Brief Review of the Associations of Xylobiont Nematodes with Bark Beetles (Coleoptera,Curculionidae: Scolytinae)

Nematode pathogens cause wilt diseases in conifers and deciduous trees. The longhorn beetles (Coleoptera: Cerambycidae) and bark beetles (Coleoptera: Curculionidae: Scolytinae) act as nematode vectors spreading the invasive juvenile stages during their maturation feeding or during oviposition on the plant hosts. There are numerous reviews of nematodes associated with bark beetles on conifers, while little attention has been paid to the nematodes of deciduous trees. The development of Dutch elm disease and ash dieback is mainly caused by fungal pathogens transmitted by bark beetles; the latter act as vectors of not only fungi but also nematodes enclosed in nematangia under their elytra, and also in the tracheae and Malpighian canals. Apart from phytopathogenic nematodes, bark beetles transmit mycophagous and bacterivorous nematodes and own parasites of bark beetles. The ecological groups of nematodes associated with Scolytinae are reviewed; the known records of associations of nematodes with bark beetles are listed for coniferous host plants of Russia and neighboring countries; the world-wide list of these associations for deciduous plant hosts is given.

     

The Polyphagous Bark Beetle Hypothenemus eruditus (Westwood, 1836) (Coleoptera,Curculionidae, Scolytinae): the First Record on Buxus Trees in Russia

Entomological Review - The formation of Hypothenemus eruditus foci is described on a tree of Buxus sempervirens ssp. colchica which died as the result of damage caused by larvae of Neoglyphodes...     

First Record of the Four-Eyed Fir Bark Beetle Polygraphus proximus Blandford, 1894 (Coleoptera,Curculionidae: Scolytinae) from Irkutsk Province,Russia

Entomological Review - Polygraphus proximus Blandford, 1894 is recorded for the first time for Irkutsk Province of Russia. The species was collected in the vicinity of Utulik Village in Slyudyansky...     

Distribution and Trophic Associations of Herbivorous Bark Beetles of the Genus Thamnurgus Eichhoff (Coleoptera,Curculionidae: Scolytinae) in the Volga Region and in the Urals

Entomological Review - Based on the author’s and literature data, three species of the scolytid genus Thamnurgus Eichhoff, 1864 associated with herbaceous plants are reported from the Volga...     

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.     

Taxonomic changes in palaeotropical Xyleborini (Coleoptera, Curculionidae, Scolytinae)

Following the recent reclassification of the Palaeotropic xyleborine genera (Hulcr and Cognato in press), additional species are transferred to correct genera or synonymized based on analysis of their morphological characters. The following species are given new combinations: Debus amphicranoides (Hagedorn), comb. n., Debus birmanus (Eggers, 1930), comb. n., Debus dolosus (Blandford, 1896), comb. n., Debus eximius (Schedl, 1970), comb. n., Debus interponens (Schedl, 1954), comb. n., Debus robustipennis (Schedl, 1954), comb. n., Debus spinatus (Eggers, 1923), comb. n., Microperus alpha (Beeson, 1929), comb. n., Microperus corporaali (Eggers), comb. n., Microperus eucalyptica (Schedl, 1938), comb. n., Microperus nugax (Schedl, 1939), comb. n., Pseudowebbia percorthylus (Schedl, 1935), comb. n., Truncaudum circumcinctus (Schedl, 1941), comb. n.THE FOLLOWING SPECIES ARE SYNONYMIZED: Arixyleborus hirtipennis (Eggers), syn. n., with Arixyleborus puberulus (Blandford); Coptoborus palmeri (Hopkins), syn. n., with Debus emarginatus (Eichhoff); Coptoborus terminaliae (Hopkins), syn. n., with Debus emarginatus (Eichhoff); Cyclorhipidion polyodon (Eggers), syn. n., with Truncaudum agnatum (Eggers); Euwallacea artelaevis (Schedl), syn. n., with Planiculus bicolor (Blandford); Xyleborinus perminutissimus (Schedl), syn. n., with Xyleborinus perpusillus (Eggers); Xyleborus exesus Blandford, syn. n., with Debus emarginatus (Eichhoff); Xyleborus fulvulus (Schedl), syn. n., with Microperus corporaali (Eggers); Xyleborus marginicollis (Schedl), syn. n., with Diuncus justus (Schedl); Xyleborus shoreae Stebbing, syn. n., with Debus fallax (Eichhoff).THE FOLLOWING SPECIES ARE GIVEN NEW STATUS: Streptocranus superbus (Schedl, 1951), restored name; Webbia divisus Browne, 1972, restored name; Webbia penicillatus (Hagedorn, 1910), restored name. Genus Taphrodasus Wood (1980) is declared not valid.     

Evaluating the Efficacy of Entomopathogenic Fungi against the Bark Beetle,Ips stebbingi Strohmeyer (Coleoptera,Curculionidae: Scolytinae) in India

The bark beetle, Ips stebbingi Strohmeyer (Coleoptera: Curculionidae: Scolytinae) is one of the most serious pests of Pinus wallichiana A. B. Jacks (Pinaceae) in Kashmir Himalaya. In order to find an effective biocontrol agent against this pest, we determined the effectiveness of entomopathogenic fungi, viz. Beauveria bassiana (Balsamo) Vuillemin, Metarhizium anisopliae sensu lato (Metchnikoff) Sorokin, and Lecanicillium lecanii (Zimmerman) Zare et Gams against I. stebbingi in the laboratory conditions. Each fungal suspension contained 1.0 × 10⁹ spores of fungi in 1 ml. The insecticide (cyclone 505 EC) was also used as positive control in the experiment. The mortality caused with these fungi was recorded in treated branches and Petri dish assay. In treated branches, B. bassiana and M. anisopliae caused higher mortality, i.e., 68% and 71.25%, respectively, 10 days after treatment, and 93.10% and 88%, respectively, 20 days after treatment. The results of Petri dish assay revealed that I. stebbingi adults were highly susceptible to both treated fungal species and insecticide. However, B. bassiana and M. anisopliae caused higher percentage mortality six days after treatment, i.e., 94.16% and 100% respectively. The percentage of mortality caused by treating with insecticide was 60%. Lecanicillium lecanii was found significantly less virulent (mortality 18.33%) in all fungal treatments. Results obtained in the present study are promising and may be used as alternative means of chemical control for management of this beetle pest; however, no recommendations concerning the potential use of these fungal pathogens for forest protection can be given, and further studies are needed in this respect, especially under field conditions.

     

North American Lauraceae: Terpenoid Emissions,Relative Attraction and Boring Preferences of Redbay Ambrosia Beetle,Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.     

Bark beetles and pinhole borers (Curculionidae, Scolytinae, Platypodinae) alien to Europe

Invasive bark beetles are posing a major threat to forest resources around the world. DAISIE's web-based and printed databases of invasive species in Europe provide an incomplete and misleading picture of the alien scolytines and platypodines. We present a review of the alien bark beetle fauna of Europe based on primary literature through 2009. We find that there are 18 Scolytinae and one Platypodinae species apparently established in Europe, from 14 different genera. Seventeen species are naturalized. We argue that Trypodendron laeve, commonly considered alien in Europe, is a native species; conversely, we hypothesize that Xyleborus pfeilii, which has always been treated as indigenous, is an alien species from Asia. We also point out the possibility that the Asian larch bark beetle Ips subelongatus is established in European Russia. We show that there has been a marked acceleration in the rate of new introductions to Europe, as is also happening in North America: seven alien species were first recorded in the last decade.We present information on the biology, origins, and distributions of the alien species. All but four are polyphagous, and 11 are inbreeders: two traits which increase invasiveness. Eleven species are native to Asia, six to the Americas, and one is from the Canary Islands. The Mediterranean is especially favorable for invasives, hosting a large proportion of the aliens (9/19). Italy, France and Spain have the largest numbers of alien species (14, 10 and 7, respectively). We point out that the low numbers for at least some countries is likely due to under-reporting.Finally, we discuss the difficulties associated with identifying newly invasive species. Lack of good illustrations and keys hinder identification, particularly for species coming from Asia and Oceania.     

Areography of the genus Dendroctonus (Coleoptera: Curculionidae: Scolytinae) in Mexico

Objective To analyse whether the geographical ranges of Dendroctonus species are (1) associated with factors such as host species or elevation, and (2) in agreement with Halffter's Nearctic distribution pattern. (3) To identify and discuss the factors that are likely to act as barriers to the genus’ geographical distribution. (4) To explore whether there is an association between the size of the geographical ranges of Dendroctonus species and the number of Pinus host species used by each of them, and (5) to assess if these host species are most common at the elevations preferred by the individual Dendroctonus species. Site Mexico. Methods Records of 12 species of Dendroctonus were gathered from entomological collections in Mexico. Distribution ranges were defined by using the propinquity method ( Rapoport, 1975a ). Analysed parameters were: (1) geographical distribution of single species, (2) overlapping of species ranges, (3) disjunction patterns and barriers by means of isoprobabilistic lines, based on the morphotectonic subdivision of Mexico ( Ferrusquía‐Villafranca, 1998 ), (4) spatial variation in species richness with respect to latitude and altitude, (5) size of geographical ranges, and (6) host species for each Dendroctonus species. A correlation was determined between area size and number of pine host species. Results The species ranges varied in shape and size. Geographical ranges tend to be discontinuous in shape. Composite patterns showed that disjunctions among ranges do not closely follow Mexico's morphotectonic subdivision. There are repeated discontinuities among individual distributions, which define five areas: (1) Baja California Peninsula, (2) Sierra Madre Occidental (SMOC), (3) northern Sierra Madre Oriental (SMOR), (4) Sierra Madre de Chiapas, and (5) SMOR + Faja Volcanica Transmexicana (FVT) + Sierra Madre del Sur. The isoprobabilistic lines confirm that the inner part of SMOC provides an optimal environment for the genus, and the FVT province constitutes the broader corridor for it in the country. Richness does not directly decrease or increase with latitude. Richness behaviour of the insect is not associated with that of its host. Elevation distributions showed that most Dendroctonus species move within broad margins of tolerance and species richness is concentrated in the montane interval. Dendroctonus attack 24 of the 47 Pinus species distributed in Mexico. Preferred pine species belong predominantly to Leiophyllae, Ponderosae and Oocarpae subsections. The Spearman rank correlation between area size and number of pine host species was not significant. Dendroctonus clearly belongs to a Nearctic distribution pattern (sensu Halffter, 1987 ). Main conclusions Dendroctonus is present in all montane systems of Mexico and its species coexist within a high geographical sympatry. Overlapping of species distribution appears to be the result of two elements – generalized polyphagy inside Pinus and a wide elevation tolerance within mountainous environments. This behaviour, linked to a high vagility, has allowed the genus Dendroctonus to expand its distribution across Mexico and to employ mountainous systems as corridors separated by barriers that exert a low selective filter effect.     

Small Spruce Bark Beetle Ips amitinus (Eichhoff, 1872) (Coleoptera,Curculionidae: Scolytinae): a New Alien Species in West Siberia

The small spruce bark beetle Ips amitinus is a widespread species in many European countries that has been actively spreading into Northern Europe in the recent decades. In Russia, I. amitinus is present in the western, northwestern, and northern regions of the European part, with a tendency for range expansion. The species was first recognized in West Siberia in 2019 by characteristic morphological features and molecular genetic analysis. This bark beetle is abundant on Pinus sibirica in Siberian pine forests located near settlements within Tomsk and Kemerovo provinces, and is also sporadically found on the Siberian spruce Picea obovata. It colonizes the upper trunk and branches of standing and windfall trees. In the outbreak foci this bark beetle causes catastrophic drying of Siberian pines, starting from the crown top. This pattern of tree drying was noted for the first time near settlements in Yashkinsky District of Kemerovo Province in 2014, and now outbreak foci of I. amitinus exist in all the Siberian pine forests in this district. The population growth of I. amitinus was probably facilitated by dry and hot summer weather in the southeast of West Siberia during the last decade, in 2011 and 2012, and also by heavy winter snowfalls leaving numerous snapped tree branches which are easily colonized by the pest. In Tomsk Province, the most active outbreak focus of I. amitinus appeared in 2018 in the Siberian pine forest near Luchanovo and Ipatovo, following an outbreak of the Siberian moth Dendrolimus sibiricus. The invasion of I. amitinus in Siberia may increase the degradation rates not only of the gene-reserve Siberian pine forests but also of other dark coniferous stands.

     

中国寄生于木蠹象和小蠹虫的三盾茧蜂一新种(膜翅目:茧蜂科)

记述采自黑龙江小兴安岭寄生于木蠹象和小蠹虫的茧蜂科1新种——木蠹三盾茧蜂Triaspisnanchaensissp.nov.,模式标本的正模保存于中国林业科学研究院昆虫标本馆,副模保存于东北林业大学昆虫标本室。     

Alimentary canal and reproductive tract of Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae, Scolytinae)

The alimentary canal and the reproductive tract of males and females of Hypothenemus hampei Ferrari are described. The alimentary canal of H. hampei showed the crop with several spine-like structures and the midgut with few gastric caeca. We evidenced for the first time that adult females need to feed on coffee in order to produce viable eggs before and during oviposition period. The presence of air bubbles inside the anterior midgut may be due to starvation rather than the response of the environment during flying as previously reported. Two ovaries and the same structures and arrangements common to individuals of the Curculionidae beetles composed the female reproductive system. The male reproductive tract showed a significant difference with respect to other Curculionidae and even other Scolytinae species as it showed a sclerotized aedeagus with several pore-like structures in the terminal portion where sperm is released during mating.     

Phylogeography of the bark beetle Dendroctonus mexicanus Hopkins (Coleoptera: Curculionidae: Scolytinae)

Dendroctonus mexicanus is polyphagous within the Pinus genus and has a wide geographical distribution in Mexico and Guatemala. We examined the pattern of genetic variation across the range of this species to explore its demographic history and its phylogeographic pattern. Analysis of the mtDNA sequences of 173 individuals from 25 Mexican populations allowed to us identify 53 geographically structured haplotypes. High haplotype and low nucleotide diversities and Tajima’s D indicate that D. mexicanus experienced rapid population expansion during its dispersal across mountain systems within its current range. The nested clade phylogeographic analysis indicates that the phylogeographic pattern of D. mexicanus is explained by continuous dispersion among lineages from the Sierra Madre Occidental, the Sierra Madre Oriental and the Trans-Mexican Volcanic Belt. However, we also observed isolation events among haplotypes from the Cofre de Perote/Trans-Mexican Volcanic Belt/Sierra Madre Oriental and the Trans-Mexican Volcanic Belt/Sierra Madre del Sur, which is consistent with the present conformation of mountain systems in Mexico and the emergence of geographical barriers during the Pleistocene.     

Mating Behavior of the Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae)

The mating behavior of the coffee berry borer, Hypothenemus hampei (Ferrari), was observed under laboratory conditions. Pairs of adult virgin male and female beetles were placed in the wells of a polystyrene microtiter plate, one pair per well. The mating activity of each pair was recorded for 24?h. The mating behavior of the coffee berry borer was similar to that of other Scolytinae and was clearly divided into precopulatory, copulatory and postcopulatory phases. The beetles started to mate within a few hours of emergence. Repeated mating occurred during the 24-hour period and increased in frequency with age. However, we cannot address multiple matings in H. hampei, since we did not simulate the female-biased sex ratio of this species and the experimental design did not allow females to avoid additional mating attempts by males. In addition, further studies are necessary that focus on the effectiveness of sperm transmission and direct and indirect effects of multiple matings on the H. hampei females and their offspring.     

Lamellicorn Beetles (Coleoptera,Scarabaeoidea) of Manchuria (China): Fauna,Ecology, and Zoogeography

The species composition and taxonomic structure of lamellicorn beetles of Northeast China are considered. A total of 317 species from 86 genera, 42 tribes, 18 subfamilies, and 6 families are known to occur in the fauna of Manchuria. Seven species are recorded from China for the first time: Trox scaber (Linnaeus, 1767), Glyptotrox ineptus (Balthasar, 1931), Aegialia (Psammoporus) kamtschatica Motschulsky, 1860, Aphodius (Acrossus) superatratus Nomura et Nakane, 1951, Aphodius (Chilothorax) grafi Reitter, 1901, Maladera spissigrada (Brenske, 1897), and Valgus hemipterus hemipterus (Linnaeus, 1758); in addition, 18 species are recorded as new to the fauna of Manchuria. Among 177, 219, 208 and 226 species recorded from the Manchurian part of Inner Mongolia, Heilongjiang, Jilin, and Liaoning, 20, 29, 14 and 19 species are new to the region, respectively. The ecological and zoogeographical features of Scarabaeoidea in Manchuria are analyzed. Data on the trophic structure, phenology, and distribution of all the taxa are presented.     

Five new species of Triotemnus (Coleoptera, Curculionidae, Scolytinae) from Morocco and Yemen

Fivenew species of the genus Triotemnus from Morocco and Yemen are described. Triotemnus is a new genus of Scolytinae for the Yemen region. External morphology of the new species and all morphologically related species of the genus were studied. While the new species from Morocco are morphologically similar to the known species from the corresponding region, all three newly described species from Yemen, mainly two of them living in Socotra, are morphologically very different from all other known species of the genus. Geographical distribution and the probability of endemicity are discussed.     

A New Genus and Species of Scolytinae (Coleoptera: Curculionidae) from the Rovno Amber

A new genus, Klesovia gen. nov., with the species K. pubescens sp. nov. (Coleoptera: Curculionidae) are described from the Rovno amber. The new genus is closely related to Xylechinus (tribe Hylurgini) and distinguished by the wide flattened ovoid antennal club with rounded apex and the metepisternum covered with long thin sparse setae; it differs from other genera of Hylurgini in having a five-segmented funicle, four-segmented club, and large distance between the procoxa.     

Click Beetles (Coleoptera,Elateridae) in Agrolandscapes of Northwestern Russia

Entomological Review - A total of 44 species of click beetles (Coleoptera, Elateridae) were recorded in the agricultural landscapes of Northwestern Russia; 23 species were found in various crop...