Biology subjects

Sorg, M.

Publications and source records attributed to Sorg, M..

4 recordsLinked to original sources

bioRxiv2022

A universal insect trait tool (ITT, v1.0) for statistical analysis and evaluation of biodiversity research data

We present a unique data set of trait information for 586 insect families in Central Europe, covering the largest known part of described species (over 34,000 species). Life history information and major functional traits were evaluated with fuzzy coding and weighted according to the number of known species in Germany. An overall analysis of the German insect fauna is given and the data set is exemplarily applied to metabarcoding results of malaise trap samples. Due to the high functional and taxonomic diversity in insects, further developments and refinements of traits to be included will be an ongoing process with advancements of upcoming database versions to be subsequently published.

ecology↗

bioRxiv2022

Recommendations for tissue homogenisation and extraction in DNA metabarcoding of Malaise trap samples

With increased application of DNA metabarcoding in fast and high-resolution biodiversity assessment, various laboratory protocols have been optimised in recent years and their further evaluation is subject of current research. Homogenisation of bulk samples and subsequent DNA extraction from destructed tissue is one way of starting the metabarcoding process. This essential step in the protocol can either be conducted from wet sample material (e.g. bulk insect samples) soaked in fixative or from completely dried individuals. While the latter method appears to produce more consistent results, it is time consuming and more prone to cross-contamination. We tested both homogenisation approaches with regard to time efficiency and biodiversity assessment of complex arthropod bulk samples, in particular how the amount of processed tissue affects taxon recovery. Both approaches reveal similar taxa compositions and detect a similar total OTU diversity in a single extraction reaction. Increased amounts of tissue used in DNA extraction improved OTU diversity detection and recovered particularly specific low-biomass taxa, making this approach valuable for samples with high biomass and/or diversity. Due to less handling time and lower vulnerability for cross-contamination we recommend the processing of wet material when sample homogenisation is applied.

molecular biology↗

bioRxiv2021

Metabarcoding malaise trap plant components enables monitoring the diversity of plant-insect interactions

The declines observed in insect abundance and diversity in the past decades has also been observed in plants, and these events are most certainly correlated. Rapid largescale biomonitoring of both plants and insects can help monitor these changes and inform decisions for land management and species protection. Malaise traps have been used for nearly 80 years for passive insect sampling of primarily flying insects, and when they enter these traps, they carry the fragments of the plants they have visited, either as plant fragments and pollen on the body surface, or as digested food material in gut contents. DNA metabarcoding is a potential method to identify these plant traces in the ethanol of the malaise bottles, which is not possible with traditional microscopy. Metabarcoding could offer more insight into what plants insects are directly interacting with at a given time, and allow for the detection of rare plants, and neophyte species visited by insects. This study, to our knowledge, is the first examination of DNA metabarcoding plant traces from Malaise trap samples, we examine 105 samples from 21 sites throughout Germany collected in a 2-week period in May of 2020. Here we report on the feasibility of sequencing these sample types, analysis of the resulting taxa, the usage of cultivated plants by insects near nature conservancy areas, and the detection of rare and neophyte species.

molecular biology↗

bioRxiv2020

Pooling size sorted malaise trap fractions to maximise taxon recovery with metabarcoding

O_LISmall and rare specimens can remain undetected when metabarcoding bulk samples with a high size heterogeneity of specimens. This is especially critical for malaise trap samples, where most of the biodiversity is often contributed by small specimens. How to size sort and in which proportions to pool these samples has not been widely explored. We set out to find a size sorting strategy that maximizes taxonomic recovery but remains highly scalable and time efficient. C_LIO_LIThree 3 malaise trap samples where size sorted into 4 size classes using dry sieving. Each fraction was homogenized and lysed. The corresponding lysates were pooled to simulate samples never sorted, pooled in equal proportions and in 4 different proportions favoring the small size fractions. DNA from the pooled fractions as well as the individual size classes were extracted and metabarcoded using the FwhF2 and Fol-degen-rev primer set. Additionally wet sieving strategies were explored. C_LIO_LIThe small size fractions harbored the highest diversity, and were best represented when pooling in favor of small specimens. Not size sorting a sample leads to a 45-77% decrease in taxon recovery compared to size sorted samples. A size separation into only 2 fractions (below 4 mm and above) can already double taxon recovery compared to not sorting. However, increasing the sequencing depth 3-4 fold can also increase taxon recovery to comparable levels, but remains biased toward biomass rich taxa in the sample. C_LIO_LIWe demonstrate that size fractionizing bulk malaise samples can increase taxon recovery. The most practical approach is wet sieving into two size fractions, and proportional pooling of the lysates in favor of the small size fraction (80-90% volume). However, in large projects with time constraints, increasing sequencing depth can also be an alternative solution. C_LI

molecular biology↗