Rhipicephalus microplus represents an important challenge for cattle farming due to economic losses and growing resistance to chemical acaricides. In this context, this study evaluated the temporal dynamics of survival of engorged females of R. microplus exposed to different concentrations of a commercial formulation of Steinernema carpocapsae. Three independent bioassays were conducted, in which survival was analyzed by Kaplan–Meier curves, Cox proportional hazards model and TL50 and TL90 estimates. The infectivity of nematodes recovered from engorged females was subsequently evaluated in Tenebrio molitor. The more concentrated suspensions promoted a faster reduction in survival, shorter lethal times and higher risk ratios, while the 130 mL dilution showed a later response. Despite the variation in lethal times between bioassays, a consistent pattern of response was observed between the concentrations evaluated. The recovered nematodes remained infectious, causing mortality in T. molitor. The results demonstrate that the analysis of the temporal dynamics of mortality provides a more comprehensive characterization of the activity of S. carpocapsae on R. microplus, expanding the understanding of its application as a biological control agent.