An intensive study of the grasshoppers of economic importance at Arnaud, Manitoba, 1935

by Herman William Moore

Institution: University of Manitoba
Department: Entomology
Degree: University of Manitoba
Year: 2011
Record ID: 1890697
Full text PDF: http://hdl.handle.net/1993/4705


Arnaud is the first study centre established in Manitoba by the Entomological Branch, Dominion Department of Agriculture, to be dealt with as an "Intensive Study of the Economic Grasshoppers in Typical Environments Where Previous Extensive Outbreaks Have Been Known to Occur." The study of this area is intended to be a long term project, the object of which is "To determine the biological and environmental factors which cause extensive fluctuations in grasshopper populations, with the practical end in view of being able to predict or prevent grasshopper outbreaks." It has long been recognized that grasshoppers must not be forgotten in the years of least abundance of their kind. In the report on the Rocky Mountain Locust in 1877 it was pointed out that "The danger is that during periods of immunity, indifference and forgetfulness intervene until another sweeping disaster takes us by surprise." The danger of this lack of preparation was well known to the late Mr. Norman Criddle who drew the following tenative conclusion from his work in Manitoba (1919-'23 outbreak) and British Columbia (1925), "There is a reason to suspect that the Canmula outbreak might have been prevented had the insects been attacked on their egg beds when they first showed indications of multiplying and it is believed that they may yet be checked by careful attention to the breeding areas in spring and autumn." If for no other reason than the above recognized fact the study of such an area during the next few years of dwindling grasshopper populations would be of great value from the economic standpoint of forecasting the next outbreak. There are, however, other reasons, both practical and scientific, for this intensive study... The data presented in this paper was accumulated while employed by the Entomological Branch, Department of Agriculture, during the summer of 1935 and has been officially released for thesis purposes...