EFFECTS OF BACILLUS-THURINGIENSIS TOXINS IN TRANSGENIC COTTON AND POTATO ON FOLSOMIA-CANDIDA (COLLEMBOLA, ISOTOMIDAE) AND OPPIA NITENS (ACARI, ORBATIDAE)

Methods are reported for testing the effects of toxins or small molecu les [Bacillus thuringiensis ssp. kurstaki delta-endotoxins HD-1 CryIA( b) and HD-73 CryIA(c)] in plants (cotton and potato) on 2 nontarget so il arthropods, a collembolan, Folsomia candida Willem, and an orbatid mite, Oppia nitens Koch. Time to oviposition, egg production, and Fina l body length were unaffected when F. candida were fed residues of tra nsgenic cotton lines #81 or #249. Total production of O. nitens adults and nymphs was unaffected Ly feeding on leaves of both transgenic cot ton lines. with B. thuringiensis ssp. tenebrionis CryIIIA in potato, n o differences were seen in the 3 indices for F. candida. Overall, tran sgenic toxin sources had no negative effects, but similar tests with c admium as a positive control showed a concentration-rate response of d ecreased reproduction.