Control of the White Grub Liogenys fusca (Blanchard) (Coleoptera: Melolontidae) Using Insecticides on Seeds and in Soybean (Glycine max) Sowing Furrow ABSTRACT -Among soil pests that attack soybean crop, the white grubs complex has great importance during initial stage of crop development, and Liogenys fusca (Blanchard) is the most common species in Brazilian Western Central Region. The objective with this work was to evaluate the effect of some insecticides applied either to the soil or to the seed for control of L. fusca larvae in a soybean field.The study was carried out during 2006/07 crop season in Mato Grosso State, Brazil. In the furrow, the following insecticides were applied (g.ha-1): chlorpyrifos (576 and 720), endosulfan (1050), bifenthrin (40 and 60), imidacloprid (60), and fipronil (25). For seed treatment the following insecticides were applied: (g/100 kg of seeds): imidacloprid (60), clothianidin (60), fipronil (25 and 50), imidacloprid + thiodicarb (60 + 180), acephate (600) and thiamethoxam (42). Crop stand at 10 and 35 days after soybean emergency (DAE), plant height at 35 and 54 DAE and grain yield were measured to evaluate the effect of insecticides and the way of application. Chlorpyrifos (720 g.ha -1 ), endosulfan (1050) and fipronil (25), applied in the furrow, and imidacloprid (60 g.100kg -1 ), clothianidin (60) and fipronil (50), applied on seeds, provided the best initial establishment and development of the soybean crop. However there was no difference for grain yield between all insecticides applied either in soil or seeds, but these chemical treatments provided higher grain yield than the control treatment. It was concluded that insecticide application on seeds or in the furrow might be used as a strategy to larvae control of L. fusca in soybean fields. KEY WORDS -Insecta, soil pest, stand, productivity.RESUMO -Dentre as pragas de solo que atacam a soja, destacam-se as larvas rizófagas de besouros melolontídeos que podem causar danos severos nos estágios iniciais de desenvolvimento da cultura, sendo Liogenys fusca (Blanchard) (Coleoptera: Melolonthidae) a espécie mais comum na Região Central do Brasil. Objetivou-se avaliar o efeito de inseticidas aplicados nas sementes ou em pulverização no sulco de semeadura da soja visando o controle do coró L. fusca. O estudo foi conduzido durante a safra de 2006/2007, no Estado de Mato Grosso, sendo avaliados os seguintes inseticidas aplicados no sulco de semeadura: clorpirifós (576 e 720 g/ha), endosulfam (1050 g/ha), bifentrina (40 e 60 g/ha), imidacloprido (60 g/ha), fipronil (25 g/ha). Nas sementes foram avaliados os seguintes inseticidas (100 kg de sementes): imidacloprido (60), clotianidina (60), fipronil (25 e 50), imidacloprido + tiodicarbe (60 + 180), acefato (600), tiametoxam (42). Para avaliar o efeito dos inseticidas e modo de aplicação dos mesmos, avaliou-se o estande aos 10 e 35 dias após a emergência (DAE) da soja, bem como a altura das plantas aos 35 e 54 DAE e o rendimento de grãos. Clorpirifós (720 g.ha ), aplicados no sulco de ...