Assessing mating performance of male Glossina pallidipes (Diptera : Glossinidae) using a walk-in field cage

To monitor the quality of male tsetse for use in the sterile insect techniq ue (SIT), a field cage test was developed and evaluated. Mating competitive ness was tested with male Glossina pallidipes Austen that emerged from pupa e stored for different periods at 15 degreesC. Control males emerged from p upae stored at 23-24 degreesC and emerged at 26.5 degreesC. Each sample of test males was divided into two groups with one group being irradiated at 1 20 Gy; the other group was not irradiated. More than 70% of the maximum pos sible number of mating pairs occurred in all tests. Males emerged from pupa e kept at low temperature and then irradiated formed a greater proportion o f mating pairs than the controls. Males emerged from pupae kept at 15 degre esC generally started mating more quickly than the standard colony males al though there was no significant difference. Insemination rates were above 9 9%. Pooled data indicated that mean spermathecal values for females mated w ith irradiated males were significantly lower than for control males. The d uration of copulation varied significantly between treatment groups and was significantly longer for irradiated male flies; there was no correlation b etween duration of copulation and mean spermathecal value.