Laboratory evaluation on a potential birth control diet for fruit fly sterile insect technique (SIT)

- A potential birth control diet using lufenuron for fruit fly SIT is evaluated in the laboratory.
- Evaluation is based on survival, mating, fertility, and proteome analysis.
- Diet is fed to adults for initial 7 d to induce sterility and then switch to control diet.
- Fertility is suppressed up to 91% in 41 days, mortality and mating were not seriously affected.
- ABD-4 protein was down-regulated and Pbprp protein was up regulated after lufenuron treatment.

Sterile insect technique (SIT) is one of the most effective fruit fly control technologies. Irradiation has been used to sterilize male fruit flies before release to the field to compete with the wild males for females. Imagine an environmental and cost effective method using a rearing diet that can make insects sterile indefinitely, by feeding for 7 days before release. This could replace costly irradiation process. A potential birth control diet was evaluated on fertility, mating, survival, and protein analysis for fruit fly species in Hawaii. Insects were continuously fed an agar diet with lufenuron (LFN) for 7 d after emergence and then switched to a control diet to simulate the actual field condition. The influence on egg hatch was dose dependent. With dose of 2-4 mg/g in the diet, egg hatch from LFN-fed was almost 100% suppressed for 24 experimental days if adults of Ceratitia capitate (Widemann), Bactrocera dorsalis (Hendel), and B. latifrons (Hendel) continued to feed on LFN diet. B. cucurbitae (Coquillett) was not affected by LFN. However, egg hatch from LFN fed B. latifrons and B. dorsalis were suppressed for at least 2 weeks after switching to the control diet at 7 d. Egg hatch did not recover > 4% up to 24 d. Proteome analysis revealed that ABD-4 protein was under expressed by 70-83% on LFN fed females and males of B. latifrons and B. dorsalis while Pbprp2 protein was significantly over expressed by 6-12 fold on LFN fed males only. These two proteins were not expressed in C. capitata and B. cucurbitae. Therefore, this report focused more on B. latifrons and B. dorsalis. This finding suggested a great potential for one alternative to sterilize fruit flies for SIT without irradiation.

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