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BIOASSAY SYSTEMS FOR THE PYRETHRINS: V. EXPERIMENTS WITH A RESISTANT STRAIN OF CALANDRA GRANARIA L.
Author(s) -
BLACKITH R. E.
Publication year - 1953
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1953.tb02370.x
Subject(s) - pyrethrum , biology , mahalanobis distance , bioassay , strain (injury) , regression , resistance (ecology) , statistics , selection (genetic algorithm) , toxicology , mathematics , ecology , pesticide , artificial intelligence , computer science , anatomy
Some principles of testing for resistance in wild and laboratory stocks of insects are discussed, and experiments with Calandra granaria L. are described in which these insects are selected for pyrethrum resistance. A new method is described of expressing relative tolerances when the relevant regression lines are not parallel, based on the ‘generalized distance’ of Mahalanobis. The method may equally be used for the comparison of two insecticides giving rise to lines of different slope. A limited increase in resistance occurred on selection. Non‐random oscillatory sequences of slopes were observed when the resistant strain was assayed, and regression parameters computed. The nature of these oscillations is considered.