Comparison of Two Traps for Monitoring California Red Scale (Hemiptera: Diaspididae)

Abstract

Abstract California red scale, Aonidiella aurantii (Maskell) (Hemiptera: Diaspididae) is an economically important pest of citrus. In many cases, California red scale pest management is based on pheromone trap captures of males during their flight period. In California, where this study was conducted, California red scale pheromone traps are deployed from Mar until the end of Oct, at densities of 2 to 4 traps per 4 ha. Therefore, monitoring for California red scale represents a significant time expenditure for orange growers, and improved monitoring tools would be beneficial. This study was conducted to compare the efficacy of 2 California red scale trap designs during a 7-mo-long field study conducted in a commercial navel orange grove. In particular, we compare trap captures, and the occurrence of management thresholds, between a double-sided California red scale trap and a single-sided California red scale trap, both baited with commercial California red scale lures. The single-sided California red scale trap was incorporated into an internet-of-things platform designed for automated or remote monitoring. Mean trap captures, the occurrences of management thresholds, and the seasonal phenology of capture were similar between both trap types. Importantly, the proportion of traps reaching management thresholds were not significantly different between trap types. These results suggest that both trap types can be used in a similar fashion to monitor California red scale in commercial settings using currently recommended monitoring guidelines.