Dispersal of marked and released Lobesia botrana in a small isolated vineyard and the effect of synthetic sex pheromone on moth movement

Abstract

Mobility of moths at the time of implementation of the mating disruption method, against Lobesia botrana, requires to maintain, around the vineyards a border area. Its width depends of the dispersal ability of egg laying females. This dispersal was studied by use of the « mark release capture » insect technique. Laboratory reared insects were colored externally or internally and released in the middle of a food trap network. A small surface around one release station was equiped with pheromone dispensers. Two main results for setting up the insect control were established : 1 - the virgin females were not very mobile and were only captured in low numbers by the food traps. Consequently it is impossible to use this trapping technique to evaluate the sucess of mating disruption and the hypothesis that females leave the vineyard impregnated with pheromone in order to be inseminated outside is improbable. 2 - the dispersal of females within the vineyard exceeds rarely 80 m. This value seems to define width of the protection area around the vineyards treated by the mating disruption technique, that are close to other highly infested vineyards.