Evaluating the efficacy of two insect detection methods with <i>Riptortus pedestris</i> (Hemiptera: Alydidae): portable harmonic radar system and fluorescent marking system

Abstract

BACKGROUND: Although portable harmonic radar system and fluorescent marking system are two widely used detection methods, their comparative effectiveness has not been studied. Therefore, we first tested the applicability of fluorescent marking system on Riptortus pedestris (Hemiptera: Alydidae). Then, we evaluated the efficacy of the two methods used either alone or combined in a grass field and bean field, varying with complexity, during day and night. RESULTS: Fluorescent marking did not affect the behavior or fitness of Riptortus pedestris except for vertical walking, while allowing the detection from >25 m when paired with a handheld laser. Generally, the portable harmonic radar system and both methods combined were more successful in sample detection, although the fluorescent marking system in the bean field at night was as competitive as the two. Combining both methods made sample retrieval easier at night than the portable harmonic radar system. Nevertheless, the total detection time showed a large variance across the methods. CONCLUSION: The portable harmonic radar system can be an effective detection method in either landscape during both day and night. Furthermore, the fluorescent marking system can be a reliable tool at night as well. Lastly, combining both methods can improve the night detection. © 2018 Society of Chemical Industry.