Comparative response to packing procedures of two Anastrepha ludens strains: application in the sterile insect technique

The new desiccation resistant (DR) strain of Anastrepha ludens Loew differs in its life-history traits from the non-selected strain (NS). Given the innate resistance of DR flies to stressors, it is necessary to determine the packing and shipment conditions for their use in the Sterile Insect Technique (SIT). First, we used pupae to evaluate the interaction of hypoxia period (12, 24, and 36 h) and temperature (15.3 (± 0.9), 19.5 (± 1.0), 25.5 (± 0.6), and 30.1 (± 0.5) oC). Second, adults were exposed to densities of 1.0, 1.3, and 1.5 flies/cm2 and chilling periods of 0, 3, and 5 h. We observed a negative relationship of emergence and flight ability with hypoxia period and temperature in both strains. Flies showed the most detrimental effects when exposed to 36 h of hypoxia and 30oC. Interestingly, knock-down time decreased as male density increased, but when chilling time increased, recovery time also increased. Both chilling time and male density had negative effects on male weight. Chilling time reduced male survival when exposed to desiccation, while both chilling time and male density decreased male survival under starvation conditions. Negative effects on number of matings were observed only on the first day after chilling but not on the following days. We found that DR flies survive approximately twice as long as flies from the NS strain when exposed to starvation or desiccation stressors. We discuss our results on the basis of the potential use of DR flies in SIT programmes