Population dynamic of Euschistus heros in transgenic soybean crops of different development cycles

The neotropical brown stink bug Euschistus heros is one of the major pest of soybean crops; therefore, it is important to carry out periodic samples to assess the population density and help in decision- making control. The objective of this work was to determine the population dynamic of E. heros in transgenic soybean crops of different development cycles. The experiments were carried out in 2013/14 and 2014/15 seasons at FCAV/UNESP, Jaboticabal, SP, Brazil. Three areas of 8.000 m2 (0.8 ha) each one were selected and divided in 80 plots of 100 m2 (10 x 10 m). The transgenic soybean crops were SYN 1365 RR, M 7908 RR and BRS Valiosa RR with early, middle and late cycle, respectively. The samplings were carried out weekly by plant shaking method, and the number of nymphs and adults by sample were recorded. Figures were plotted to determine the population dynamic of mean number of stink bugs by phenological stage of crop, and the influence of meteorological factors were analysed by multiple regression analysis with selection of variable using the “stepwise” method. According to the results of population dynamic, the higher population densities of E. heros are noted in the phenological stage R6, and the maximum temperature is the meteorological factor that has more influence in the variation of E. heros population density.