The development of resistance to hydrocyanic acid in certain scale insects

Abstract

Abstract does not appear. First page follows. Introduction and Review of Literature In 1914 Melander published an article under the title, “Can Insects Become Resistant to Sprays?” Two years later an article appeared under the title, “Are Scale Insects Becoming Resistant to Hydrocyanic Acid Fumigation?” (Quayle, 1916). Since the possibility that insects could develop a tolerance for sprays and fumigants was a new conception, the writers quoted put the titles to their first articles in the form of questions. With the accumulation of more evidence, the present writer became more confident, and six years later published an article entitled, “Resistance of Certain Scale Insects in Certain Localities to Hydrocyanic Fumigation” (Quayle, 1922); Melander, nine years after his first article appeared, published a second article entitled, “Tolerance of San Jose Scale to Sprays” (Melander, 1923). Since that time other writers (Woglum, 1925); (Gray and Kirkpatrick, 1929, a), (b) have secured additional evidence on resistance in relation to fumigation; and members of the Citrus Experiment Station staff and other workers whose investigations are related to the question have secured ample evidence to support what the writer now considers a well-established fact. There are still, however, dissenting opinions. (Moore (1933), p. 1161) states, “Under favorable conditions, there is no significant difference between the kills of ‘resistant’ and ‘nonresistant’ red scale.