“…Dietary metabarcoding has been used to determine the trophic interactions of trapped invertebrates (Huszarik et al, 2023), but much like similar methods, cross-contamination within the trap results in many false positive detections (Athey, Chapman and Harwood, 2017), requiring surface sterilisation (e.g., with bleach) to reduce these instances (Miller-ter Kuile, Apigo and Young, 2021). Bulk sample metabarcoding has, however, been applied very successfully; for example, to monitor and assess ecosystem restoration (Fernandes et al, 2019;Van Der Heyde et al, 2022), and beetle responses to human disturbances in forests (Liu, Baker, et al, 2020). Ethylene glycol is often used as a killing agent in studies combining metabarcoding and pitfall traps (Hohbein and Conway, 2018), with subsequent washing of samples prior to molecular analysis (e.g., with ethanol or water ;Fernandes et al, 2019;Van Der Heyde et al, 2022).…”