Research Reports: Population Suppression of Mahogany Webworm, Macalla Thyrsisalis (Lepidoptera: Pyralidae), with Natural Products

Authors

  • F. W. Howard

Abstract

In laboratory tests, both Margosan-O, diluted to 20 ppm azadirachtin in water, and Dipel 2X, which contains the entomopathogenic bacterium, Bacillus thuringiensis var. kurstaki Berliner, at 9,600,000 international units (i.u.)/liter H@^2O, applied to foliage of West Indies mahogany, Swietenia mahagoni Jacquin, inhibited feeding by young mahogany webworms, Macalla thyrsisalis Walker, as measured by differences in growth and in the production of fecal pellets (P < 0.05). No clear effect was observed on older larvae. In a field test, the mean number of larvae per tree was reduced 10-fold (P < 0.05) ten days after treatments with either 20 ppm azadirachtin in H@^2O or B. t at 19,200,000 i.u./liter H@^2O applied to the foliage of West Indies mahogony. One or more treatments with either of these materials during the spring when mahogony webworms are active on foliage is a suitable method of controlling this pest.

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Published

1990-06-01

Issue

Section

Literature Review Articles