Effects of Ascogregarina barretti (Eugregarinida: Lecudinidae) infection on Aedes triseriatus (Diptera: Culicidae) in Illinois.

Ascogregarina barretti (Vavra), a gregarine protozoan parasite, infected 23.6 and 5.0% of Aedes triseriatus (Say) adults that emerged from pupae collected from an east-central Illinois tire dump in 1990 and 1991, respectively. Infection significantly reduced the wing length of males and females in both years, but its effect was greatest in 1991. Females were approximately 1.7 times as likely to be infected as males. Infected pupae were 3.53 and 2.76 times more likely to die than uninfected pupae in 1990 and 1991, respectively. Wing length also was affected by location within the tire dump and by tire water volume. We conclude that the A. barretti infection was deleterious to Ae. triseriatus and that the effects of this pathogen may be moderated by environmental factors.