Laboratory Infection and Release of Spiroplasma (Entomoplasmatales: Spiroplasmataceae) from Horse Flies (Diptera: Tabanidae)

Abstract

Many tabanid flies (Diptera: Tabanidae) are infected with spiroplasmas (Mollicutes: Spiroplasmataceae). Naturally-infected Tabanus gladiator Stone and T. sulcifrons Maquart flies were restrained and fed 10% sucrose to determine the exit points of Spiroplasma from tabanid flies. The flies were allowed to feed for 24 h, and the resulting oral and anal specks were cultured in MID broth. Spiroplasmas were isolated from 21 of 51 oral specks but not from 23 anal specks deposited on plastic. In contrast, when anal specks were deposited in a sucrose solution, 9 of 28 anal specks in sucrose yielded spiroplasma cultures. Tabanus limola F. and T. longiusculus Hine were offered a culture of Spiroplasma strain EC-1 on a stewed raisin or in 5% sucrose in the form of a hanging drop. After 4 d, the minced abdominal viscera of each fly were incubated in MID broth and 25 of 32 tabanids yielded cultures of Spiroplasma.