D3233: Staying grounded: Lowering trap placement increases beet leafhopper capture rate

Beet leafhopper (BLH; Circulifer tenellus) is a significant agricultural pest and the primary vector of a Candidatus Phytoplasma trifolii, the pathogen that causes potato purple top. Accurate estimates of BLH populations and Phytoplasma infection rates is needed for growers to make informed management decisions. BLH is typically monitored using yellow sticky cards typically hung at ground level, which catch high numbers of insects but may result in specimens not suitable for molecular detection of Phytoplasma. The capture of insects directly into a preservative (ethylene glycol) provides higher quality specimens, and may increase Phytoplasma detection rates, but preliminary studies showed very low capture rates of BLH in these traps at 1-m height. Our objective was to determine if lowering traps to ground-level increases capture rates of BLH. Traps were placed in seven replicated blocks within naturalized habitats. Each replication included a pair of 3D-printed traps and a pair of yellow sticky cards with one of each type of trap positioned at ground level, and the other at 1-meter height. Traps were monitored weekly for three weeks with three separate trials in 2020 and 2021. Results confirmed that lowering either trap to ground level significantly increases capture rates of beet leafhoppers, but sticky traps were superior to the preservative-based traps regardless of height.