Selection of colour of sticky trap for monitoring adult bean thrips, Caliothrips fasciatus (Thysanoptera: Thripidae).

Adult bean thrips, Caliothrips fasciatus (Pergande), overwintering inside the navel of navel oranges shipped from California to Australia, are an actionable pest for the importing country, i.e. infested lots are fumigated with methyl bromide. Strict quarantine regulations regarding C. fasciatus prompted studies on the best colour sticky trap that might be used to monitor for bean thrips populations in the vicinity of California citrus groves prior to harvesting fruit for export. Preliminary experiments identified the most attractive trap of each of four colours (blue, green, white, yellow) commonly used to sample adult Thysanoptera. Three trials of a field study were conducted, comparing C. fasciatus capture on the best card of each colour using asparagus ferns naturally infested with high levels of this pest. Based on significantly higher catch on green sticky cards, this colour trap is recommended for potential use in California's bean thrips mitigation plan designed to reduce thrips levels on citrus exported to Australia.