Use of Bacillus thuringiensis for Tobacco Budworm Control: Effects at Low Dose Rates

Kumudinie M. Karunaratne and Frederick W. Plapp, Jr.


 
ABSTRACT

A laboratory assay was developed to determine the effects of low doses of Bacillus thuringiensis var kurstaki on larvae of the tobacco budworm (TBW), Heliothis virescens (F.). Larvae were exposed to B.t. in artificial diet for 3-5 days and the effects of B.t. treatment on survival, growth, and development were measured. Surviving larvae were then exposed to discriminating doses of profenofos, thiodicarb, or cypermethrin. Exposure to B.t. greatly slowed the development of the larvae at concentrations as low as 2 parts per trillion, but did not produce mortality. The treatments did not change responses to insecticides relative to untreated controls. The data suggest that exposure to low rates of B.t. alone may be useful in managing TBW and that the major effect of B.t. may be as an insect growth regulator.



Reprinted from 1993 Proceedings Beltwide Cotton Conferences pp. 835 - 837
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998