Horizontal transmission of a parasitic nematode from a non-native to a native woodwasp?

In eastern North America, the exotic invasive woodwasp, Sirex noctilio, attacks pines (Pinus spp.) and often shares larval habitat with the native woodwasp, Sirex nigricornis. The parasitic nematode, Deladenus siricidicola, has been used widely in the southern hemisphere as a biological control agent because it sterilizes female S. noctilio. This nematode was introduced accidentally to North America along with S. noctilio. Historical reports indicate nematode-woodwasp fidelity: the parasitic nematode, D. siricidicola, exclusively infects S. noctilio, and the native nematode, Deladenus proximus, exclusively infects S. nigricornis. From two sites in southern Ontario, separated by 225 km, we collected woodwasps from three Pinus sylvestris, and identified the nematode species present in the abdomens of infected wasps. Both wasp species co-occurred in all three trees. D. siricidicola was present in the haemocoel, but not inside the eggs, of infected S. noctilio and S. nigricornis. This evidence suggests horizontal transmission of D. siricidicola likely occurred from S. noctilio to S. nigricornis.     

Influence of Nematode Parasitism,Body Size,Temperature, and Diel Period on the Flight Capacity of <Emphasis Type="Italic">Sirex noctilio</Emphasis> F. (Hymenoptera: Siricidae)

Sirex noctilio F. (Hymenoptera: Siricidae) is a woodwasp of pine trees that has recently invaded and established in North American forests. Although S. noctilio has had a limited impact in North America to date, there is some concern that it could have a significant impact on pine plantations, especially in the southeastern U.S.A. Moreover, there are few data on the flight capacity of male S. noctilio. We found no association between parasitism by D. siricidicola and whether or not S. noctilio initiated flight on the flight mill. Male wasps that were parasitized by nematodes were heavier than non-parasitized males, but there was no significant difference in mass between parasitized and non-parasitized females. We also examined the flight capacity of male and female S. noctilio in relation to nematode parasitism, body mass, temperature (for only males), and diel period. Body mass, temperature, and diel period affected flight in S. noctilio such that wasps were generally observed to fly faster, farther, and more frequently if they were heavier, flying at warmer temperatures, and flying during the photoperiod. The fact that nematode-parasitized male wasps were found to fly farther than the non-parasitized males is consistent with the hypothesis that nematode parasitism does not negatively affect the flight capacity of S. noctilio.     

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.     

Multiple introductions of <Emphasis Type="Italic">Sirex noctilio</Emphasis> (Hymenoptera: Siricidae) in northeastern North America based on microsatellite genotypes,and implications for biological control

The invasive woodwasp Sirex noctilio (Hymenoptera: Siricidae) has been moved from Eurasia into regions in the Southern Hemisphere, where extensive tree mortality has occurred in pines (Pinus spp.) introduced for forestry. More recently this woodwasp was found in northeastern North America, where pines are native, and it is a species of concern due to the economic importance of pines. Understanding the genetic diversity of North American S. noctilio points to new areas of inquiry, particularly regarding the ability of parasitic nematodes to sterilize woodwasps, which could provide control methods in the US and/or Canada. We investigated the genetic diversity of 924 S. noctilio from nine populations from New York and Pennsylvania (US), Ontario (CA), and Queensland (AU) using nine microsatellite loci. To avoid inflating the number of populations estimated by Bayesian inference, we measured the full-sibling relationships of woodwasps within 13 trees and removed all but one member of each full-sib family from the genetic analysis, resulting in a final sample size of 741 S. noctilio. Within a tree, on average 39% of woodwasps did not have a full sibling, and there were 5.6 families with at least two full-sibling members per tree. The mean family size across trees was 1.9 when single offspring (i.e., no full siblings) were included. Given the short time span since invasion, variation within North American S. noctilio is likely due to differences among founding genotypes. Genetic analyses support the hypothesis that at least two separate introductions occurred. Within North America, genetic distance measures were greatest between a site in southwestern Ontario and all other sites, suggesting that this population could represent a separate introduction event. Two methods of Bayesian clustering also support this idea; they detected 4 or 5 distinct genetic clusters with little admixture between the southwestern Ontario site and other North American populations. The wasps from Australia, where biological control with nematodes has been successful, showed low genetic diversity and clustered with the southwestern Ontario population in one out of two Bayesian analyses. Within the Ontario subset of samples, high woodwasp activity level (i.e., attack and mortality of trees) was associated with one genetic cluster more strongly than another. Population variation should be taken into account in studies of S. noctilio spread and management within North America.     

Trapping for Sirex Woodwasp in Brazilian Pine Plantations: Lure,Trap Type and Height of Deployment

The Sirex woodwasp, Sirex noctilio (Hymenoptera: Siricidae) is considered a secondary pest of pine in its native range but has caused considerable economic losses in pine plantation forests in the southern hemisphere. In Brazil, trap trees are the primary tool used for early detection purposes but these are costly, labor-intensive to install and require stressing trees by herbicide application. Flight intercept traps baited with synthetic blends of host volatiles are an attractive alternative but have performed poorly in some settings. This study was carried out to look for alternatives to trap trees for use in Brazilian pine plantations for early detection of S. noctilio. Four field experiments were conducted in two consecutive flight seasons (2015–16 and 2016–17), in planted loblolly pine (Pinus taeda) stands, to compare captures among flight intercept traps baited with different lures, deployed at different heights and among different intercept trap designs. Two experiments compared different host volatile lures and a significant treatment effect was observed in one. No effect of trap design or height was observed.     

Maternal inheritance of chloroplast DNA in <Emphasis Type="Italic">Pinus mugo</Emphasis> Turra: a case study of <Emphasis Type="Italic">Pinus mugo</Emphasis> × <Emphasis Type="Italic">Pinus sylvestris</Emphasis> crossing

The opposite modes of chloroplast DNA (cpDNA) inheritance were found to operate in the reciprocal crossings of Scots pine (Pinus sylvestris L.) and mountain dwarf pine (Pinus mugo Turra). The crossings were found to be partially compatible. In P. sylvestris × P. mugo crossing, the paternal transmission of cpDNA to the offspring takes place corroborating the generally acknowledged concept of the paternal cpDNA inheritance in gymnosperms. On the contrary, in P. mugo × P. sylvestris crossing the seed progeny exhibited P. mugo haplotype of the mother tree deviating conspicuously from the above concept. In the open pollination offspring of the putatively hybrid individuals of the Scots and mountain dwarf pines, a biparental inheritance of cpDNA was revealed in mother tree with P. mugo haplotype indicating a loosened control of the maternal inheritance of cpDNA in the putative hybrids. Implications and impacts of this finding for further studies are discussed.     

Mycorrhizal synthesis between <Emphasis Type="Italic">Lactarius deliciosus</Emphasis> and <Emphasis Type="Italic">Arbutus unedo</Emphasis> L.

Arbutoid mycorrhizae were synthesized in vitro between Arbutus unedo L. and two isolates of Lactarius deliciosus. The fungal isolates were obtained from sporocarps collected under Pinus sylvestris and in a mixed forest stand of Quercus suber and Pinus pinea. Synthesis tubes filled with a mixture of sterilized peat, vermiculite, and perlite imbibed with nutrient solution were used. Two inoculation methods using solid and liquid media were tested. Shoots from an adult selected clone of A. unedo were used after in vitro rooting by auxin dipping. After 3 months of shoots transfer to the substrate, the root systems were examined for arbutoid mycorrhizae formation and later on ex vitro conditions, 9 months after acclimatization. The inoculum treatment with liquid medium improved the mycorrhizal development for both isolates, in vitro. Sterilized substrate for plant acclimatization increased the mycorrhizal development. The arbutoid mycorrhizae were observed in vitro as well as 9 months after acclimatization. Standard arbutoid mycorrhiza features were observed: pale yellow mantle, typical cruciform appearance, Hartig net (HN), and intracellular hyphal complexes, both confined to the epidermis. L. deliciosus mycorrhizae synthetized in vitro persisted 9 months after plant acclimatization. Morphological observations were confirmed by molecular techniques.     

<Emphasis Type="Italic">Scolytus multistriatus</Emphasis> associated with Dutch elm disease on the island of Gotland: phenology and communities of vectored fungi

Scolytus multistriatus Marsham, the smaller European elm bark beetle, is a vector for Dutch elm disease (DED) that in the year 2005 invaded the island of Gotland (Sweden). The island possesses the largest population of elm (mainly Ulmus minor Mill.) in northern Europe. The aim of this study was to monitor flying periods of S. multistriatus during three consecutive years and by using high-throughput sequencing to assess communities of vectored fungi. Sampling of the beetles was carried out at two different sites in Gotland in 2012, 2013, and 2014. In total, 50 pheromone traps were placed at each site and checked weekly during June-August each year. From all sites and years, 177 beetles were trapped. Among these, 6.2 % were trapped in June, 76.8 % in July, and 16.9 % in August (difference significant at p<0.007). Sequencing of ITS rDNA from the beetles revealed the presence of 1589 fungal taxa, among which virulent DED pathogen Ophiostoma novo-ulmi Brasier was the second most common species (9.0 % of all fungal sequences). O. ulmi Buisman, the less virulent DED pathogen, was also detected but only in a single beetle, which was sampled in 2012 (0.04 % of sequences). There were 13.0 % of the beetles infested with O. novo-ulmi in 2012, 4.0 % in 2013, and 27.7 % in 2014. O. novo-ulmi comprised 0.8 % of fungal sequences in 2012, 0.002 % in 2013, and 8.2 % in 2014. The study showed that the proportion of S. multistriatus vectoring O. novo-ulmi has increased in recent years.     

Field-based artificial crossings indicate partial compatibility of reciprocal crosses between <Emphasis Type="Italic">Pinus sylvestris</Emphasis> and <Emphasis Type="Italic">Pinus mugo</Emphasis> and unexpected chloroplast DNA inheritance

Crossability relationships between Scots pine (Pinus sylvestris L.) and mountain dwarf pine (Pinus mugo Turra) was studied, using artificial pollination approach. Partial compatibility of the reciprocal crossings of these species was proved experimentally, validating the idea of a spontaneous formation of their hybrid swarms under natural conditions. The hybrids were validated using organellar DNA markers and nuclear DNA microsatellites. Based on the percentage of filled seeds, the interspecific crossings were less efficient than the intraspecific cross-pollinations of P. sylvestris and P. mugo individuals. Both species were found to intercross readily with individuals of their putative hybrid swarm, P. mugo exhibiting a higher hybridological affinity towards putatively hybrid individuals than P. sylvestris. Validation of the hybrids confirmed the paternal inheritance of chloroplast DNA (cpDNA) in the combination P. sylvestris × P. mugo only. Surprisingly, in the reciprocal crossing P. mugo × P. sylvestris, maternal inheritance of cpDNA was revealed. Obtained results offer a new insight into the direction and intensity of gene flow within the hybrid swarms of Scots pine and mountain dwarf pine.     

Characterization of a <Emphasis Type="Italic">Pinus sylvestris</Emphasis> thaumatin-like protein gene and determination of antimicrobial activity of the in vitro expressed protein

Thaumatin-like proteins (TLPs) are pathogenesis-related proteins, which are involved in plant defense responses to pathogen infection. Expression of the Pinus sylvestris L. TLP gene is up-regulated by methyl jasmonate treatment and inoculation with Heterobasidion annosum. A full-length Pinus taeda TLP gene sequence was used to design PCR primers for amplification of the full-length TLP gene from P. sylvestris. A putative 705-bp open reading frame of TLP gene was cloned into Escherichia coli cells, and then subcloned into the overexpression vector pET100 using BL21 Star expression bacteria. Optimization of the expression of recombinant TLP was achieved by decreasing both expression temperature and IPTG concentration. The purified 24.6-kDa TLP shows antimicrobial activity against 12 fungal species.     

The composition of fatty acids in the endosperm and embryo lipids of <Emphasis Type="Italic">Pinus sibirica</Emphasis> and <Emphasis Type="Italic">P. sylvestris</Emphasis> seeds

The fatty acid (FA) composition of storage lipids in the seed endosperms and embryos of two pine species, Pinus sibirica and P. sylvestris, and possible biosynthetic pathways of these acids were studied by the GLC method. Linoleic acid predominated in the embryo and endosperm lipids of both P. sibirica (43.5 and 42.6%) and P. sylvestris (44.8 and 46.8%); this was evidently determined by a high expression of the gene encoding stearoyl-Δ9 acyl-lipid desaturase and the fad2 gene encoding microsomal ω6 acyl-lipid desaturase. P. sibirica lipids of the embryo and endosperm contained more oleic acid (22.0 and 24.0%, respectively) than corresponding P. sylvestris lipids (18.7 and 14%). Storage lipids of conifer seeds contain Δ5-unsaturated FAs: taxoleic (18:2Δ5,9), ephedrenic (18:2Δ5,11), pinoleenic (18:3Δ5,9,12), skiadonic (18:3Δ5,11, 14), and coniferonic (18:4Δ5,9,12,15). In the endosperm and embryos of P. sylvestris, the content of pinolenic acid was higher (22.1 and 19.6%) than in P. sibirica seeds (19.1 and 18.6%).     

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.     

Adaptive Responses of Morphological Forms of the Pine (<Emphasis Type="Italic">Pinus sylvestris</Emphasis> L.) under Stressful Conditions of the Northern Taiga (in the Northern Dvina Basin)

The variability of physiological and biochemical indicators and radial growth of different forms of Pinus sylvestris L. f. (var.) sulfuranthera Kozubow and f. (var.) erythranthera Sanio under flooding conditions has been studied. It is shown that the dynamics of photosynthetic pigments (chlorophylls and carotenoids), proline, proteins, ascorbic acid, peroxidase activity, and the light-harvesting complex in the pine needles depend on meteorologic factors and the phenophase. Forms with different colors of anthers differ in seasonal dynamics of the content of stressful metabolites and age variability of the radial growth of wood. Our results indicate that different forms of Pinus sylvestris L. have nuances in adaptation to stress conditions.     

<Emphasis Type="Italic">Streptomyces sanglieri</Emphasis> which colonised and enhanced the growth of <Emphasis Type="Italic">Elaeis guineensis</Emphasis> Jacq. seedlings was antagonistic to <Emphasis Type="Italic">Ganoderma boninense</Emphasis> in in vitro studies

Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784^T and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 10⁹ cfu/ml showed significant (P < 0.05) increase in oil palm seedlings growth when compared to the control. Streptomyces sanglieri strain AUM 00500 successfully colonised the epidermal surface of the roots of treated oil palm seedlings and it was recovered from root fragments plated on starch casein agar.     

Cytotoxic effect of <Emphasis Type="Italic">Semialarium mexicanum</Emphasis> (Miers) Mennega root bark extracts and fractions against breast cancer cells

The root bark of Semialarium mexicanum (Miers) Mennega (cancerina) is traditionally used in Mexico to treat cancer. However, there are no studies supporting its use. We evaluated whether S. mexicanum root bark induces cytotoxicity in breast cancer cells to determine if it has potential applications in the treatment of this disease. Extracts of S. mexicanum root bark in petroleum ether, ethanol, and water were obtained by ultrasound-assisted extraction. MTT and WST-1 assays were used to evaluate the cytotoxicity of the extracts toward breast cancer cells (MDA-MB-231 and MCF7), non-tumorigenic breast-derived cells (MCF 10A), and peripheral blood mononuclear cells (PBMCs). For the extract with greatest cytotoxicity, induction of apoptosis and oxidative stress were determined using flow cytometry. The extract was fractionated, and the cytotoxicity of its fractions was evaluated with the four cell types. The fractions were also analyzed by HPLC. Only the petroleum ether extract was cytotoxic for all cell types (MDA-MB-231?>?MCF 10A/MCF7?>?PBMCs). Cell death occurred by apoptosis, which could be associated with the induction of oxidative stress. Two fractions that were highly cytotoxic for breast cancer cells were obtained from this extract (IC₅₀?≤?4.15 µg/mL for the most active fraction at 72 h). The MCF 10A cells were less affected, while PBMCs were not affected after 72 h of treatment. Pristimerin was identified in both fractions and may be partially responsible for the cytotoxic effect. These results suggest that S. mexicanum root bark has a potential application in breast cancer treatment.     

Persistence of ecto- and ectendomycorrhizal fungi associated with <Emphasis Type="Italic">Pinus montezumae</Emphasis> in experimental microcosms

Ectomycorrhizal (ECM) and ectendomycorrhizal fungal species associated with Pinus montezumae were recorded in 8 year-old trees established in microcosms and compared with those associated with 2 year-old trees, in order to determine their persistence over the long-term. Mycorrhizal root tips were morphologically and anatomically characterized and sequenced. The extension of extramatrical mycelium of ECM fungi with long exploration strategies was evaluated. In total, 11 mycorrhizal species were registered. Seven mycorrhizal species were detected on both 2 and 8 year-old pines: Atheliaceae sp., Rhizopogon aff. fallax, R. aff. occidentalis, Suillus pseudobrevipes, Tuber separans, Wilcoxina mikolae and Wilcoxina rehmii. One species, Thelephora terrestris, was exclusively associated with two year–old seedlings, while Cenococcum geophilum, Pezizaceae sp. and Pyrenomataceae sp. were exclusively found on 8 year-old trees. Atheliaceae sp. was the ECM fungal species that presented the most abundant mycelium. Finally, we report one new fungal species of Pezizaceae occurring as a symbiont of P. montezumae.     

Control of postharvest soft rot caused by <Emphasis Type="Italic">Erwinia carotovora</Emphasis> of vegetables by a strain of <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis> and its potential modes of action

Erwinia carotovora subsp. carotovora (Ecc), the causal agent of bacterial soft rot, is one of the destructive pathogens of postharvest vegetables. In this study, a bacterial isolate (BGP20) from the vegetable farm soil showed strong antagonistic activity against Ecc in vitro, and its twofold cell-free culture filtrate showed excellent biocontrol effect in controlling the postharvest bacterial soft rot of potatoes at 25 °C. The anti-Ecc metabolites produced by the isolate BGP20 had a high resistance to high temperature, UV-light and protease K. Based on the colonial morphology, cellular morphology, sporulation, and partial nucleotide sequences of 16S rRNA and gyrB gene, the isolate BGP20 was identified as Bacillus amyloliquefaciens subsp. plantarum. Further in vivo assays showed that the BGP20 cell culture was more effective in controlling the postharvest bacterial soft rot of green peppers and Chinese cabbages than its twofold cell-free culture filtrate. In contrast, the biocontrol effect and safety of the BGP20 cell culture were very poor on potatoes. In the wounds of potatoes treated with both the antagonist BGP20 and the pathogen Ecc, the viable count of Ecc was 31,746 times that of BGP20 at 48 h of incubation at 25 °C. But in the wounds of green peppers, the viable count of BGP20 increased 182.3 times within 48 h, and that of Ecc increased only 51.3 %. In addition, the treatment with both BGP20 and Ecc induced higher activity of phenylalanine ammonia-lyase (PAL) than others in potatoes. But the same treatment did not induce an increase of PAL activity in green peppers. In conclusion, the present study demonstrated that the isolate BGP20 is a promising candidate in biological control of postharvest bacterial soft rot of vegetables, but its main mode of action is different among various vegetables.     

Two new complete mitochondrial genomes of <Emphasis Type="Italic">Dorcus</Emphasis> stag beetles (Coleoptera,Lucanidae)

The systematics of Dorcus MacLeay has been a long-standing debate. Mitochondrial genomes were widely used to deeply understand the phylogeny of problematic taxa in virtue of their genetic importance and comprehensiveness. To provide more useful genetic data for resolving the systematic disputation of Dorcus stag beetles. The complete mitochondrial genomes of Dorcus hopei and Dorcus seguyi were obtained using the next generation sequencing. Characteristics of the two genomes are explicated through comparing their genome organization and base composition, protein-coding genes and codon usage, intergenic spacers and non-coding region, transfer and ribosomal RNA genes and control region. Phylogenetic relationships were reconstructed using Maximum likelihood and Bayesian inference analyses based on the concatenated nucleotide sequences of 13 PCGs from 9 stag beetles and 3 scarab beetles. The complete mitogenomes of D. hopei and D. seguyi was 16,026 bp/17,955 bp long, respectively. A tandem repeat with the length of 940 bp was presented in the A+T-rich region in D. hopei. An unexpected non-coding region of 332 bp was located between nad2 and trnW in D. seguyi. The phylogenetic analyses robustly supported that D. hopei formed a branch with the generic type of D. parallelipipedus. Whereas D. seguyi was not covered in the branch of (D. hopei?+?D. parallelipipedus), but was sister to them. The results indicated that D. hopei should be a good member of Dorcus MacLeay. The taxonomic status of D. seguyi remained to be studied furtherly.     

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.