单宁对苏云金芽孢杆菌库斯塔克变种杀棉铃虫效力的作用(英文)

本文报道棉铃虫、苏云金芽孢杆菌库斯塔克变种和单宁三者间的相互作用。苏云金芽孢杆菌芽孢晶体混合粉以6个不同的浓度（0％，0．005％，0．01％，0．015％，0．02％，0．025％湿重）分别加入含0．025％单宁和不含单宁的人工饲料中。初孵幼虫分别在上述饲料中饲养48h后，转入相应的不含苏云金芽孢杆菌的人工饲料上饲养，直到留存的幼虫化蛹。结果表明，单宁与苏云金芽孢杆菌混用可提高苏云金芽孢杆菌对棉铃虫的毒力，LD50降低45％，并可显著抑制该虫的生长发育，但二者在抑制生长发育方面无交互作用。选择取食试验显示，苏云金芽孢杆菌对五龄幼虫有显著的抑食性，但单宁无此作用，单宁与苏云金芽孢杆菌混用不会增强抑食性，但单宁能抑制苏云金芽孢杆菌菌落的生长，浓度高于15mg／100ml还能抑制芽孢的萌发。

EFFECT OF TANNIC ACID ON THE EFFECTIVENESS OF BACILLUS THURINGIENSIS VAR. KURSTAKI AGAINST HELICOVERPA ARMIGERA (HUBNER)

The role of tannic acid in increasing effectiveness of Bacillus thuringiensis var. kurstaki(HD-1) against Helicoverpa armigera was examined in bioassays on semisynthetic diet. Concentrationsof B. thuringiensis (0 %, 0. 005 % , 0. 01 %, 0. 015 %, 0. 02 % , 0. 025 % wet weight) were incorpo-rated into the diet containing 0. 025% tannic acid and tannic acid-free diet. LD50 of B. thuringiensiswith tannic acid were 0. 006% but that without tannic acid was 0. 011 %. Both B. thuringiensis and tan-nic acid retarded growth of H. armigera significantly, but there was no synergetic effect between them.Choice tests showed that B. thuringiensis deterred feeding of the fifth instar larvae of H. armigera buttannic acid had no such effect. Experiments on colony growth of B. thuringiensis on NBA media con-taining tannic acid (0, 1, 3, 6, 9, 12, 15, 18, 21 mg/100 ml) dernonstrated that tannic acid reducedcolony growth of B. thuringiensis, and inhibited sporulation above 15 mg/100 ml.