The gonotrophic cycle, survivorship, and daily parity rate of Simulium ochraceum were estimated from specimens collected during routine vector surveillance in southern Mexico, using a vertical (time-specific) method. Series of sequential data analysis on parity of the entomological data obtained in February 1994 showed the highest significant (P < 0.05 alpha) correlation indices (r = 0.63 and r = 0.67) for a 4-day time lag, indicating that the mean gonotrophic cycle length corresponded to 4 days. Daily survival rate was estimated to be 0.80, the survival to infective age (12 days) to be 6.9%, and the daily parity rate to be 0.41. These estimations are in accordance with those previously obtained by others from mark-release-recapture experiments (horizontal method) in Guatemala.