Unveiling invasive insect threats to plant biodiversity: Leveraging eDNA metabarcoding and saturated salt trap solutions for biosurveillance

considered a primary pest of trees, recent studies suggest otherwise, indicating that it does not cause significant damage [30]. The above species detections highlight the utility of molecular biosurveillance to detect and prevent further spread. As in previous cases, an early warning for prompt actions can pro- foundly impact preserving biodiversity, significantly reducing economic losses and contribut- ing to Canadians’ well-being. Filter quarters vs. whole filter analysis The lack of consistent IAS eDNA detection on most filter quarters from the 2020 collection suggests a patchy distribution of eDNA on the filters. This can impact species detectability and constitute a sampling bias when using filter fragments alone for eDNA detection. Therefore, pooling extracts from all filter quarters belonging to the same sample before library prepara- tion [4, 49] or whole filter analysis is suggested for more accurate IAS detection and the most comprehensive inference of species diversity in a sampling site. Multiple biological replicates using whole filters is desirable in contrast to using filter fragments as a backup plan or for use as voucher samples for future analysis. Present species composition analysis beyond IAS rati- fied that quarters or halves alone did not necessarily reflect the species diversity of the whole filter. The latter might directly affect any molecular-based inference of species presence based on filter quarters, which can be common in the eDNA field [50–52].

Fig 6. Average species richness per 2020 sample collected, including whole and quarter filter analysis. QS and SA refer to specific 2020 sampling sites. Whole and half in silico refer to the ESV bioinformatic combinations for the entire filter and their halves from filter quarters. https://doi.org/10.1371/journal.pone.0290036.g006 PLOS ONE Unveiling invasive insect threats to plant biodiversity PLOS ONE | https://doi.org/10.1371/journal.pone.0290036 August 11, 2023 16 / 24