Seasonal changes in Larval populations of Culicoides subimmaculatus Lee & Reye (Diptera: Ceratopogonidae), with observations on the influence of tides on larval ecology

Abstract

At Tingalpa Creek, Brisbane, larvae and pupae of Culicoides subimmaculatus were most numerous 1.94 m above datum, midway between mean high-water neaps and mean high-water springs. Monitoring of a field population of immature stages indicated that C. subimmaculatus completes four generations a year, and overwinters in the 4th larval instar. Adults emerge during synchronized periods associated with the lunar tidal cycle; however laboratory experiments indicated that tidal coverage did not affect the time of adult eclosion or of pupation. It is suggested that synchronization occurs at an earlier point in the life cycle, possibly at ecdysis of 3rd to 4th instars.