Morphological and Physiological Distinction between Two Populations of the Peach–Potato Aphid

Abstract

INDIVIDUAL Myzus persicae (Sulz.) which had survived repeated spraying with organophosphorus insecticides were collected from plants grown in glasshouses in 1963 and 1964 and were allowed to multiply on Brassica pekinensis Rupr. Several populations, derived from aphids collected in different glasshouses and from different species of host plant, were reared on B. pekinensis in separate insect proof cages for more than 2 yr. Experiments showed that these populations were much more resistant to organophosphates than another designated NC (normal colony), which had not been exposed to these insecticides¹. During 1965 and 1966 experiments were carried out to investigate whether aphids from one of these populations resistant to insecticides (RR3) differed from NC aphids in morphology as well as in physiology.