Seasonal changes in efficiency of traps used in the lure and kill method for the control of Bactrocera oleae

The efficiency of two types of traps (Eco-Trap (Vioryl, Greece) and Attract & Kill (AgriSense, UK)) used in the lure and kill system for the control of the olive fruit fly, was studied by laboratory and field experiments performed in Sardinia during the period 2003-2006. The attraction power of devices containing ammonium bicarbonate turned out to be higher in summer and considerably lower in autumn. Laboratory bioassays with Ceratitis capitata adults showed a good knockdown power for about 4 months for both kinds of traps but a progressively decreased lethal effect during the exposition period in the field. The two types of devices (100 per hectare), used in field control trials against Bactrocera oleae, were very efficient in September, when a significant reduction in ovipositions was noticed, whereas they became less effective in October. Not even the addition of 50 or 100 more Eco-Traps/ha in September was always able to determine a greater reduction in fly infestation.