Longevity of Mass-Produced Bactrocera tryoni (Diptera: Tephritidae) Held without Food or Water

The sterile insect technique is used to manage or control fruit flies throughout the world. The technique relies on large scale production before delivery to release managers. As part of the mass production phase, there are many quality control tests to demonstrate and maintain high quality pupae and flies. One highly desirable characteristic is adults with a long life so that these adults can reach sexual maturity and sterile males mate with wild fertile flies in the field and thus produce no viable offspring. Originally longevity was assessed allowing adults to have unlimited access to food and water. As quality and longevity increased, this methodology added significantly to workload and space demands and many facilities moved to testing longevity under stress where no food or water was provided. Here we examined >27,000 Queensland fruit fly Bactrocera tryoni (Froggatt) from 160 weekly production batches from July 2004 to October 2009 where flies were not provided food or water. The mean longevity was 54.4 plus or minus SE hours. Longevity was significantly shorter from August to March, and the longevity was significantly longer in June. Longevity was not related to pupal weight, contrary to expectations. Weights were significantly lower in June and highest in summer.