Mediterranean Fruit Fly Ceratitis capitata (Diptera: Tephritidae) Eggs and Larvae Responses to a Low-Oxygen/High-Nitrogen Atmosphere

SIMPLE SUMMARY: Many chemicals have been removed from registration for the postharvest treatment of insect pests due to consumer/environmental safety and phytotoxicity. There is very limited operation for international trade purposes, particularly for management of Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) on harvested fruit. Therefore, the non-chemical method is being considered for postharvest treatment of fruit. This study explored and evaluated Medfly response to low-oxygen and high-nitrogen treatment. The results will guide the development of a novel postharvest strategy and the approach to controlling this destructive fruit fly and other pests. ABSTRACT: The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most damaging horticultural insect pests. This study used a low-oxygen/high-nitrogen bioassay to control C. capitata. Two low-oxygen treatments were applied (0.5% O(2) + 99.5 N(2) and 5% O(2) + 95% N(2)) to C. capitata eggs and 1st, 2nd and 3rd instar larvae from 0 to nine days on a carrot diet at 25 °C; 70—75% RH. The pupariation, adult emergence, and sex ratios of survived flies were examined. The results demonstrate that increased mortality of all tested life stages correlated with increased exposure times at both levels of low-oxygen treatments. Complete control of eggs was achieved after eight days and nine days for larvae using 0.5% O(2) at 25 °C; 70–75% RH. The 3rd instar was the most tolerant stage, while the egg was the most susceptible stage to the low-oxygen environment. There were no significant differences in sex ratios between emerged adults after low-oxygen and control treatments. The present work demonstrates and confirms the mortalities of C. capitata caused by low-oxygen treatment, which may help develop new postharvest strategies to control this destructive fruit fly pest.