Search

Species richness, abundance and biomass of insects have recently undergone marked declines in Europe. We metabarcoded 211 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging had an impact on ca. 3000 species of flying insects in silver fir Pyrenean forests. While forest dieback had no measurable impact on species richness, there were significant changes in community composition that were consistent with those observed during natural forest succession. Importantly, most observed changes were driven by rare species. Variation was explained primarily by canopy openness at the local scale, and the tree-related microhabitat diversity and deadwood amount at landscape scales. The levels of salvage logging in our study did not explain compositional changes. We conclude that forest dieback drives changes in species assemblages that mimic natural forest succession, and markedly increases the risk of catastrophic loss of rare species through homogenization of environmental conditions. Sire et al. examine the effects of climate-induced forest dieback and salvage logging on insect diversity in silver fir Pyrenean forests using metabarcoding. Although no consistent variation in species richness was found, forest dieback cause massive changes in community composition particularly affecting rare species. [ABSTRACT FROM AUTHOR]

The current decline of wild bees puts important ecosystem services such as pollination at risk. Both inventory and monitoring programs are needed to understand the causes of wild bee decline. Effective insect monitoring relies on both mass-trapping methods coupled with rapid and accurate identifications. Identifying wild bees using only morphology can be challenging, in particular, specimens from mass-trapped samples which are often in poor condition. We generated DNA barcodes for 2931 specimens representing 157 species (156 named and one unnamed species) and 28 genera. Automated cluster delineation reveals 172 BINs (Barcodes Index Numbers). A total of 36 species (22.93%) were found in highly urbanized areas. The majority of specimens, representing 96.17% of the species barcoded form reciprocally exclusive groups, allowing their unambiguous identification. This includes several closely related species notoriously difficult to identify. A total of 137 species (87.26%) show a "one-to-one" match between a named species and the BIN assignment. Fourteen species (8.92%) show deep conspecific lineages with no apparent morphological differentiation. Only two species pairs shared the same BIN making their identification with DNA barcodes alone uncertain. Therefore, our DNA barcoding reference library allows reliable identification by non-experts for the vast majority of wild bee species in the Loire Valley. [ABSTRACT FROM AUTHOR]

Understanding the genetic structure of natural enemies is an important step to develop efficient biocontrol programs. The ladybird Iberorhyzobius rondensis Eizaguirre (Coleoptera: Coccinellidae) from the Iberian Peninsula, is a specialized predator and potential biological control of Matsucoccus feytaudi Ducasse (Hemiptera: Matsucoccidae), an invasive alien species in Southeastern France and Italy . M. feytaudi is specialized on Pinus pinaster Aiton. The beetle is also restricted to this habitat. Genetic structure of I. rondensis populations was analysed with the barcode region (COI). It revealed two main refugia areas for the beetle in Iberian Peninsula. Comparative phylogeography of the three trophic levels, plant-herbivore-predator, is discussed. Similar population structure was found for the prey and to some extent for the pine. Indications are given on where to collect the beetles for their use in biocontrol of M. feytaudi, in order to obtain the highest genetic diversity and match with the origin of the invasive prey. [ABSTRACT FROM AUTHOR]