LOW-TEMPERATURE STORAGE AS A POSTHARVEST TREATMENT TO CONTROL PSEUDOCOCCUS-AFFINIS (HOMOPTERA, PSEUDOCOCCIDAE) ON ROYAL GALA APPLES

Royal Gala apples infested by the obscure mealybug, Pseudococcus affin is (Maskell), were stored at 0, 4, and 7 +/- 0.5 degrees C for various durations from 0 (control) to 126 d. As storage temperature decreased , the estimated times for 50 and 99% P. affinis mortality (LT50 and LT 99, respectively) decreased. Mean LT50 values for the different life s tages tested increased in the following order: 1st instar < 2nd-3rd in star less than or equal to female adult. This LT50 pattern became more evident with increasing temperature. At both 4 and 7 degrees C, mean 1st-instar LT99 values were less than those for 2nd-3rd instars and fe male adults. Storage at 0 degrees C resulted in the lowest mean LT(99) s for 1st instars, 2nd-3rd instars, and female adults (16.1, 19.0, and 18.9 d, respectively). A large scale test storing 6,403 1st instars, 3,050 2nd-3rd instars, and 3,028 female adults at 0 degrees C for 42 d resulted in complete mortality.