The influence of application methods on the efficacy of granular systemic insecticides used in the control of Quesada gigas (Olivier) and Dorisiana drewseni (Stål) attacking coffee (Coffea arabica) trees was studied. The trial was set up in a 6 years-old coffee cv. "Mundo Novo" plantation, planted in 3.5 X 1.5 m spacing, during 1992/1993. The experimental design used was randomized blocks, with 21 treatments replicated 4 times, each with 5 plants/ plot. The insecticides triadimenol + disulfoton 1.5% + 7.5% (26 g/tree), aldicarb 150G (10.0 g /tree), ethoprophos 100G (30.0 g/tree), phorate 5G ( 80.0 g/tree) and terbufos 5G (40.0 g/tree) were applied using four methods: manually operated knapsack applicator Mebuki TF8; throwing manually a mugfull of granules on the top of the canopy; tractor powered granule applicator, Kamaq CK2-AG, applying in furrow under the canopy; and in furrow manual application of granules. Assessment of control was carried out counting live nymphs at 70, 105 and 140 days after application, in a pit measuring 50 X 50 X 50 cm made underneath the plant canopy. The application method using the knapsack applicator and the mug showed to be the most effective (86.0 - 93.5% and 76.8 - 86.7%, respectively); application by tractor and in furrow under canopy afforded variable efficiency according to the chemical used; the performance of terbufos was the highest in reducing (98.2 - 100%) the cicadas population. Phorate (79.6 - 99.1%) and the mixture triadimenol + disulfoton (82.3 - 97.3%) were also effective, similar to terbufos; aldicarb gave a satisfactory control (68.1 - 85.0%) according to the application method and ethoprophos, did not control well the cicadas when applied with knapsack (58.4%), manually (45.1%) and in furrow (31.5%).
Insecta; Cicadidae; chemical control; coffee; Coffea arabica
