The presence and distribution of ventral air space gas assures that mosquito pupae are positively buoyant and that they float, dive, and ascend in an upright, balanced orientation. Our objective was to test the effects of mechanical shocks of varying magnitude on mosquito pupae representing 3 genera. Forces that disrupt the pupa's buoyancy and/or hydrostatic balance are of a much lower magnitude than those that would cause tissue damage. Once hydrostatic balance and/or buoyancy are compromised, pupae are unable to restore them and eventually drown. This could represent a weak link in the mosquito life cycle. It is possible that mechanical shock or sound-generating devices could be designed that could break this link.