Three steps towards comparability and standardization among molecular methods for characterizing insect communities

Abstract

Molecular methods are currently some of the best-suited technologies for implementation in insect monitoring. However, the field is developing rapidly and lacks agreement on methodology or community standards. To apply DNA-based methods in large-scale monitoring, and to gain insight across commensurate data, we need easy-to-implement standards that improve data comparability. Here, we provide three recommendations for how to improve and harmonize efforts in biodiversity assessment and monitoring via metabarcoding: (i) we should adopt the use of synthetic spike-ins, which will act as positive controls and internal standards; (ii) we should consider using several markers through a multiplex polymerase chain reaction (PCR) approach; and (iii) we should commit to the publication and transparency of all protocol-associated metadata in a standardized fashion. For (i), we provide a ready-to-use recipe for synthetic cytochrome c oxidase spike-ins, which enable between-sample comparisons. For (ii), we propose two gene regions for the implementation of multiplex PCR approaches, thereby achieving a more comprehensive community description. For (iii), we offer guidelines for transparent and unified reporting of field, wet-laboratory and dry-laboratory procedures, as a key to making comparisons between studies. Together, we feel that these three advances will result in joint quality and calibration standards rather than the current laboratory-specific proof of concepts. This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.

Measuring the state of aquatic environments using eDNA—upscaling spatial resolution of biotic indices

“…Despite the large improvements in understanding eDNA metabarcoding in recent years, the fact that these advancements have not leaped from research to the application of DNA-based monitoring methods could be attributed to the explosion in method development. Rapid methodological advances have brought many possible avenues of application, but also lack of standardisation across the field [26][27][28]. Much of the early eDNA method development focused on the 'renovation' of conventional bioindicator groups for molecular-based approaches (e.g.…”

Towards a toolkit for global insect biodiversity monitoring

“…However, the rapid development of molecular methods has resulted in methodological sprawl, raising pleas for a much-needed standardization (and at least comprehensive reporting) of methods. The adoption of general guidelines is clearly needed to make data comparable, and Iwaszkiewicz-Eggebrecht et al [ 34 ] make an important contribution to make this happen. Another key challenge for current DNA-based methods is the reliable assignment of DNA-sequences to established taxonomy, which is crucial, since ecological information and traits are tied to taxonomic names.…”

“…Iwaszkiewicz-Eggebrecht et al . [ 34 ] and Roy et al . [ 42 ] make important steps towards establishing standards for molecular monitoring and computer vision, respectively.…”