19 research outputs found
First record of Beauveria bassiana on Tomicus minor in Sicily
No full textTomicus minor (Hartig) (Coleoptera Curculionidae Scolytinae) was found breeding in Pinus nigra calabrica (for the first time in
this subspecies) in the Etna national park (Sicily) in two sites in 2013 and in another site in 2015. We used morphological features
of the beetle, a molecular marker (barcoding region of the COI gene) and characteristics of the breeding system to verify the species
affiliation. The results of these three traits were in accordance. Moreover, we screened living and dead beetles for pathogens.
Dissecting living beetles did not exhibit any pathogens except unidentified hyphae of entomopathogenic fungi. Beauveria bassiana
was found on dead T. minor collected from galleries. Species affiliation was studied by applying cultural, morphological, and
molecular (ITS marker) methods. This is the first evidence of the fungus on this pest confirmed by molecular tools and the first
record of B. bassiana on T. minor in Sicily. These data contribute to the knowledge of the distribution of this beetle in Italy.
Moreover, the findings of B. bassiana bring more light in the pathogen complex of T. minor and help to understand the biology of
this important forest insect
Shallow Genetic Structure among the European Populations of the Six-Toothed Bark Beetle Ips sexdentatus (Coleoptera, Curculionidae, Scolytinae)
No full textThe six-toothed bark beetle, Ips sexdentatus, is one of the most abundant scolytid species of the central and southern European countries. It mostly feeds on Pinus sp., whereas during population outbreaks it can also attack Picea sp. In spite of its broad distribution, its phylogeography has never been studied before. To do that, we employed an mtDNA marker on 489 individuals that covered most of its native range in Europe. Geographic distribution of the 86 haplotypes showed that at least three glacial refugia have played a significant role in shaping the currently observed pattern of genetic divergence in Europe, without excluding the contribution of minor refugial areas that acted in a similar manner. The revealed shallow structure can be considered an artifact of factors that reduced intraspecific diversity, at the same time favoring gene flow. As such, biological traits of the species itself (flying ability and host preference) and even human-mediated transport of wood seem to be the most prevailing and probable reasons that gave rise to the observed pattern.Austrian Science Fund FWF (project number P26749-B25)
Forest Insects and Pathogens in a Changing Environment: Ecology, Monitoring & Genetics (IUFRO Joint Meeting of WP7.03.05 & 7.03.10)
No full textAfter the successful conclusion of the Joint Meeting of IUFRO’s 7.03.05 & 7.03.10 working parties and given the exciting and novel studies that have been presented in the framework of this meeting, we decided to present some of these studies in the current Special Issue of Forests. To make this issue more appealing and interesting to everyone in the field of Forest Protection, studies that cover a wide range of topics were selected, ranging from ecology and phylogeography to forest management and protection. More importantly, as these studies refer to pests and pathogens from different parts of the world, it is expected that the knowledge gained can be further used in the protection of natural environment worldwide
The occurrence of entomopathogenic fungi in soils from mid-field woodlots and adjacent small-scale arable fields
No full textThe aim of this study was to compare the species composition and the intensity of entomopathogenic fungi occurrence in the soil from mid-field woodlots and adjacent small farmlands. The study material consisted of soil samples taken from a mid-field woodlot and an adjacent small-scale arable field in three different localities in the vicinity of Siedlce. Entomopathogenic fungi were isolated from soil using two methods: the insect bait method and the selective medium. The comparative study showed that the soil from mid-field woodlots was characterized by a richer species composition of entomopathogenic fungi than of adjacent arable fields. A total of six fungal species representing the anamorphs of Hypocreales (Ascomycota) were isolated from the soil collected from mid-field woodlots: B. bassiana, B. brongniartii, M. anisopliae, M. flavoviride, I. farinosa and I. fumosorosea. The presence of only three species was reported in the farmland soil: B. bassiana, M. anisopliae and I. fumosorosea. This fact confirms the important role of semi-natural habitats as a source of biodiversity of entomopathogenic fungi in agricultural landscape. It was found that entomopathogenic fungi together formed more colony-forming units in the soil from arable fields than that of neighbouring mid-field woodlots. B. bassiana was the species of fungus which infected more bait insect larvae and formed significantly more colony-forming units (CFU) in the soil from mid-field woodlots than that of farmland in the localities studied, whereas the trend was the opposite in the case of I. fumosorosea and M. anisopliae. Given the presence of entomopathogenic fungi in the farmland soil in the three test places together, it was found that I. fumosorosea was dominant in the soil from the two arable fields, where this fungus infected more G. mellenella larvae and formed significantly more CFUs than the other species of fungi. M. anisopliae was the second most frequently isolated farmland species
Natural Enemies of Bark Beetles
No full textThe occurrence and action of natural enemies of bark beetles (Coleoptera: Curculionidae, Scolytinae) are reviewed. Bark beetles have a diverse and important community of natural enemies. The community includes predators such as birds, beetles, flies, true bugs, and mites; parasitoids such as wasps and flies; pathogens such as viruses, bacteria, fungi, microsporidia, and protozoa; as well as nematodes. The general ecology of the various taxonomic groups is discussed and some of the species most relevant to biological control are treated in detail. Morphological descriptions and the biology of pathogens, field data on natural enemies’ prevalence and geographical distribution are presented. The role of these antagonistic agents in bark beetle population dynamics and their potential for use as biological control agents are evaluated based on literature, data from experiments, observations in the field, and from controlled laboratory experiments
Morphological and genetic identification of the three pine pests of the genus Tomicus (Coleoptera, Scolytidae) in Europe
No full text1. Morphological characters were elaborated and part of the mitochondrial COI gene was sequenced in order to facilitate the determination of the three European pine bark beetles Tomicus piniperda, T. destruens and T. minor. The sequence information also provided the first information on the phylogenetic and phylogeographical relationships of these species. 2. Three hair rows were found on the antennal club of T. destruens between the second and third suture. Tomicus piniperda had only one row. Three different hair types were detected on the elytra – two hair types were found on T. piniperda, whereas the third hair type was only detected on the elytra of T. destruens. 3. The COI region (445 bp) revealed high sequence divergence among T. destruens, T. piniperda and T. minor. The three species proved to be monophyletic species with 16.98–19.23% sequence divergence. A phylogenetic approach placed T. minor and T. destruens as sister taxa, which contradicts the morphological findings. 4. European populations of T. piniperda shared two haplotypes, indicating a homogenous distribution of the genotypes. In the American populations only one of these European haplotypes was found. The Greek, Italian and Spanish T. destruens populations revealed three population-specific haplotypes, indicating restricted gene flow. 5. Species-specific primers were designed to allow a rapid and definitive determination of the two sibling Tomicus species by PCR
Extended studies on the diversity of arthropod-pathogenic fungi in Austria and Poland
No full textResults of studies on diversity of arthropod-pathogenic fungi in selected habitats in Austria and Poland carried out in the years 2006-2007 and 2009-2010 are discussed. In total 47 species of entomopathogenic fungi were found as pathogens of different arthropods in Austria. Twenty six entomophthoralean species from different insects and one species from mites were identified and 16 of them are recorded as new to Austria. From among 21 species of anamorphic Hypocreales (Ascomycota) affecting arthropods in Austria, 13 species so far have not been known from this country. In total 51 species of fungi affecting different arthropods in Poland were recorded, among them 28 species of Entomophthorales and 23 anamorphic Hypocreales (Ascomycota) were separated. The most frequent species of the entomopathogenic fungi both in agricultural and afforested areas in Austria were the common and usually worldwide distributed cordycipitaceous anamorphs Beauveria bassiana, Isaria fumosorosea and in areas of this study less numerous I. farinosa. The most frequent pathogens occurring in mite communities on plants and in wood infested by insects were Hirsutella species. Several entomophthoralean species developed epizootics that caused high reduction in host populations of different arthropods in both countries. Especially interesting is the first record of mycoses (up to 60% mortality), caused by Zoophthora spp. on Phyllobius beetles in a mixed forest near Białowieża. During our joint research, we found the first time in Poland and Europe, the presence of the fungus Furia cf. shandongensis on earwigs and Hirsutella entomophila on Ips typographus adults in forest habitats. From the feeding sites of the latter bark beetle and other subcortical species in oak bark (mostly Dryocoetes villosus) and D. alni in black alder over a dozen of various Lecanicillium strains - including few of the features not allowing to classify them to any of so far known species – were isolated both from the scolytids and from accompanying them mites, but these materials have now been successively elaborated. From the commonly occurring in these materials acaropathogenic species Hirsutella cf. brownorum, H. minnesotensis, H. nodulosa and H. rostrata, the two latter infected also adult bark beetles, whereas from the larvae and pupae some supposed nematophagous anamorphs were isolated, among them Harposporium janus and Haptocillium sp
Occurrence of Tomicobia seitneri (Hymenoptera: Pteromalidae) and Ropalophorus clavicornis (Hymenoptera: Braconidae) in Ips typographus adults (Coleoptera: Curculionidae: Scolytinae) from Austria, Poland and France
No full text
