The aim of this study was to assess the efficacy of tau - fluvalinate and lambda - cyhalothrin based insecticides in the control of P. rapae and P. xylostella caterpillars. In the agro-ecological conditions of Vojvodina province (Serbia) (localities Futog and Čurug) the production of cabbage is present every year at vast areas. During 2011, the experiments were performed according to a standard EPPO (PP PP 1/83 (2) 2004) method. The applied preparations are based on tau - fluvalinate (240 g of a.s. /l of the preparation) Mavrik - EW in amount of 0.3 l/ ha, and lambda - cyhalothrin (25 g/l of the preparation) Grom, in the amount 0.4 l/ha. The assessment of pests population abundance was performed before the treatment, two i.e. four and seven days after the treatment. The efficacy of insecticides was determined according to Henderson and Tilton and significance of differences by ANOVA.The average number of P. rapae caterpillars (25 plants/repetition) in Futog site before the treatment was 4.7 - 6.2, after four days it was 0-0.2 and after seven days 0.25-1.25, regardless on the applied insecticides, while the number in the control was 7.7 after four and 10.2 after seven days. Efficacy of insecticides at this site after four days ranged from 96.4 to 100 % and after seven days 89.8 - 97.3 %. At Čurug locality, the number of P. rapae caterpillars before the treatment was 9.7 - 12, while after two and seven days it ranged from 0.5 to 0.75, whereas in the control it was 11.5 after two and 11 after seven days. At this site, two days after the treatment, the efficacy ranged from 93.8 to 95.3 %, and after seven days from 92.7 to 96 %. The average number of P. xylostella caterpillars at locality Futog before the treatment was 13.5 -17.7. Four days after the treatment it was 1.75 - 2.25, and after seven days 1-1.25, while in the control it was 23.0 after four and 27.2 after seven days. At site Čurug before the treatment the average number of P. xylostella caterpillars ranged from 14 to 16.7. Two days after the treatment the average number ranged from 0.75 to 1, and after seven days 0-0.5, regardless on the applied insecticides, while in the control it was 13.0 after two days and 10 after seven days. The efficacy of tested insecticides for controlling P. xylostella caterpillars at Futog site ranged from 87.3 to 92.1 %, after four, and 94.1- 96.2 % after seven days. At Čurug, the efficacy ranged from 92.7 to 95.2 %, after two days and 95.3 to 100 % after seven days. By choosing insecticides based on tau-fluvalinate and lambda-cyhalothrin, in addition to satisfactory efficacy in the control of harmful caterpillars of cabbage, the applied amounts of a pyrethroids, compared to organophosphorus insecticides are far smaller i.e. 79 g and 10 g a.s./ha (respectively).

Pieris rapae, Plutella xylostella, cabbage, insecticide, efficacy

Presentation: oral