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EFFECTS OF MOISTURE, GRAVITY, AND LIGHT ON THE BEHAVIOR OF LARVAE OF THE WHEAT STEM SAWFLY, CEPHUS CINCTUS (HYMENOPTERA: CEPHIDAE)

Published online by Cambridge University Press:  31 May 2012

N. D. Holmes
N. D. Holmes
Affiliation:
Research Station, Canada Department of Agriculture, Lethbridge, Alberta
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Abstract

Until mid- or late July, most larvae of the wheat stem sawfly generally move into the upper internodes of the host stems. Then, as the stems mature, the larvae migrate down to the basal internodes and cut the stems at about ground level.

The migration is initiated in response to the visible and infrared light transmitted through the ripening stems. The direction of the migration, toward the basal internodes, results from the orientation of the larvae to the vertical axis of the stems reinforced by a positive larval response to gravity.

The larvae cut the stems at ground level because they are shielded there by the soil from visible and infrared radiation. The location of cutting is also influenced by the preference of the larvae for drier sites in which to cut.

The date of cutting is directly related to the loss of moisture from the stems, but not to a precise level of stem moisture. The larvae may form their cocoons in response to desiccation.

Type
Articles
Information
The Canadian Entomologist , Volume 107 , Issue 4 , April 1975 , pp. 391 - 401
Copyright
Copyright © Entomological Society of Canada 1975

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References

Ainslie, C. N. 1928. The western grass-stem sawfly a pest of small grains. Tech. Bull. U.S. Dep. Agric., No. 157.Google Scholar
Holmes, N. D. 1954. Food relations of the wheat stem sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae). Can. Ent. 86: 159–167.CrossRefGoogle Scholar
Holmes, N. D. and Farstad, C. W.. 1956. Effects of field exposure on immature stages of the wheat stem sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae). Can. J. agric. Sci. 36: 196–202.Google Scholar
Holmes, N. D., Nelson, W. A., Peterson, L. K., and Farstad, C. W.. 1963. Causes of variations in effectiveness of Bracon cephi (Gahan) (Hymenoptera: Braconidae) as a parasite of the wheat stem sawfly. Can. Ent. 95: 113–126.CrossRefGoogle Scholar
Holmes, N. D. and Peterson, L. K.. 1960. The influence of the host on oviposition by the wheat stem sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae). Can. J. Pl. Sci. 40: 29–46.CrossRefGoogle Scholar
Kasting, R. and McGinnis, A. J.. 1958. Note on a method of artificially sustaining larvae of the wheat stem sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae). Can. Ent. 90: 63–64.CrossRefGoogle Scholar
Villacorta, A., Bell, R. A., and Callenbach, J. A.. 1971. Influence of high temperature and light on postdiapause development of the wheat stem sawfly. J. econ. Ent. 64: 749–751.CrossRefGoogle Scholar