Bot fly (Cuterebra fontinella fontinella) parasitism of cotton mice (Peromyscus gossypinus) on St. Catherines Island, Georgia

From February 1993 through October 1994, 382 cotton mice (Peromyscus gossypinus) were live-trapped and examined for bot fly (Cuterebra fontinella fontinella) larvae. Thirty-nine (10%) of the mice were parasitized by a total of 44 bot fly larvae. All bots were situated in the inguinal or lower abdominal region of the mice. Monthly data strongly suggested that this bot is bivoltine at this latitude with distinct summer and winter population peaks. Prevalence of parasitism was highest in June 1994 when 56% of 16 mice examined were infested with a mean intensity of 1.3 bots. Adult flies were successfully reared from 10 bots that exited from mice; the time period (58- 98 days, mean = 79.5) that these specimens spent in the soil as pupae further supports the contention that C. f. fontinella is bivoltine on St. Catherines Island.