fertilized (diploid female) eggs initially but begin to lay a considerable number of unfertilized (haploid male) eggs later in life. The laying of an unfertilized egg is associated with a longer pause (6.98 s on average) than the laying of a fertilized egg (3.76 s on average). These results are in contrast to previous reports on apocritan Hymenoptera, where the presence of a pause or a longer pause during oviposition was associated with the deposition of fertilized eggs rather than unfertilized eggs. The possibility that mated Athalia rosae females control fertilization and its implications for sex allocation strategies are discussed.     

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).     

Three new species of sanguinolenta-group of the genus Macrophya(Hymenoptera:Tenthredinidae) from China

Macrophya opacifrontalis Li,Lei Wei,sp.nov.,M.pseudofemorata Li,Wang, Wei,sp.nov.,and M.huangi Li Wei,sp.nov.of the sanguinolenta-gxoup of Macrophya(Hymenoptera:Tenthredinidae) from China are described.M.opacifrontalis and M.pseudofemorata is belong to the tongi-subgroup,whereas M.huangi belongs to the depressinasubgroup.The division of the tongi and depressina subgroups and species inside are briefly discussed.Keys to all known species of the tongi and depressina-subgroups from China are provided respectively.     

An account of the Chalcidoidea (Hymenoptera) parasitising leaf-mining insects of deciduous trees in Britain

Data on the distribution and frequency of hymenopterous parasites of leaf-mining insects on deciduous trees show that Chalcidoidea of the family Eulophidae are the chief component of the parasite faunas. The regular parasite complement of a leaf-mining species is in the order of 10 to 20 species of parasitic Hymenoptera. Many of these are polyphagous, but in almost all instances a preference for a particular type of host is evident. The parasite faunas of tree leaf-mining Lepidoptera, Coleoptera and Hymenoptera are shown to be qualitatively similar, but those of Diptera are rather different. The parasite faunas of tree leaf-miners are different also from those of leaf gall-forming insects on trees and, to a lesser degree, from those of leaf-miners on herbaceous plants. The parasite fauna associated with a tree genus is quantitatively and qualitatively characteristic and, in general, it most resembles that found on allied tree genera. Congeneric leaf miners attacking the same tree species are attacked by very similar parasite faunas, although mine situation and season of development may exert some influence. These latter factors are considered especially in relation to leaf-miners of the genus Phyllonorycter for which most data are available.