The efficacy of range of compounds: three botanical insecticides
(NeemAzal T/S, Trifolio S-forte and an extract of Quassia
amara L.) and two pyrethroid insecticides, lambda-cyhalothrin
(Karate 9.4% S.C) and deltamethrin (Decis 2.8% E.C.)
were evaluated to control Rhopalosiphum padi (L.) and Metopolophium
dirhodum (Wlk.). Different concentrations were
used to study efficiency of the tested compounds on both
aphid species 24, 48 and 72 hours post treatment in the laboratory.
Bio-residual activity of these compounds was evaluated
on wheat plants in the greenhouse. M. dirhodum was more
susceptible than R. padi in all treatments. The mortality
reached 100% after 24 h in M. dirhodum and after 48 h in
R. padi. Most of the tested compounds caused acceptable levels
of cereal aphid’s control. A sharp decrease in persistence of
the bioactivity of tested compounds against the 4th instar of
R. padi and M. dirhodum was noticed after 7 days from application.
Bio-residual activity declined with days, started with
more than 80% on zero time and reached 12% after 7 days in
Decis, while it was 70% on zero time and reached 10% after
7 days in Karate. Decis, Karate and NeemAzal T/S are considered
the most effective in controlling cereal aphids.