Efficacy and speed of action of selected plant protection products on Lymantria dispar in laboratory conditions

Abstract

In this study some selected insecticides were evaluated for their effect on gypsy moth Lymantria dispar L., (Lepidoptera: Lymantriidae) under laboratory conditions. Diflubenzuron, methoxyfenozide, triflumuron, fenoxycarb, fenoxycarb + lufenuron, Bacillus thuringiensis 50% subsp. kurstaki + Bacillus thuringiensis 50% subsp. aizawai, Bacillus thuringiensis subsp. aizawai and spinosad were used in the recommended concentration, against the 1 st , 2 nd , 3 rd and 4 th larval instars of L. dispar. The effectiveness of the above insecticides as well as the speed of action (LTime 50 and LTime 90 ) expressed in days, were examined in detail. Spinosad and methoxyfenozide presents a relatively higher speed of action in relation to the other insecticides. LTime 50 of spinosad and methoxyfenozide did not differ significantly among the first three larval instars and ranged from 0 to 0.61 and 1.13 to 1.74 days, respectively. Regarding IGRs, the mixture (fenoxycarb + lufenuron) and triflumuron were the most effective in relation to the other IGRs tested. Moreover, Bacillus thuringiensis toxins were effective only against the first two larval instars.

Evaluation of Chitin Synthesis Inhibitor, lufenuron 5.4 EC against Maruca vitrata (Geyer) in Blackgram

“…It is essential to kill the first instar larvae at the period when they hatch to till they enter the flowers and buds as documented by Yadav and Dahiya, (2004), Subharani and Singh (2010). Fenoxycarb + lufenuron acted faster against the first two larval instars of Lymantria dispar (LT 50 values were 0.99 and 1.81 days, respectively) as reported by Zartaloudis et. al.…”