Bark beetles and pinhole borers recently or newly introduced to France (Coleoptera: Curculionidae, Scolytinae and Platypodinae)

Commodity risk assessment of Corylus avellana plants from the UK

The European Commission requested the EFSA Panel on Plant Health to prepare and deliver risk assessments for commodities listed in Commission Implementing Regulation (EU) 2018/2019 as 'High risk plants, plant products and other objects'. This Scientific Opinion covers plant health risks posed by plants of Corylus avellana imported from the United Kingdom (UK) as: (a) bundles of 1- to 2-year old whips or transplants, (b) bundles of 1- to 2-year old cell grown plants, (c) 1- to 7-year old bare root single plants and (d) up to 15-year old single plants in pots, taking into account the available scientific information, including the technical information provided by the UK. All pests associated with the commodity were evaluated against specific criteria for their relevance for this opinion. Two EU quarantine pests, Phytophthora ramorum (non-EU isolates) and Thaumetopoea processionea fulfilled all relevant criteria and were selected for further evaluation. For the selected pests, the risk mitigation measures implemented in the technical dossier from the UK were evaluated taking into account the possible limiting factors. For these pests an expert judgement is given on the likelihood of pest freedom taking into consideration the risk mitigation measures acting on the pest, including uncertainties associated with the assessment. In the assessment of risk, the age of the plants was considered, reasoning that older trees are more likely to be infested mainly due to longer exposure time and larger size. The degree of pest freedom varies among the pests evaluated, with P. ramorum being the pest most frequently expected on the imported plants. The expert knowledge elicitation indicated with 95% certainty that between 9939 and 10,000 of the single plants in pots up to 15-year old will be free from P. ramorum (non-EU isolates).

Checklist of the subfamily Scolytinae (Coleoptera: Curculionidae) in Tucumn province, Argentina

A checklist of Scolytinae species is presented to contribute to the knowledge of the biodiversity of the subfamily in Tucumn province, Argentina. The inventory was based on collections in the field from 2016 to 2023, and a review of the material deposited in the entomological collections of the Museo de La Plata, the Museo Argentino de Ciencias Naturales Bernardino Rivadavia, and the Fundacin Miguel Lillo. Previous bibliographic records were also included. In total, 54 species belonging to 11 tribes were recorded, of which six were new reports for Argentina and nine for Tucumn province; eight species were introduced. The genus Amasa was also recorded in Argentina for the first time.

Taxonomic reappraisal of the European fauna of the bark beetle genus Cryphalus (Coleoptera, Curculionidae, Scolytinae)

Species in the genus Cryphalus are small and notoriously difficult to identify. Even among the relatively well studied European species, erroneous identifications are evident from literature and in museum collections. These misidentifications relate to the small size and similar appearance of Cryphalus species but they are also a product of insufficient diagnostic characters. This is especially unfortunate since some European species are considered pests. Based on the study of more than 1000 specimens and a thorough literature review, robust morphological and molecular evidence supporting all five hitherto recognised native species of Cryphalus in Europe is provided. A key for the reliable identification of these repetition species including new diagnostic characters recognised for the first time, including those from male genitalia, has been constructed. Each native species is provided with a detailed morphological description and their economic significance, distribution, and ecology discussed. Significant genetic variability is observed between certain clusters that should be further explored in a broader geographic context. Lastly, the need for a taxonomic revision of the genus Cryphalus for the entire Palearctic region due to the presence of many similar looking species which are often confused, thus distorting the knowledge of each species is highlighted.

New species and new records of exotic Scolytinae (Coleoptera, Curculionidae) in Europe

Background

Bark and ambrosia beetles (Coleoptera, Scolytinae) are amongst the most important wood-boring insects introduced to Europe. During field investigations conducted between 2019 and 2021 in different countries and regions of Europe, many exotic species have been recorded providing new and relevant data.

New information

Dryoxylononoharaense (Murayama, 1933) is recorded in Europe for the first time. Xyleborinusattenuatus (Blandford, 1894) is a species new to Italy, while Xylosandrusgermanus (Blandford, 1894), Hypothenemuseruditus (Westwood, 1836) and Amasa sp. near A.truncata are new country records for Portugal. Cnestusmutilatus (Blandford, 1894), Phloeotribusliminaris (Harris, 1852) were collected in Italy and Amasa sp. near A.truncata was collected in France after the first discovery, confirming their establishment and their dispersal into new areas.

First record of Xyleborus bispinatus (Coleoptera: Curculionidae, Scolytinae) and evidence of stable populations in the Iberian Peninsula

We present the first record of the tropical ambrosia beetle Xyleborus bispinatus in the Iberian Peninsula, collected in traps located in Murcia, Alicante and Valencia provinces (Spain). Insects have been captured in baited traps of long-time trapping networks (ESFP, MUFFET, RAT and SAMFIX) installed in Eastern Spain. Several individuals (410) of X. bispinatus have been collected in seven locations, first in 2009 in Murcia Region, and from 2018 to 2021 in Valencia Region. No attacks by X. bispinatus have been detected on plants thus far, and therefore the host plant in Spain remains unknown. Stable X. bispinatus populations have been detected in a wide area of central Valencian province. We may consider this as an alarming scenario that should be kept under surveillance by maintaining the current trapping network and intensifying the search for the host plants.  

Potential European Geographical Distribution of Gnathotrichus materiarius (Fitch, 1858) (Coleoptera: Scolytinae) under Current and Future Climate Conditions

Gnathotrichus materiarius (Fitch, 1858) is an alien ambrosia beetle from North America, that has been spreading across Europe since the 1930s. The species infests coniferous trees, excavating galleries in sapwood. However, to date very few studies have predicted changes in ambrosia beetle habitat suitability under changing climate conditions. To fill that gap in the current knowledge, we used the MaxEnt algorithm to estimate areas potentially suitable for this species in Europe, both under current climate conditions and those forecasted for the years 2050 and 2070. Our analyses showed areas where the species has not been reported, though the climatic conditions are suitable. Models for the forecasted conditions predicted an increase in suitable habitats. Due to the wide range of host trees, the species is likely to spread through the Balkans, the Black Sea and Caucasus region, Baltic countries, the Scandinavian Peninsula, and Ukraine. As a technical pest of coniferous sapwood, it can cause financial losses due to deterioration in quality of timber harvested in such regions. Our results will be helpful for the development of a climate-change-integrated management strategy to mitigate potential adverse effects.

DISTRIBUTION OF THE SMALL SPRUCE BARK BEETLE <i>IPS AMITINUS</i> (EICHHOFF, 1872) IN WESTERN SIBERIA

The data on distribution of small spruce bark beetle Ips amitinus (Eichh.) (Coleoptera: Curculionidae: Scolytinae), a new invasive pest of European origin on the territory of Western Siberia are presented. Alien bark beetle species was recorded in the Siberian pine forests of the Tomsk, Kemerovo and Novosibirsk regions. According to the modern data the total invasion range is more than 30 thousand km² with a tendency to further expansion. The number outbreaks of I. amitinus in Siberian pine forests near settlements, in nature preservations and plantations of Pinus sibirica Du Tour cause significant harm to pine-nut harvesting and selective breeding.

Biological Strategies of Invasive Bark Beetles and Borers Species

Simple Summary

Biological invasions are one of the most critical problems today. Invaders have been damaging tree- and shrub-dominated ecosystems. Among these harmful species, a notable role belongs to bark beetles and borers. Extensive phytosanitary measures are needed to prevent their penetration into new regions. However, the lists of quarantine pests should be reasonably brief for more effective prevention of invasion of potentially harmful insects. Our goal is to reveal the set of biological traits of invasive bark beetles and borers that are currently known. We identified four invasion strategies. Inbred, the first one is characterized by inbreeding, parthenogenesis, polyvoltinism, xylomycetophagy, flightless males, polyphagy, to less extent by association with pathogenic fungi. For the second, polyphagous, typical traits are polyphagy, feeding on wood, high fecundity, distance sex pheromones presence, development for one year or more. The third strategy, intermediate, possesses such features as mono- or olygophagy, feeding on inner-bark, short (one year or less) life cycle. Aggressive, the last one includes monophagous species using aggregation pheromones, associated pathogens, short life cycle, and consuming inner-bark. The main traits contributing to significant damage are high fecundity, polyvoltinism, symbiotic plant pathogens, long-range or aggregation pheromones.

Abstract

The present study attempts to identify the biological characteristics of invasive (high-impact in the secondary area) bark beetles and borers species, contributing to their success in an invaded area. We selected 42 species based on the CABI website data on invasive species and information on the most studied regional faunas. Four groups of species with different invasion strategies were identified based on the cluster and factor analysis. The first one (inbred strategy) is characterized by flightless males, xylomycetophagy, low fecundity (~50 eggs), inbreeding, polyvoltinism, and polyphagy. Species with an aggressive strategy are poly- or monovoltine, feeds on a limited number of hosts, larval feeding on the inner bark, are often associated with phytopathogens, and produce aggregation pheromones. Representatives of the polyphagous strategy have a wide range of hosts, high fecundity (~150 eggs), larval feeding on wood, and their life cycle is at least a year long. For the intermediate strategy, the typical life cycle is from a year or less, medium fecundity, feed on inner bark tissues, mono- or oligophagy. Comparison with low-impact alien species showed that the most significant traits from the viewpoint of the potential danger of native plant species are high fecundity, polyvoltinism, presence of symbiotic plant pathogens, long-range or aggregation pheromones.