Laboratory studies on blood-feeding of blackflies (Diptera: Simuliidae). 2. Factors affecting fecundity.

The fecundity of autogenous Simulium vittatum and Prosimulium mixtum females was shown to be related to the size of the female which in turn was a result of the quantity of food provided to the larvae. Among females of equal size, sucrose allowed a greater expression of autogeny compared to females given only water. In the case of lab-reared S. Vittatum, a blood-meal enhanced autogenous egg production when females were fed within 24 h after emergence. Preliminary data indicated that for P. mixtum human blood stimulated a greater number of ovarioles to begin maturing compared to avian blood. Evidence was produced which demonstrated a clear decline in fecundity over consecutive gonotrophic cycles for both S. vittatum and P. mixtum.