Le Trappole a feromoni nella lotta alPrays oleaebern.

Researches carried out from 1980 to 1983 in Sardinian oil-producing olive groves investigatedPrays oleaeinfestations by examining weekly 300-600 flower clusters or newly-formed olives. The trend of male catches was examined weekly (in some groves daily) using 3-6 pheromone traps in each grove. The daily catches revealed the influence of climatic factors, trends being similar in the same zone even between groves distant from each other. A strict correspondence was observed between catches, each in sect generation development and plant vegetative stages. Anthophagous generation catches proved to be the most numerous (June-July), and carpophagous generally the least. Peak oviposition occurred on the drupes when the newly·formed olives began to enlarge, and anthophagous male catches were maximum. Thus, pheromone traps offer an excellent means of establishing the correct time for insecticidal treatment against the eggs and newly-hatched larvae of the carpophagous generation. No correlation was found between anthophagous male catches and oviposition on the olives nor between the number of eggs and larvae boring into the kernel. Up to the moment, therefore, it has not been possible to determine an intervention threshold based on pheromone trap captures.