Partial loss of cytoplasmic incompatibility with age in males of Culex fatigans.

The cytoplasms of Paris and Delhi strains of Culex fatigans have been reported to be bi-directionally incompatible. However, in the present study it is shown that with increasing age males with Paris cytoplasm show an increasing degree of partial compatibility with Delhi females. A male history of previous mating seems a contributory effect in enhancing the degree of partial compatibility. The relevance of partial compatibility to genetic control of C. fatigans is discussed.