It drowns in the bait. Protein hydrolyzates are effective baits but make identification of the insects difficult. Ammonia salt solutions will attract olive flies and is clear so enhances insect identification. The sex ratio and egg carrying condition of females can be noted daily from such traps. Fruit samples can be taken for examination under dissecting microscope for larvae and eggs.
Stage of development is noted.
This takes a more sophisticated technician. Lure and kill traps last 5-6 months and sprays last only days or weeks. More than 5 adult flies per day per panel trap 2. Olive crop is at risk hardened pit stage 4. Flies are beginning to become sexually active as evidenced by preference to pheromone lure sticky traps vs. plain yellow traps.