The inbreeding in natural populations results in a loss in the genetic variability that can influence juvenile and adult mortality, the size, viability and fertility of the offspring, as well as the individuals morphology. Apanteles piceotrichosus (Blanchard, 1943) (Hymenoptera, Braconidae) is a Plutella xylostella Linnaeus,1758 parasitoid (Lepidoptera, Yponomeutidae) that has been attracting a lot of attention to a biocontrol purpose, because it can be used as agent of biological control. For the creation and liberation of parasitoids are necessary studies on its biology. The objective of the present study was carried out to examine the inbreeding effect on the mortality, longevity and sexual ratio of A piceotrichosus. The parasitoid attack rate was also observed. The crossings, scheduled, were made starting from individuals collected in field and breed in laboratory under controlled conditions. Were not observed significant differences in mortality and longevity of A piceotrichosus, as well as in the rate of attack of the parasitoid on the host. The sexual ratio showed significant differences among the control and inbreeding group. Even so differences were not observed inside of the inbreeding group. none