Lara B. Ribeiro, Samuel R. França, Daniel Costa Nogueira, Monique Fróis Malaquias, Mariana M. F. Oliveira, Carlos Gustavo da Cruz, Flávio Lemes Fernandes
Accurate sampling is crucial for managing onion thrips. We evaluated three field techniques: tapping method, bagging method, and blue sticky trap, against direct counting as the reference standard in 30 fields. Assessment integrated relative variance (RV), economic precision (EP), cost, time, and correlation with absolute density. The blue sticky trap was the only method with adequate precision (RV=5.27%) and highest EP (135.50). Although the bagging method was cheapest per sample, the blue sticky trap offered the best field cost-benefit ($3.64/ha) and strongest correlation (R²=0.79), establishing it as the most reliable tool for IPM monitoring.