Further studies on the effect of aging and mating history of males on cytoplasmic incompatibility inCulex pipiens fatigans

Previously reported effects of aging and mating history in causing partial loss of cytoplasmic incompatibility in males of Paris cytoplasmic type, have been shown also to occur in males with Delhi and Hamburg cytoplasmic types. It was unexpectedly found that increasing the ratio of females to males at the first mating did not lead to enhancement of the level of partial compatibility when the males were re-mated. The effect of aging is discussed in relation to the use of cytoplasmic incompatibility integrated with chromosomal abnormalities, for genetic control.