The Effect of Long-Distance Transportation on the Fitness of Irradiated False Codling Moth (Lepidoptera: Tortricidae) for Use in a Sterile Insect Release Program.

ABSTRACT

The effect of cold immobilization and long-distance transport of irradiated Thaumatotibia leucotreta (Meyrick) on the flight ability of male (♂) and female (♀) moths, the longevity of male and female moths, and the realized fecundity of mating pairs CIM (chilled irradiated moths) ♀ × CIM♂, CIM♀ × NIP (nonirradiated pupae) ♂, NIP♀ × CIM♂, and NIP♀ × NIP♂ was examined to improve application of the sterile insect technique (SIT). Adult moths treated with 150 Gy of gamma radiation were immobilized with cold temperature between 4 and 6°C inside a polyurethane cooler box and transported for 12 h by road from Citrusdal, Western Cape Province, to Addo, Eastern Cape Province. Nonirradiated moths were transported as pupae inside a cardboard tray and removed by hand after which male and female pupae were separated and placed inside containers for eclosion. Male and female moths were individually placed inside petri dishes to determine longevity or paired with irradiated and nonirradiated counterparts to evaluate realized fecundity before incubation in 100% darkness at 25°C and 75% relative humidity. Flight tests were conducted indoors at 25°C by release of individual moths per hand. A significant decrease in flight ability and longevity of irradiated false codling moth was found after handling, cold immobilization, and transport, although critically, realized fecundity was not affected. Because of the impact of long-distance transport on quality of the released insects as well as the efficacy of SIT, comprehensive protocols for this critical step in the process need to be developed for a pestiferous insect with phytosanitary status such as false codling moth.