ADHERENT MALATHION FLOUR GRANULES AS AN ENVIRONMENTALLY SELECTIVE CONTROL FOR CHEWING INSECT PESTS OF DENT CORN EARS - INSECT CONTROL

In a small-plot field study, malathion formulated in pregelatinized co rn flour as granules at 0.1% was hand applied at a rate of 11.1 kg/ha of granules (0.011 kg [AI]/ha) of granules in 1992 and 1993. Control o f Carpophilus lugubris Murray and Helicoverpa zea (Boddie) with ii sin gle treatment of the granules was generally equivalent to that seen wh en a commercial formulation of malathion was applied in 5 sprays at a rate of 1.1 kg (AI)/ha (1 lb [AI]/acre) DPT spray. In 1994 and 1995, 1 % malathion granules at 11.1 kg/ha of granules significantly reduced c orn ear insect pests in 2 different corn varieties. No significant eff ect on coccinellid or Orius spp, numbers was noted compared with untre ated plots when the malathion granules were used. Over the top treatme nts of 0.1-10% granular malathion at 11.1 kg/ha of granules were less effective in controlling ear feeding insects at another site in 1994 c ompared with the multiple sprays of malathion applied to the ear zone. However, when granules were applied at ear level in 1995, equal or gr eater control of ear-feeding insects compared with the conventional ma lathion sprays was noted, depending on the level of active ingredients in the granules. All active ingredients rates of granules had no sign ificant effect on coccinellids compared with untreated plots in 1995, but the conventional malathion sprays killed up to 95% of the coccinel lids. When properly applied, these adherent granules should provide ac ceptable control of many ear-feeding insects in field corn, be more se lective toward predators. and use loa er levels of active ingredient c ompared with conventional malathion sprays.