Efficacy of some biological insecticides in the control of potato bettle Colorado (Coleoptera – Leptinotarsa decemlineata Say)

Abstract

In Europe is developing more and more a market that demands organic farming potatoes where the pest control against the Colorado beetle is done with bio pesticides. In order to accomplish organic farming yields for potatoes, at the Agricultural Research and Development Station from Suceava, biological insecticides Laser 240 SC (spinosad- metabolite extracted from the actinomicet Saccharopolyspora spinosa) and NeemAzal T/S (azadirachtin – plant secondary metabolite from the Azadirachta indica A. Juss. tree) were tested. In lab conditions, NemmAzal-T/S had high efficacy against young larvae and lower to adults. In field conditions, the doses of 2 and 2.5 l/ha in 500 l water, applied to the first age of larvae, reduced the density / plants. It is necessary a bigger quantity of water for the sprinkling in order to cover thee of leafs because spinosad works semi-systemic. Laser 240 SC, after some days, was very efficient against all larvae, young or old. Given to the homologate dose of 0.1 litres/ha the testes were fulfilled with a smaller quantity (0.08l /ha) with the same efficacy.