Gender-specific bacterial composition of black flies (Diptera: Simuliidae)

black fly; culture-independent analysis; gender; phylogeny. Although hematophagous black flies are well-known socioeconomic pests and vectors of disease agents, their associated bacteria are poorly known. A system-atic analysis of the bacterial community associated with freshly emerged adult black flies of four North American species, using cultivation-independent molecular techniques, revealed 75 nonsingleton bacterial phylotypes. Although 17 cosmopolitan phylotypes were shared among host species, each fly species had a distinct bacterial profile. The bacterial composition, however, did not correlate strongly with the host phylogeny but differed between male and female flies of the same species from the same habitat, demonstrating that a group of insects have a gender-dependent bacterial community. In general, female flies harbor a less diverse bacterial community than do males. The ana-tomical locations of selected bacteria were revealed using fluorescence in situ hybridization. Understanding the physiological function of the associated bac-terial community could provide clues for developing novel pest-management strategies