Studies on the Relations of Insect and Host Plant: II. Effects of Water Stress in Host Plants on the Fecundity of Myzus persicae (Sulz.) and Brevicoryne brassicae (L.)

Abstract

IN a further investigation of the problem of the effects of water stress in host plants in pots on the reproduction of aphids, individuals of Myzus persicae and Brevicoryne brassicae have been studied on young, mature and old leaves of brussels sprouts (var. ‘Jade Cross’) which were growing in three water regimes¹. All experiments were conducted at 20° C in a daylength of 16 h. Fourth instar nymphs in leaf cages (twelve replicates) moulted to adult and larviposited, and one of the offspring was reared to adult in each cage. Throughout the reproductive life of these adults, their progeny were removed daily and counted to measure fecundity (Fig. 1).