Experiments were carried out at Zagazig district, Sharqia
Governorate during two successive seasons, 2007 & 2008 to
evaluate the toxicity of some insecticides against 5. llttora/is larvae
infesting cotton cultivations and some associated common
predators.
Chlorpyrifos and methoxyfenozide were the most potent
insecticide in both initial and residual effect that caused highly
significant reduction in the infestation rates of the pest as
compared to other treatments at the initial and residual effects that
recorded (98.21±0.783, 82.55±2.444%) as initial effect and
(93.34±2.599, 85.32±2.195%) as residual effect during 2007 while
during 2008 season t recorded (96.01±0.723, 83.97±3.462%)
and (89.89±2.715, 86.34±3.398 %) for initial and residual effect,
respectively. Considering the initial and residual effects of the rest
treatments, it could be arranged descendingly as teflubenzuron,
tebufenozide, Tracer and finally Dipel 2X at both tested seasons.
Chiorpyrifos and methoxyfenozide were the most toxic
insecticides causing the highest significant reduction in the predator
numbers that recorded (79.81±3.544, 24.73±2.162%) and
(66.81±5.418, 29.36±3.468%) at 2007 and (71.60±3.84,
23.50±1.799%) and (64.91±3.569, 26.78±3.548) at 2008 in the
initial and residual effects, respectively. Followed by Tracer,
teflubenzuron, tebufenozide and Dipel 2X during the two successive
seasons