Use of corn plants as traps to prevent colonization of soybean by phytophagous pentatomids in Argentina

Corn plants were tested as trap crop to mitigate the invasion of soybean areas by phytophagous pentatomids in Paraná, Entre Ríos, Argentina (31º 51' 9.6" S, 60º 32' 11.2" O). Eight plots (30 x 30 m) of transgenic soybean LAE 9972402, maturation group 5.5 were used. Four plots were surrounded by five rows of corn cv. NK940 plants, used as trap or “life barrier”, and four plots were not. Samples of stink bugs were taken at random using the beat cloth (five beats/plot) on all eight plots to detect the presence of bugs from the period of pre-blooming to soybean plant maturation. At harvest, seed yield was measured, and seed samples examined to determine weight of 100 seeds. Piezodorus guildinii (Westwood) (51%) and Nezara viridula (L.) (43%) were the main pentatomids intercepted; bugs were present in smaller numbers in the soybean plots surrounded by corn compared to soybean plots alone. At maturation (R8), population peaked with 1.4 bugs/m in the plots with the trap plants, and 1.9 bugs/m in the check plots. Seed yield and weight of 100 seeds were significantly (LSD Fisher P=0.05) greater for the plots containing the trap crop as compared to those without the corn plants.