The Influence of Spray Programs on the Fauna of Apple Orchards in Nova Scotia. V. The Predacious Thrips Haplothrips faurei Hood

Abstract

Lord (1949) listed the predators of the European red mite, Metatetranychus ulmi (Koch.), in Nova Scotia and described the effects of a number of chemicals on them. Among the more important predators is the thrips Haplothrips faurei Hood. This thrips, however, does not confine its feeding to European red mite eggs but readily attacks the eggs of many other mites and insects. There is strong evidence that it is one of the most important biotic factors in the natural control of insect and mite pests in Nova Scotia apple orchards. It and another species, Leptothrips mali (Fitch), are the only thrips of economic significance, and H. faurei, because of its greater numbers, is the more important. A description of the life-history of L. mali was given by Bailey (1940), who also (1939) studied the biology of another thrips, Scolothrips sexmaculatus (Perg.), which is of minor importance in Nova Scotia. The only other predacious thrips found is a species bclieved to be Zygothrips minutus Uzel, which occurs only rarely and in small numbers. Haplothrips subtilissimus Hal. (later identified as H. faurei), was found by Putman (1942) in Ontario to be predacious on phytophagons mites and the eggs of oriental fruit moth, Grapholitha molesta Busck.