Automated non-lethal moth traps can be used for robust estimates of moth abundance

Abstract

O_LIRecent reports of insect decline highlight the need for extensive large-scale insect monitoring. However, obtaining abundance or species richness data at high spatial and temporal resolution is difficult due to personnel, maintenance, and post-processing costs as well as ethical considerations. Non-invasive automated insect monitoring systems could provide a solution to address these constraints. However, every new insect monitoring design needs to be evaluated with respect to reliability and bias based on comparisons with conventional methods. C_LIO_LIIn this study, we evaluate the effectiveness of an automated moth trap (AMT), built from off-the-shelf-hardware, in capturing variations in moth abundance, by comparing it to a conventional, lethal trap. Both trap types were operated five times on 16 plots from the beginning of July 2021 to the end of August 2021. C_LIO_LIMoth abundance scaled isometrically between the two trap types. Consequently, the respective seasonal patterns in abundance determined over the monitoring period were similar. C_LIO_LIThe AMT samples phenological patterns using a robust and non-lethal method. However, an initial quantitative in-field test revealed that its long-term applicability must be preceded by several adjustments to the power supply and to data transfer. Depending on the software implementation, the AMT can be used to address a broad range of research questions while also reducing both energy expenditure and the disturbance of non-target animals. C_LI