Effects of transit temperature on export concern pests

Bean thrips (Caliothrips fasciatus), California red scale (Aonidiella aurantii), and several species of mites, namely, Brevipalpus spp., Lorryia formosa, Tarsonemus bakeri can be found on citrus at the time of harvest and are non-damaging to citrus. However, these species are not present in countries that import citrus and therefore, are export concern in California grown citrus . Prior studies have suggested that an 18 to 24-day transit storage at 37°F (cold) affects bean thrips survival. We evaluated the effects of low temperatures on survival of bean thrips, California red scale and Brevipalpus mites. Exposure from 35 to 41°F caused >95% mortality of bean thrips within 3-week storage. Additionally, when the temperature was lowered to 31°F, it only took 10 days to kill bean thrips. We also evaluated the effects of transit temperature California red scale and flat mites, Cold alone for 3 weeks resulted in >99% mortality for flat mites, whereas California red scale control was achieved in less than 2 weeks. Results show that storage temperature during transit has adverse effect on bean thrips, California red scale, and flat mites.  Future research will focus on exploring the effects of combined treatments using different fumigants and storage time combinations to reduce treatment exposure time.