Testing effectiveness of the maize seeds treatment concerning maize leaf weevil (Tanymecus dilaticollis Gyll) control, in laboratory conditions

Abstract

Maize leaf weevil (Tanymecus dilaticollis Gyll) is an economically important pest of maize crop in south and south-east of the Romania. The insect is favored by high temperature and drought when maize plants are in first vegetation stages. In this assessment it has studied effectiveness of some insecticides used like seed treatment in laboratory conditions, in plastic pots sowed with treated and untreated maize seeds. Each pot was infested with adult insects collected from the field after plant emergence. Insects mortality were higher in case of seeds treated both with thiametoxan (Cruiser 350 FS) and clothianidin (Poncho 600 FS) active ingredients. Seeds treated with tiacloprid active ingredient (Sonido) provide lower mortality values. Attack intensity was lower in case of seeds treated both with thiametoxan (Cruiser 350 FS) and clothianidin (Poncho 600 FS) active ingredients and higher in case of treated seeds with tiacloprid active ingredient (Sonido). Seeds treatment provides satisfactory protection for maize plants in first vegetation stages against Tanymecus dilaticollis. Bioassays in laboratory conditions are a complementary method with field testing and provide useful information regarding insect behavior.