Abstract Anastrepha fraterculus (Wiedemann, 1830) and Ceratitis capitata (Wiedemann, 1824) are considered the main pests of Brazilian fruit production. Understanding the behavior of species is of great importance for the success of management strategies. This study was to determine the period and search time by attractive food for A. fraterculus and C. capitata adults by using three commercial food attractants: BioAnastrepha™ 5%; Isca Samaritá Tradicional™ 5% and Ceratrap™ 1.5%. The largest catches of A. fraterculus and C. capitata adults in McPhail traps occurred during the day between 6:30 am and 6:30 pm for both species. The BioAnastrepha™ food attractant provided the largest catches compared to Isca Samaritá Tradicional™ and Ceratrap™. In addition, there was a higher prevalence of capturing females than males, for both flies’ species. The period of largest search activity for food attractant was observed from 12h:31 pm to 04:30 pm for A. fraterculus and C. capitata, time of greatest temperature on the day. The definition of the period of largest activity of A. fraterculus and C. capitata adults in the field helps in the elaboration of management strategies to be adopted.

Resumen Se establecieron bioensayos de laboratorio, con el objetivo de evaluar la suscep-tibilidad de adultos del chinche marrón, Euchistus herus, a dos insecticidas orga-nofosforados: Clorpirifos y Acefato. Inicialmente, se determinó la LD50 de los productos y luego se evaluó el porcentaje de mortalidad causado por cada uno de ellos. El efecto de ambos químicos sobre la mortalidad se determinó a las 24, 48, 72 y 96 horas después de la aplicación mediante un diseño experimental con cua-tro (4) tratamientos y cuatro (4) repeticiones. No se detectó diferencias estadísti-camente significativas entre los diferentes tiempos evaluados. El porcentaje de mortalidad con el Acefato fue de 75% en contraste con el Clorpirifos cuyas morta-lidades fueron de 66,6%. Con el fin de alcanzar niveles de mortalidad superiores para lograr un control más efectivo de E. herus, se recomienda realizar ensayos con otros productos que presenten diferentes mecanismos de acción.

Abstract Laboratory test were stablished, with the objective of evaluate the susceptibility of adults of the brown bug, Euchistus herus, to two organophosphorus insecticides: Chlorpyrifos and Acephate. The LC50 of each chemical was initially determined. Later it was evaluated the effect of every product on the mortality of the insect at four different time periods after application. Four experimental treatments (24, 48, 72, 96 hours after the application) were distributed in a random design with 4 replicates each. Within each insecticide there were no significant differences between the mortality and the period of time after application. However, it was observed that Acephate killed 75% of the bugs, while the Chlorpyrifos had a mortality of 66.6%. In order to reach higher levels of mortality and control of E. herus it is recommended to evaluate other chemicals that present different modes of action.