Double-blind validation of alternative wild bee identification techniques: DNA metabarcoding and in vivo determination in the field

Over the past few decades, several investigations around the globe have reported alarming declines in the abundance and diversity of bee species. The success of effective conservation strategies targeting these important pollinators relies heavily on accurate biodiversity assessments. The shortage of taxonomic experts and the escalation of the ongoing biodiversity crisis call for the development of alternative identification tools to implement efficient monitoring programs. The validation of such techniques is crucial to ensure that they provide results comparable to those of traditional morphotaxonomy. Here we performed two double-blind experiments to evaluate the accuracy of a pair of new techniques used for wild bee identification: DNA metabarcoding and in vivo identification in the field. The methods were tested on sets of wild bees from Germany and their results compared against evaluations done by panels of bee experts using traditional morphotaxonomy. On average the congruency of species identification between metabarcoding and morphotaxonomy was 88.98% across samples (N = 10), while in vivo identification and morphotaxonomy were 91.81% congruent (N = 7) for bees considered feasible for in vivo identification in the field. Traditional morphotaxonomy showed similar congruencies when compared to itself: 93.65% in the metabarcoding study and 92.96% in the in vivo study. Overall, these results support both new methods as viable alternatives to traditional microscopy-based assessment, with neither method being error-free. Metabarcoding provides a suitable option to analyze large numbers of specimens in the absence of highly trained taxonomic experts, while in vivo identification is recommended for repeated long-term monitoring, and when working in areas where the sampling of individuals could threaten local populations of endangered wild bee species. Further research is still needed to explore the potential of both techniques for conservation management and wildlife monitoring, as well as to overcome their current limitations as taxonomic tools

Supplementary material 5 from: Herrera-Mesías F, Bause C, Ogan S, Burger H, Ayasse M, Weigand AM, Eltz T (2022) Double-blind validation of alternative wild bee identification techniques: DNA metabarcoding and in vivo determination in the field. Journal of Hymenoptera Research 93: 189-214. https://doi.org/10.3897/jhr.93.86723

Supplementary file

Crop Diversification in Viticulture with Aromatic Plants: Effects of Intercropping on Grapevine Productivity in a Steep-Slope Vineyard in the Mosel Area, Germany

The effects of intercropping grapevine with aromatic plants are investigated using a multi-disciplinary approach. Selected results are presented that address the extent to which crop diversification by intercropping impacts grapevine yield and must quality, as well as soil water and mineral nutrients (NO3-N, NH4-N, plant-available K and P). The experimental field was a commercial steep-slope vineyard with shallow soils characterized by a high presence of coarse rock fragments in the Mosel area of Germany. The field experiment was set up as randomized block design. Rows were either cultivated with Riesling (Vitis vinifera L.) as a monocrop or intercropped with Origanum vulgare or Thymus vulgaris. Regarding soil moisture and nutrient levels, the topsoil (0–0.1 m) was more affected by intercropping than the subsoil (0.1–0.3 m). Gravimetric moisture was consistently lower in the intercropped topsoil. While NO3-N was almost unaffected by crop diversification, NH4-N, K, and P were uniformly reduced in topsoil. Significant differences in grapevine yield and must quality were dominantly attributable to climate variables, rather than to the treatments. Yield stabilization due to intercropping with thyme and oregano seems possible with sufficient rainfall or by irrigation. The long-term effects of intercropping on grapevine growth need further monitoring.ISSN:2077-047

Supplementary material 4 from: Herrera-Mesías F, Bause C, Ogan S, Burger H, Ayasse M, Weigand AM, Eltz T (2022) Double-blind validation of alternative wild bee identification techniques: DNA metabarcoding and in vivo determination in the field. Journal of Hymenoptera Research 93: 189-214. https://doi.org/10.3897/jhr.93.86723

Supplementary file

Supplementary material 1 from: Herrera-Mesías F, Bause C, Ogan S, Burger H, Ayasse M, Weigand AM, Eltz T (2022) Double-blind validation of alternative wild bee identification techniques: DNA metabarcoding and in vivo determination in the field. Journal of Hymenoptera Research 93: 189-214. https://doi.org/10.3897/jhr.93.86723

Supplementary file

International scientists formulate a roadmap for insect conservation and recovery

Plant science