Field OPS & Areas
– Host plant management
SIT is an integrated strategy; sterile fruit flies cannot do the job alone. Success with an SIT programme is dependent on being able to maintain a high ratio of sterile males to wild males in the field, in order to minimize the chance of a wild male mating with a wild female.
Good orchard/vineyard hygiene is essential in any fruit fly programme. Fallen fruit often contains fruit fly eggs or larvae which will help sustain infestation in orchards and vineyards. In vineyards, fruit fly larvae can complete their development in “na-trossies” as they dry out and become raisins. Green fruit that is stripped from trees early in the season cannot later serve as fruit fly hosts. Good hygiene in home gardens is no less important, as home gardens serve as the main reservoir of the fruit fly breeding population through the year.
All fruit fly-infested and fallen fruit must be removed and destroyed (e.g. by pulping, or placing in black plastic bags left in the sun), or buried at least 1 m deep. In vineyards, “na-trossies” are a major source of re-infestation and should be removed. Particular attention should be paid to home gardens. Where fruit trees have fruit that will not or cannot be used, this fruit should be completely stripped from the trees before it ripens and becomes attractive to fruit flies.