Molecular methods for the detection and identification of parasitoids within larval wheat midges.

Three species of cecidomyiid midges (Diptera: Cecidomyiidae) cause significant yield losses on wheat in Europe: Sitodiplosis mosellana (Géhin), Contarinia tritici (Kirby) and Haplodiplosis marginata (von Roser). Eggs and young larvae may be parasitised by a complex of hymenopteran parasitoids belonging to the Pteromalidae and Platygastridae families which contributes to natural pest control. We have developed molecular tools for detecting and identifying seven parasitoid species previously encountered in Belgium inside individual wheat midge larvae.

Enhancing Buprestidae monitoring in Europe: Trap catches increase with a fluorescent yellow colour but not with the presence of decoys.

This study investigated the efficacy of various traps differing in colour (green or yellow), presence or absence of decoys (dead Agrilus planipennis) or design (commercial MULTz or multifunnel traps, and homemade bottle- or fan-traps) for monitoring European Buprestidae in deciduous forests and pear orchards. Over two years, we collected 2220 samples on a two-week basis from 382 traps across 46 sites in Belgium and France. None of the traps proved effective for monitoring Agrilus sinuatus in infested pear orchards (17 specimens captured in 2021, 0 in 2022).

How reliable is metabarcoding for pollen identification? An evaluation of different taxonomic assignment strategies by cross-validation.

Metabarcoding is a powerful tool, increasingly used in many disciplines of environmental sciences. However, to assign a taxon to a DNA sequence, bioinformaticians need to choose between different strategies or parameter values and these choices sometimes seem rather arbitrary. In this work, we present a case study on ITS2 and databases used to identify pollen collected by bees in Belgium.

Do pheromone traps help to reduce new attacks of at the local scale after a sanitary cut?

The spruce bark beetle, , is causing severe economic losses during epidemic phases triggered by droughts and/or windstorms. Sanitation felling and salvage logging are usually the most recommended strategies to limit the damages. However, any additional control method to limit the economic impact of an outbreak would be welcome.

A detailed workflow to develop QIIME2-formatted reference databases for taxonomic analysis of DNA metabarcoding data.

Background: The DNA metabarcoding approach has become one of the most used techniques to study the taxa composition of various sample types. To deal with the high amount of data generated by the high-throughput sequencing process, a bioinformatics workflow is required and the QIIME2 platform has emerged as one of the most reliable and commonly used. However, only some pre-formatted reference databases dedicated to a few barcode sequences are available to assign taxonomy.

Genetic and environmental factors affecting the expression of α-gliadin canonical epitopes involved in celiac disease in a wide collection of spelt (Triticum aestivum ssp. spelta) cultivars and landraces.

Background: Celiac disease (CD) is an autoimmune disorder affecting genetically predisposed individuals whose dietary gluten proteins trigger an inflammatory reaction in the small intestine. Gluten is found in the seeds of cereals like bread wheat (Triticum aestivum ssp. aestivum) and spelt (Triticum aestivum ssp.

Moku virus detection in honey bees, Belgium, 2018.

We report the detection of Moku virus in honey bees (Apis mellifera) collected in 2017 from hives with a history of attacks by invasive Asian hornets (Vespa velutina nigrithorax) in Belgium. End 2016, Moku virus was reported in Asian hornets from the same area. In addition, the Moku virus was already present in historical samples of bees collected in 2013, that is, 2 years after the official first detection of Asian hornets in the same area of Belgium.

Time-to-death approach to reveal chronic and cumulative toxicity of a fungicide for honeybees not revealed with the standard ten-day test.

Synthetic fungicides are pesticides widely used in agriculture to control phytopathogenic fungi. The systemicity, persistency and intense application of some of these fungicides, such as boscalid, leads to long periods of exposure for honeybees via contaminated water, pollen and nectar. We exposed adult honeybees in the lab to food contaminated with boscalid for 33 days instead of the standard 10-day test.

The challenges of predicting pesticide exposure of honey bees at landscape level.

To evaluate the risks of pesticides for pollinators, we must not only evaluate their toxicity but also understand how pollinators are exposed to these xenobiotics in the field. We focused on this last point and modeled honey bee exposure to pesticides at the landscape level. Pollen pellet samples (n = 60) from 40 Belgian apiaries were collected from late July to October 2011 and underwent palynological and pesticide residue analyses.

Honeybee colony disorder in crop areas: the role of pesticides and viruses.

As in many other locations in the world, honeybee colony losses and disorders have increased in Belgium. Some of the symptoms observed rest unspecific and their causes remain unknown. The present study aims to determine the role of both pesticide exposure and virus load on the appraisal of unexplained honeybee colony disorders in field conditions.