Persistence of Bacillus thuringiensis subsp. kurstaki after an aerial application

Abstract: On May 7th 2007 a commercial preparation of Bacillus thuringiensis subsp. kurstakistrain HD1 (Btk-HD1) was applied by aircraft in an oak forest near Florence (Italy) to controlOak processionary moth (Thaumetopoea processionea L.). The persistence of Btk-HD1 in the oakforest was assessed by collecting leaf, litter and soil samples 24h before and 24h after thetreatment. Further soil samples were collected 36, 84 and 122 days after the Btk-HD1 application.The presence of Btk-HD1 was detected by morphotyping analysis followed by a high throughputstaining methodology and PCR analysis. Btk-HD1 was isolated both from leaves and littercollected 24h after treatment, but never from soil of the oak forest.