USE OF P32 IN THE STUDY OF A POPULATION OF SIMULIUM RUGGLESI (DIPTERA: SIMULIIDAE) IN ALGONQUIN PARK, ONTARIO

Abstract

A population of Simulium rugglesi was labelled with P32 by allowing individuals to feed on domestic ducks previously injected with this isotope. Flies that fed on these ducks from June 9–15 were recovered as late as July 12, 28 days after their last possible feeding on labelled ducks. Many rugglesi returned for another blood meal 5–7 days following the previous one; the volume of blood ingested at a meal averaged 1.9(0.50–3.6) mm3. Some individuals were recovered at a site 2 miles from the marking site in a direct line but approximately 6 miles by water, this distance was covered in 5–12 days; marked flies moved with and against the prevailing winds and water currents. The large proportion of labelled to unlabelled flies (503/3747) collected in samples suggested that a small population of rugglesi was involved.