Sperm presence and sugar feeding patterns in nulliparous and parous Tabanus quinquevittatus Wiedemann (Diptera: Tabanidae) in southwestern Quebec

The population structure, sperm presence and sugar-feeding pattern of Tabanus quinquevittatus were studied during 2 consecutive years in south-western Quebec. Canopy traps, baited with carbon dioxide or unbaited, were used to collect females. Specimens were dissected for parity, sperm presence, fat-body reserve and stage of terminal follicle development. Diverticulae were tested for the presence of fructose or sucrose by the anthrone test. Parity was similar in both years, nulliparous flies being twice as abundant as parous flies. The prevalence of nulliparous specimens with terminal follicles in stage II suggested that the population studied in south-western Quebec is anautogenous. Sperm was found in 90% (n=1341) and sugar in 88% of specimens dissected; the percentages of sperm and sugar presence were significantly higher in parous than in nulliparous flies. Lower fat-body reserve and earlier stages of terminal follicle development were found in parous than in nulliparous flies.