Metabarcoding and eDNA for insect conservation

Environmental DNA (eDNA) samples and metabarcoding studies have emerged as transformative sampling methods and techniques with potential in the field of insect conservation. eDNA refers to genetic material shed by organisms into their environment. By extracting and sequencing this DNA, it is possible to detect the presence of target species without the need for direct observation, capture, or destructive sampling. Metabarcoding is a technique used to quantify multiple species in a biological sample simultaneously by sequencing specific DNA regions, often called barcodes. When combined, eDNA and metabarcoding provide a powerful approach for comprehensive insect biodiversity assessments. This chapter provides background on eDNA and metabarcoding and the implications for insect conservation. An overview of the methodologies involved in eDNA and metabarcoding studies is provided, as well as a discussion on the strategies and considerations involved in collecting eDNA samples, utilising the proper controls, experimental work involved, and subsequent data analysis in metabarcoding studies. Cases are given as examples of practical applications of eDNA and metabarcoding in insect conservation studies and discuss the challenges related to standardisation of sampling protocols and optimisation of DNA extraction methods, as well as establishment of reliable reference DNA databases.