PRE AND POST-EMERGENCE INSECTICIDES IN MAIZE (Zea mays L.) ASSOCIATED WITH SEED TREATMENT ON Dichelops melacanthus (DALLAS) (HEMIPTERA: PENTATOMIDAE)

Dichelops melacanthus (Dallas) (Hemiptera: Pentatomidae) is an important pest of many crops insouthern Brazil, that feed and cause damage to young plants of maize (Zea mays L.) and wheat (Triticum spp.). Thespraying of insecticide with herbicide to weed control has become a common practice to control this bug in the northand west region of Paraná State. In order to investigate strategies for bug management, the efficiency of thiametoxam+ lambdacialotrina and methamidophos was evaluated, sprayed on maize at pre and post-emergence, with and withoutseed treatment (ST). In the group without ST, insecticide spraying at pre-emergence presented small or no effect onD. melacanthus, even with added attractive (soy milk and salt). Insecticide spraying at post-emergence showed a goodcontrol of D. melacanthus, comparable to the ST, although not sufficient to reduce damage. In the group with ST,pre-emergence application was not effective in controlling the insect. Post-emergence sprays associated to ST reached80% of control.. Insecticide spraying at post-emergence in addition to ST was significant at the present experimentalconditions, although is only justified if the cost/benefit ratio is satisfactory.