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Abundance and Relative Importance of Caterpillars Attacking Cabbage in Eastern Ontario1

Published online by Cambridge University Press:  31 May 2012

D. G. Harcourt
Affiliation:
Vegetable Insect Section, Entomology Laboratory, Ottawa, Canada
R. H. Backs
Affiliation:
Vegetable Insect Section, Entomology Laboratory, Ottawa, Canada
L. M. Cass
Affiliation:
Vegetable Insect Section, Entomology Laboratory, Ottawa, Canada

Extract

Cabbage and related crops are attacked every year throughout Ontario by caterpillars of three species, namely, the imported cabbageworm, Pieris rapae (L.), the diamondback moth, Plutella maculipennis (Curt.), and the cabbage looper, Trichoplusia ni (Hbn.). The imported cabbageworm is generally regarded as the most abundant of the three species and is reported as doing damage of considerable economic importance each year. The cabbage looper does not occur in large numbers until late in the season, but in most years it is believed to be second only in importance to the imported cabbageworm. The diamondback moth is generally considered to be much less important than the other two species (Caesar, 19i8). As previously reported (Matthewman et al., 1952), these beliefs were not borne our by observations of field populations at Ottawa in 1950. Whereas populations of the cabbage looper were strikingly low, those of the diamondback moth were much higher than the literature indicated. This paper is a summary of four seasons' experiments, 1951-1954, undertaken to assess the abundance and relative importance of the three species in eastern Ontario.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1955

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References

Caesar, L. 1938. Insects attacking vegetables. Ontario Dept. Agr. Bull. 393.Google Scholar
Harcourt, D. G. 1954. The biology and ecology of the diamondback moth, Plutella maculipennis Curt., in eastern Ontario. Ph.D. thesis. Cornell University.Google Scholar
Harrison, P. K., and Brubaker, R. W.. 1943. The relative abundance of cabbage caterpillars on cole, crops grown under similar conditions. J. Econ. Ent. 36: 589592.CrossRefGoogle Scholar
Matthewman, W. G., Harcourt, D. G., and Perron, J. P.. 1952. Timing of DDT applications for control of caterpillars on cabbage. Canadian Ent. 84: 346352.CrossRefGoogle Scholar
Reid, W. J., and Bare, C. O.. 1952. Seasonal populations of cabbage caterpillars in the Charleston, S.C., area. J. Econ. Ent. 45: 695699.CrossRefGoogle Scholar
Twinn, C. R. 1924. Studies in the life history, bionomics and control of the imported cabbageworm in Ontario. 54th Ann. Rept. Ent. Soc. Ontario, 1923, pp. 8286.Google Scholar
Wilson, H. F., Pickett, R. C., and Gentner, L. G.. 1919. The common cabbageworm in Wisconsin (Pontia rapae Linn.). Wisconsin Agr. Expt. Sta. Res. Bull. 45.Google Scholar