Abbott Laboratories has isolated a new strain of Bacillus thuringiensis aizawai which has shown improved activity against the beet armyworm (Spodoptera exigua) in laboratory and field investigations. Trials were done in cotton in the Brazos Valley of Texas during 1991 VS. armyworm and against Heliothis virescens and Helicoverpa zea in several states during 1991. The product is being developed under the tradename of CenTari and is currently labeled with Experimental Use Permits in the U. S. and with various registrations worldwide.