Effect of a combined methyl bromide fumigation and cold storage treatment on Cydia pomonella (Lepidoptera: Tortricidae) mortality on apples

Mortality responses of Cydia pomonella (L.) 1-d-old eggs and diapausing 5th instars to methyl bromide fumigation at 24 gm(-3) for 2 h, followed by cold storage at a range of temperatures (0.5-10 degrees C) were determined on 'Red Delicious' and 'Granny Smith' apples. The 1-d-old eggs were more tolerant to the combined treatment than were diapausing 5th inst,rs. Times for 99% mortality (LT(99)s) in cold storage (0.5-4 degrees C) following the fumigation treatment varied between 11.9 d (0.5 degrees C) and 12.8 d (4 degrees C) and were not significantly different. LT99 for 1-d-old eggs in cold storage only varied between 19.4 d (4 degrees C) and 26.7 d (0.5 degrees C) and were not significantly different. These results indicate that a quarantine protocol of fumigation with 24 gm(-3) methyl bromide for 2 h, followed by cold storage between 0.5 degrees C and 4 degrees C for 25 d. provides a high level of quarantine security.