Bacillus thuringiensis spp. kurstaki as an effective control agent of lepidopteran pests in tomato fields in Israel.
Chrysodeixis chalcites, which is a major pest of tomato in Israel, was controlled in a series of field applications (5000 g of 8000 IU/mg, in 150-200 litres/ha) with strains of Bacillus thuringiensis subsp. kurstaki. All instars were susceptible to B. thuringiensis. Thus, timing of application was not crucial for effective larval control of C. chalcites. Heliothis armigera [Helicoverpa armigera] usually accompanied the major pest at low to medium population densities (2-4 larvae per metre row). In 38 of 40 commercial fields (2-35 ha each), applications of B. thuringiensis suppressed pest populations to levels below the economic threshold and were comparable with effective chemical pesticides. In tomato fields adjacent to potato fields, extensive damage is caused by the gelechiid Phthorimaea operculella. Three consecutive applications of B. thuringiensis at a high volume (500 litres/ha) were required to control this species.