The termination of prolonged quiescence (diapause) in the house dust mite, Dermatophagoides farinae at room temperature

Abstract

To elucidate the ecological role of prolonged quiescence (diapause) in proto- and/or pharate tritonymphs of the house dust mite, Dermatophagoides farinae, five groups of nymphs which became quiescent at different periods in May, June, July 1988 and September 1989,were placed in a house room from November of the each year until June 1990. They were incubated over saturated sodium choride solution in a tightly fitted plastic box. Most of the nymphs in each group overwintered and terminated quiescence almost synchronously during the period from April to June (mainly, May) of the following year, irrespective of the time when they entered into quiescence. A few nymphs continued quiescence for over 1 year, and most of them overwintered again and also moulted in April. These results suggest that the prolonged quiescent nymphs have a key role in regulating the population dynamics of the mites with their ability to overwinter and to provide breeding stocks for the population growth in spring through summer.