Diana C. Whiting

Potential of low oxygen/moderate carbon dioxide atmospheres for postharvest disinfestation of New Zealand apples

Abstract Work on the mortality responses of four lepidopteran pests of apples in New Zealand—Epiphyas postvittana (Walker), Cydia pomonella (L.), Planotortrix octo Dugdale, and Ctenopseustis obliquana (Walker)—to low O2/moderate CO2 atmospheres is reviewed and additional data are presented. For both E. postvittana and C. pomonella, reducing the O2 concentration and elevating the treatment temperature enhanced controlled atmosphere (CA) efficacy more than did increasing the CO2 concentration. Thus at 20°C, a 0.4% O2/5.0% CO2 CA gave the most rapid kill of the mixtures tested. The order of lifestage tolerance to this CA was similar for E. postvittana, C. pamonella, P. octo, and C. obliquana i.e., fifth instar > third instar > 3-day eggs > first instar. The four species exhibited a trend of tolerance of C. pomonella > E. postvittana = P. octo = C. obliquana. An increase in the temperature to 30°C decreased the time for high mortality for all four species. However, this decrease was much greater for P. octo a...

Mortality responses of three leafroller (Lepidoptera: Tortricidae) species on kiwifruit to a high‐temperature controlled atmosphere treatment

Abstract Mortality responses of 3‐day‐old eggs and 1st, 3rd, and 5th instars of three leafroller (Lepidoptera: Tortricidae) pests, infesting kiwifruit (Actinidia deliciosa) after exposure to a high‐temperature controlled atmosphere (2% O2 with 5% CO2 at 40°C) were determined. All four life stages of Cnephasia jactatana (Walker) had similar mortality responses to controlled atmosphere (CA) treatment at the 99% mortality level. Fifth instars of Ctenopseustis obliquana (Walker) were more tolerant than the other three life stages tested. Epiphyas postvittana (Walker) showed a trend of increasing exposure time to achieve 99% mortality as development progressed. E. postvittana was more tolerant of CA treatment than C. obliquana and C. jactatana. An exposure time of 6 h resulted in control (> 99% mortality) of C. jactatana and C. obliquana however, did not control all life stages of E. postvittana. There is potential to combine a short high‐temperature CA treatment with a longer period of low‐temperature CA stor...