The ecology of Honey Creek, Oklahoma: population dynamics and drifting behavior of three species of Simulium (Diptera: Simuliidae)

Abstract

The population dynamics and drifting behavior of S. virgatum, S. trivittatum, and Simulium sp. A were investigated at 9 stations in a south-central Oklahoma [USA] limestone stream from June 1972-Aug. 1973. Simulium sp. A abundance paralleled vernal periphyton increases and exhibited characteristic midsummer and midwinter decreases, while S. virgatum and S. trivittatum were most prevalent during late summer and early fall. Simulium sp. A and S. virgatum oviposited during the evening crepuscular period. In Simulium sp. A synchronous egg maturation and eclosion apparently imparted a degree of drift rhythmicity in the early instars which progressively degenerated during larval development. S. virgatum drift rates were highest during midafternoon and were correlated with diel changes in water temperature. S. trivittatum drift rates were highest during the evening and morning and lowest during the afternoon.