Flies (Diptera) Associated with <Emphasis Type="Italic">Polygraphus proximus</Emphasis> Blandford, 1894 (Coleoptera,Curculionidae) in Siberia and the Russian Far East

The faunal composition of Diptera (Insecta) inhabiting the galleries of Polygraphus proximus over the territory of Siberia and the Russian Far East was studied. As a result, 14 species of Diptera were discovered representing 8 families. Within its secondary range, the invasive beetle P. proximus Blandford, 1894 is affected not only by the well-known introduced species Medetera penicillata Negrobov, 1970 but also by numerous other widespread predatory flies, such as Medetera excellens Frey, 1909, M. pinicola Kowarz, 1877, Xylophagus cinctus (De Geer, 1776), and Toxoneura ephippium (Zettersted, 1860). Four predatory fly species, M. penicillata, M. signaticornis Loew, 1857, Lonchaea bukowskii Czerny, 1934, and Xylophagus sachalinensis (Pleske, 1925), affect P. proximus within its native range in the Russian Far East. Data on the predation of each species of Diptera on several species of bark beetles testify to their polyphagy. Saprophagous larvae of Dicranomyia modesta (Meigen, 1818), Chalcosyrphus piger (Fabricius, 1794), Xylosciara lignicola (Winnertz, 1867), and Pseudolycoriella unispina (Mohrig et Krivosheina, 1983) were discovered in bark beetle galleries for the first time.     

Olfactometric evidence for aggregation pheromone production by females of the four-eyed fir bark beetle <Emphasis Type="Italic">Polygraphus proximus</Emphasis> Blandf. (Coleoptera,Curculionidae: Scolytinae)

Chemical communication of the four-eyed fir bark beetle Polygraphus proximus Blandf., an aggressive invasive pest of the Siberian fir Abies sibirica Ledeb., was experimentally studied using a four-way olfactometer of a modified design, in which the tested insects were allowed to move on their own from a lightproof plastic container onto the lighted arena. Young hibernated adults of P. proximus were offered four variants of odor: fir log segments infested with (1) 10 males, (2) 10 females, (3) 10 couples of P. proximus, and (4) clean air as the control. The pheromone of P. proximus was shown to be produced by females; a similar response of both sexes characterized it as an aggregation pheromone. All the three variants with infested fir logs were much more attractive than the control variant with clean air. Volatiles from fir tissues not only seem to serve as markers facilitating host selection by the first-to-arrive beetles before direct contact with the tree bark, but also to be used as pheromone precursors or synergists. The absence of difference in response to the logs infested with males and couples of the bark beetle indicated that pheromone synthesis was inhibited after couple formation.     

Additions to the check list of bark beetles (Coleoptera,Curculionidae: Scolytinae) from Leningrad Province,Russia

The field work of the authors during the last 16 years in both the western and the eastern parts of Leningrad Province, Russia, has resulted in the addition of 7 species to the regional list of bark beetles, namely: Hylurgus ligniperda F., Crypturgus subcribrosus Egg., Pityogenes irkutensis Egg., Scolytus mali Bechst., S. scolytus F., S. pygmaeus F., and Xyleborinus attenuatus Blandf. Of these species, P. irkutensis occurs only in the eastern districts of Leningrad Province, C. subcribrosus, over the whole territory, and the remaining species, only in the western districts. We suggest excluding Polygraphus proximus Blandf. from the regional faunal list. As a result, the updated list of the bark beetle species of Leningrad Province comprises 75 taxa. New data on findings of rare species in the region are considered.     

Description of the stridulatory apparatus of the Far Eastern bark beetles <Emphasis Type="Italic">Polygraphus proximus</Emphasis> Blandford, 1894 and <Emphasis Type="Italic">P. jezoensis</Emphasis> Niisima, 1909 (Coleoptera,Curculionidae: Scolytinae)

The stridulatory organ structure in two Far Eastern bark beetles, Polygraphus proximus and P. jezoensis, is described. The elytro-tergal type of the stridulatory apparatus is found in P. jezoensis. The structure involved in acoustic communication of P. jezoensis is present only in males. The plectrum of P. proximus males is re-described. Similarly to that in P. jezoensis, it is formed by two tubercles at the distal margin of tergite VII. An additional type of stridulatory organ used for the producing of precopulatory courtship signals is described for males of P. proximus. In this type of stridulatory organ, transverse ridges on the costal margin of the elytron act as pars stridens, and the hind tibia, as the plectrum.     

Taxonomy and pathogenicity of <Emphasis Type="Italic">Leptographium</Emphasis> species associated with <Emphasis Type="Italic">Ips subelongatus</Emphasis> infestations of <Emphasis Type="Italic">Larix</Emphasis> spp. in northern China,including two new species

The larch bark beetle (Ips subelongatus), which occurs in larch plantations over a vast area of eastern Asia, infects both dying and fallen trees. When its population reaches a high density, the beetle may also infect healthy trees, resulting in tree decline and, eventually, death. Leptographium spp., in both their sexual and asexual states, are mainly associated with conifer-infesting bark beetles; some species are important tree pathogens. The aims of this study were to identify the Leptographium spp. associated with I. subelongatus infestations of Larix spp. in northern China and to examine their pathogenicity towards the tree. Morphological studies and phylogenetic approaches based on multilocus DNA sequence data (ITS2- partial r28S, partial β-tubulin, and EF-1α gene regions) showed that three Leptographium species occur in association with I. subelongatus in the areas investigated: Leptographium taigense, which is recorded in China for the first time, and two new species, namely L. innermongolicum sp. nov. and L. zhangii sp. nov. Leptographium innermongolicum is closely related to L. taigense, whereas L. zhangii belongs to the Grosmannia piceaperda species complex. The pathogenicity of these Leptographium species towards mature Larix spp. was tested by stem inoculation in forests. All inoculations only resulted in small lesions on the inner bark; therefore, the three Leptographium species were not considered to be pathogenic.     

Migration of the Northern Boundary of the Siberian Silk Moth

Climate changes have induced the northward migration of outbreaks of the Siberian silk moth (Dendrolimus sibiricus Tschetv.), one of the most dangerous pests in the taiga. The initial outbreak of the Siberian silk moth began in 2014 in Siberian pine.fir stands within the Yenisei Plain on the southwestern flat slopes at elevations up to 200 m above sea level. Further, the outbreak extended to the parts of the forest with higher humidity, the northern slopes, and Yenisei Ridge at low and middle elevations. The northern limit of the outbreak zone shifted to 50 km (to 60°26′ N) northward from the historical boundary of formerly observed outbreaks. The outbreak was incited by an increase in aridity, the sum of positive temperatures (t > +10°C), and a decrease in soil moisture. It extended to an area of 800000 ha. Stand mortality was accompanied by the activation of secondary pests, including aggressive bark beetle species Polygraphus proximus. The outbreak under study is part of the panzonal outbreak that occurred in 2014–2017 on the territory of Siberia in Krasnoyarsk krai and Tomsk, Kemerovo, and Irkutsk oblasts. The increase in warming, aridity, and vegetative period provides opportunities for the Siberian silk moth to migrate to the northern dark-conifer taiga.     

Dynamic associations between <Emphasis Type="Italic">Ips sexdentatus</Emphasis> (Coleoptera: Scolytinae) and its phoretic mites in a <Emphasis Type="Italic">Pinus pinaster</Emphasis> forest in northwest Spain

The relationship between the pine bark beetle Ips sexdentatus and its phoretic mites in a Pinus pinaster forest in northwest Spain was studied during 2014. Four species of mites were collected, three of them from the body of the beetle—Histiostoma ovalis, Dendrolaelaps quadrisetus and Trichouropoda polytricha—the fourth, Cercoleipus coelonotus, was collected from the sediments. The main aims of this study were to explore (1) mite diversity and related parameters, (2) the location on the body of the (male and female) beetle, as well as mite assemblages, and (3) the seasonal dynamic association between mite species and the beetle. Results indicated that the diversity oscillated around 0.71 through the study period and the most dominant, frequent and abundant mite was H. ovalis. Histiostoma ovalis was found attached to almost all parts of the body (mainly on the elytral declivity and ventral thorax), whereas D. quadrisetus was exclusively found under the elytra, and T. polytricha displayed affinity towards the elytral declivity as well as the ventral thorax. None of the mite species displayed any preference for the sex of the beetle and the most frequent mite assemblage was H. ovalis, T. polytricha and D. quadrisetus all together. Maximum abundance of each phoretic mite species was related with each of the flight peaks of the beetle that would indicate that these mite species use phoresy as a primary method of transport for colonizing new food sources.     

Gene pool state and degree of infestation by bark beetle (<Emphasis Type="Italic">Ips tipographus</Emphasis> L.) of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> L. Karst.) natural populations and planted stands in Moscow region

A comparative analysis of the gene pool state in natural populations and planted stands of Norway spruce and the degree of their infestation by the bark beetle in the Moscow region was conducted taking into account the dynamic state of communities (4 populations, 148 samples, 24 isoenzyme loci). The degree of infestation by the bark beetle of conditionally native communities is 0%; for planted stands, it is 90–100%; and for a short-term community, it is 15–20%. The comparison of “healthy” populations and those infested with bark beetle by average values of observed heterozygosity (H _O) detected no significant differences. However, the test on allelic frequency heterogeneity demonstrated the difference of planted stands from conditionally native populations both by three loci (Fe-2, Idh-1, Mdh-3) and by the totality of 18 polymorphic isoenzyme loci; the short-term population differs from conditionally native population only by two loci. The value of the inbreeding coefficient by the Idh-1 locus is significantly higher in both populations infested with the bark beetle than in “healthy” populations. The results of conducted studies demonstrate the necessity of continuation of the study on the gene pool state in Norway spruce populations owing to the degree of their infestation by the bark beetle along with the study on the dynamic state of the communities; this can provide a key to solving the problem of the forest preservation from pests.     

The fungal matrices of <Emphasis Type="Italic">Ophiostoma ips</Emphasis> hinder movement of the biocontrol nematode agent, <Emphasis Type="Italic">Deladenus siricidicola</Emphasis>, disrupting management of the woodwasp, <Emphasis Type="Italic">Sirex noctilio</Emphasis>

Deladenus (=?Beddingia) siricidicola (Tylenchida: Neotylenchidae) is the most effective biocontrol agent used against the invasive wood wasp, Sirex noctilio (Fabricius) (Hymenoptera: Siricidae). The nematodes feed and reproduce on the wood-inhabiting fungus, Amylostereum areolatum (Chaillet ex Fr.) Boidin (Russulales: Amylostereaceae) and parasitise larvae of S. noctilio. In the nematode biocontrol program, the nematodes are inoculated into herbicide-weakened ‘trap trees’. Recent declines in nematode parasitism of S. noctilio in Australia have coincided with an increased incidence of an exotic bark beetle, Ips grandicollis (Eichhoff) (Coleoptera: Curculionidae), attacking trap trees and vectoring a wood-inhabiting fungus, Ophiostoma ips (Rumbold) Nannfelt (Ophiostomatales: Ophiostomataceae), which may inhibit migration of the nematode within the tree to the detriment of S. noctilio biocontrol. Several in vitro and in vivo experiments were conducted to investigate the effect of fungal interactions on the ability of D. siricidicola to locate and reproduce on A. areolatum. Deladenus siricidicola showed preference to A. areolatum in the presence and absence of O. ips, but the presence of O. ips negatively affected the choice response and the number of eggs laid by the nematodes. Deladenus siricidicola was unable to survive and reproduce on O. ips. Results give a clearer understanding of the choice response of D. siricidicola in I. grandicollis infested trees, explaining the disruptive impact of bark beetles on biocontrol of S. noctilio, an effect that could extend from Australia to other important pine growing countries.     

Coleoptera associated with <Emphasis Type="Italic">Fomitopsis pinicola</Emphasis> (Sw.:Fr.) Karst. (Basidiomycetes,Aphyllophorales) in the forests of the Urals and Transurals

A detailed characteristic of the beetle fauna associated with Fomitopsis pinicola (Sw.: Fr.) Karst. (Basidiomycetes, Aphyllophorales) in the Urals and Transurals is given. Thirty species from 14 families have been revealed, the commonest species including Eridaulus jacquemarti Mel., Ennearthron laricinum (Mel.) (Ciidae), Dorcatoma dresdensis Hbst., D. lomnickii Rtt., D. punctulata Muls. (Anobiidae), Diaperis boleti (L.) (Tenebrionidae), Scaphisoma agaricinum (L.), S. inopinatum Löbl, S. subalpinum Rtt. (Scaphidiidae), Ostoma ferruginea (L.), and Peltis grossa (L.) (Peltidae). The main trends in the ecological and trophic specialization of mycetophilous beetles are discussed, and some regularities of formation of mycetophilous complexes at different stages of the trees fungi fruit body development are revealed.     

<Emphasis Type="Italic">Hexamermis popilliae</Emphasis> n. sp. (Nematoda: Mermithidae) parasitizing the Japanese beetle <Emphasis Type="Italic">Popillia japonica</Emphasis> Newman (Coleoptera: Scarabaeidae) in Italy

A new species of mermithid nematode, Hexamermis popilliae n. sp. (Nematoda: Mermithidae) is described from the Japanese beetle Popillia japonica Newman in Italy, an area of new introduction for this invasive pest. The combination of the following characters separates H. popilliae from other members of the genus Hexamermis Steiner, 1924: adult head obtuse; amphidial pouches slightly posterior to lateral head papillae in female but adjacent to lateral head papillae in males; amphidial openings large, well developed; amphidial pouches elliptical in females and oblong in males; cuticular vulvar cone well developed, vulvar lips greatly reduced or lacking, vagina curved at tip where meeting uteri, without reverse bend (not S-shaped), spicules slightly curved, with a slight bend in the basal portion, approximately equal to body width at cloaca. This is the first record of a species of Hexamermis parasitizing the Japanese beetle Popillia japonica. The only previous mention of mermithid nematodes from P. japonica was an undescribed species of Psammomermis in North America. Hexamermis popilliae will be evaluated as a potential biological control agent in an integrated control program of the Japanese beetle in Italy.     

<Emphasis Type="Italic">Metarhizium bibionidarum</Emphasis> and <Emphasis Type="Italic">M. purpureogenum</Emphasis>: new species from Japan

Two new species of Metarhizium, M. bibionidarum and M. purpureogenum are described from Japan. Metarhizium bibionidarum is the phylogenetic sister species of M. pemphigi and a member of the M. flavoviride species complex. It is distinguished morphologically from M. pemphigi by its larger conidia. The species is based on a collection of an infected March fly larva (Diptera: Bibionidae) but is also known to occur on fruit beetle (Coleoptera: Scarabaeidae) encountered in France. Metarhizium purpureogenum was isolated from soil by plating and insect baiting methods and represents a unique phylogenetic lineage placed outside the M. anisopliae and M. flavoviride species complexes. Three isolates of M. purpureogenum excreted a distinctive red-purple pigment into agar medium when co-cultured with M. robertsii or Aspergillus oryzae.     

The Structure and Density of Aggregations of the Hermit Crab <Emphasis Type="Italic">Pagurus proximus</Emphasis> Komai, 2000 in Epibiosis of the Brown Alga <Emphasis Type="Italic">Costaria costata</Emphasis> (C. Agardh) De A. Saunders, 1895 in the Sublittoral Zone of Vostok Bay,Sea of Japan

A study of epibiosis of the brown alga Costaria costata in the sublittoral zone of Vostok Bay, Sea of Japan during the spring and summer of 2016 showed that hermit crabs of the following four species accounted for approximately 85% of the total biomass: Pagurus proximus, P. minutus, P. brachiomastus, and P. middendorffii. Of these, the most abundant one (96.5% of the total number of hermit crabs) was P. proximus, the mean aggregation density of which on C. costata (429 ± 221 ind./m²) was higher by an order of magnitude than that in the adjacent area of the bouldery bottom. The size ranges of males and females of this species in aggregations on boulders and those on C. costata were similar, with a predominance of larger individuals on algae. In the size–frequency distribution, three groups of individuals corresponding to three size–age cohorts were differentiated. The male-to-female ratio was 1 : 1.7. Hermit crab aggregations on C. costata are ephemeral; their existence is determined by the duration of the period of algae development, that is, from late spring to the middle of the summer.     

Environmental risk assessment of the egg parasitoid <Emphasis Type="Italic">Anaphes inexpectatus</Emphasis> for classical biological control of the <Emphasis Type="Italic">Eucalyptus</Emphasis> snout beetle, <Emphasis Type="Italic">Gonipterus platensis</Emphasis>

Classical biological control is a valuable tool against invasive pests, but concerns about non-target effects requires risk assessment studies. Potential non-target effects of Anaphes inexpectatus Huber and Prinsloo (Hymenoptera: Mymaridae) were assessed for a classical biological control programme against the Eucalyptus snout beetle, Gonipterus platensis (Marelli) (Coleoptera: Curculionidae). No-choice tests were conducted with 17 non-target species to assess host specificity, including 11 curculionids. In behavioural observations, A. inexpectatus showed no interest in any of the non-target species, but two weevil species were parasitised within five days of exposure, although at significantly lower rates than G. platensis. In choice tests, only one non-target, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), was parasitised, at a rate of 0.6%, while 50.0% of G. platensis eggs were parasitised. Based on the host specificity test results and the potential host fauna found in the target area, the likelihood of non-target effects resulting from the release of A. inexpectatus is considered to be negligible.     

Updates on East Asian <Emphasis Type="Italic">Asterostroma</Emphasis> (Russulales,Basidiomycota): new species and new records from Thailand and China

Two new species from northern Thailand, Asterostroma bambusicola and A. vararioides, are described and illustrated. Asterostroma bambusicola is characterized by globose, echinulate, and amyloid basidiospores and growing on rotten bamboo. Asterostroma vararioides is distinguished by the presence of Vararia-like dichohyphae, subglobose, smooth, and amyloid basidiospores and growing on bark of living angiosperm trees. In the phylogenetic tree inferred from a combined dataset of ITS and nLSU sequence data of Peniophoraceae, A. bambusicola forms a distinct lineage in the sect. Asterostroma clade, whereas A. vararioides and A. laxum form the sect. Laevispora clade. Asterostroma andinum, reported from China for the first time, forms a distinct lineage sister to Gloiothele spp. and Scytinostroma portentosum group. Asterostroma muscicola is reported from Thailand and China for the first time. A key to the species of Asterostroma from Thailand and China is provided.     

The species composition and pattern of distribution of hermit crabs (Decapoda: Paguroidea) in Vostok Bay,Sea of Japan

The species composition, abundance, and vertical distribution of hermit crabs (Decapoda: Paguroidea) were investigated in Vostok Bay, Sea of Japan, from September 2014 to September 2015. A total of seven species from two families were found in the monitoring area of approximately 5000 m² located on the bottom within a depth range of 0–11 m: Pagurus minutus, P. proximus, P. brachiomastus, P. pectinatus, P. ochotensis, P. middendorffii (Paguridae), and Areopaguristes hirsutimanus (Diogenidae). Their population density varied from 22 ± 13 to 26 ± 2 ind./m²; the biomass varied from 55.76 ± 26.10 to 93.38 ± 27.00 g/m². The species composition remained invariable throughout the study period. The proportions of species abundance changed between seasons, as this parameter is largely determined by seasonal migrations of hermit crabs. Pagurus minutus predominated in number in winter and spring (up to 71%); P. proximus, in summer and autumn (up to 47%). In autumn and spring, P. ochotensis and P. pectinatus constituted a major part of biomass (18–25% and 19–20%, respectively). The proportion of a previously abundant species, P. middendorffii, was very small (no larger than 1.3%) during the study period. Another four species of hermit crabs occurred in other parts of Vostok Bay; thus, the fauna of the bay currently includes 11 species of this group.     

Inter-species interactions and ecosystem effects of non-indigenous invasive and native tree-killing bark beetles

Frequent bark beetle outbreaks cause biome-scale impacts in boreal and temperate forests worldwide. Despite frequent interceptions at ports of entry, the most aggressive bark beetle species of Ips and Dendroctonus in North America and Eurasia have failed to establish outside their original home continents. Our experiments showed that Ips typographus can breed in six North American spruce species: Engelmann spruce, white spruce¸ Sitka spruce, Lutz spruce, black spruce and red spruce. This suggests that differences between the Eurasian historical host and North American spruce species are not an insurmountable barrier to establishment of this tree-killing species in North America. However, slightly diminished quality of offspring beetles emerged from the North American spruces could reduce the chance of establishment through an Allee effect. The probabilistic nature of invasion dynamics suggests that successful establishments can occur when the import practice allows frequent arrivals of non-indigenous bark beetles (increased propagule load). Model simulations of hypothetical interactions of Dendroctonus rufipennis and I. typographus indicated that inter-species facilitations could result in more frequent and severe outbreaks than those caused by I. typographus alone. The potential effects of such new dynamics on coniferous ecosystems may be dramatic and extensive, including major shifts in forest structure and species composition, increased carbon emissions and stream flow, direct and indirect impacts on wildlife and invertebrate communities, and loss of biodiversity.     

Hypocrealean fungi associated with populations of <Emphasis Type="Italic">Ips typographus</Emphasis> in West Carpathians and selection of local <Emphasis Type="Italic">Beauveria</Emphasis> strains for effective bark beetle control

In Slovakia, a diversity of entomopathogenic fungi (Ascomycota, Hypocreales) associated with outbreaks of Ips typographus was studied in 81 localities and as many as 113 in vitro cultures of five entomopathogenic species were isolated from infected individuals: Beauveria bassiana (87 isolates), B. pseudobassiana (14 isolates), B. caledonica (6 isolates), Lecanicillium lecanii (4 isolates) and Isaria farinosa (2 isolates). B. pseudobassiana is recorded in natural populations of I. typographus for the first time. Biological properties of selected Beauveria isolates, including colony growth, biomass production, conidia yield and pathogenicity to I. typographus adults, were studied in a series of laboratory bioassays and much intra- and interspecific variability was detected. B. bassiana isolates produced biomass or conidia at significantly higher rate than B. pseudobassiana and B. caledonica isolates. Two B. bassiana isolates were selected as the most virulent to bark beetle adults, demonstrating a mean LC₅₀ ranging from 0.72 to 2.05?×?10⁶ conidia ml^?1, and were qualified as promising candidates for biocontrol of I. typographus. Their virulence was significantly higher than that of the mycoinsecticides Boverol®, which was used as a reference strain in the virulence bioassays.