Some plants of the Myrtaceae family have active principles that inhibit the development and growth of many insects, according to experts, with antifeedant effect, repellent and insecticide. In the present study, we evaluated the bioactivity of three doses of compound extract from seeds of Myrciaria dubia (Kunth) McVaugh, Myrtaceae, bioprocessed in order to use them for the biocontrol of Callosobruchus maculatus in the grass legume Vigna unguiculata (L.) Walp (cowpea) without previous treatment. The sequential probability ratio test for the period and minimum dose of extract application was applied with and without the presence of M. dubia, inter-related to the health and physiological behavior of cowpea, evaluated initially at six and fifty days of infestation. The positive effect was obtained around 94% for the health and in the physiological evaluation, an average value of 73% of effectiveness on the doses tested, which showed no significant difference with each other. The extract caused the death of adult C. maculatus and the immobilization of hatchings in cowpea. In the In vitro conditions, it has insecticidal and controlling bioactive properties with potential for use in preservation of stored seeds and grain of grass legumes such as Vigna unguiculata (L.) Walp.