Insemination rates of hybrids between Culex pipiens pipiens and Culex pipiens quinquefasciatus or Culex pipiens pallens at high temperature

Females of Culex pipiens pallens are rarely inseminated at temperatures above 30 degrees C. Insemination and egg-hatching rates (F2) were examined in females of hybrids (F1) between Culex pipiens pipiens and Culex pipiens quinquefasciatus at 25 degrees C and 30 degrees C to examine temperature-dependent reproductive activity. Insemination rates were very high in hybrid females (F1) at 25 degrees C and 30 degrees C, and egg-hatching rate (F2) also was high at both temperatures. Crosses between Cx. p. pipiens and Cx. p. quinquefasciatus did not show insemination rates and egg-hatching rates similar to the rates observed in Cx. p. pallens, suggesting that the hybrids expressed reproductive activity characteristic of Cx. p. quinquefasciatus.