Effects of some insecticides used for dressing corn seeds on Metcalfa pruinosa.
In a maize area of the Friuli plain (northeastern Italy), where Metcalfa pruinosa infestation was very high, an experiment was conducted to verify if the decrease of M. pruinosa populations was related with the maize seed dressing with new insecticides. Mortality of M. pruinosa was monitored on maize plants grown from seeds dressed with the active ingredients imidacloprid (Gaucho 350FS), fipronil (Regent) and thiamethoxam (Cruiser 350FS) and from untreated seeds. Leaves of maize plants were also periodically collected to verify the persistence of the active ingredients. On the treated plants, the mortality of M. pruinosa was usually higher than on the untreated plants but the differences were not significant. At 70 days after sowing, it could not be possible to detect the active substances on the plants.