Insect Behaviour Research Laboratory, Department of Zoology, University of Delhi, Delhi - 110 007, (India).
Feeding responses of the spotted stem borer, Chilo partellus (Swinhoe) larvae to the foliage extracts of two cultivars viz., Basi local and Kisan, were studied in the laboratory. The foliage of these two maize cultivars was extracted in aqueous methanol and n-hexane for their polar and non-polar constituents, respectively. The crude extracts were concentrated and applied on cellulose acetate discs before being fed to the larvae. Significant differences were observed in the feeding responses of the stem borer larvae to the crude solvent extracts of the two cultivars. The larvae consumed significantly greater quantity of the cellulose acetate discs treated with n-hexane and methanol extracts of Basi local leaves than the discs treated with corresponding extracts of Kisan leaves. This indicated the role of polar as well as non-polar chemicals in governing the feeding responses of the larvae. Evidently, the Kisan foliage contains certain chemical factors, which adversely affected the feeding responses of the stem borer larvae.
