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Aerial survey reveals detailed spruce budworm damage in forest areas, highlighting difficulties in assessment.
It has never been easy for entomologists to determine the extent and seriousness of forest insect damage. Roadless, inaccessible areas have always been extremely difficult to survey, and it has not always been possible to sample all infested areas satisfactorily from the ground. The advent of the airplane and its development, however, have made it possible to observe all forested areas, no matter how remote, and to determine insect conditions more accurately then had been done in the past.
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Heller et al. (1952) studied this question.
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