الفهرس 
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Abstract
The current work was carried out to evaluate the impacts of four
insecticides belonging to different chemical classes; two bioinsecticides
(spinetoram and emamectin benzoate) and two insect growth regulators
(hexaflumuron and teflubenzuron) against the cotton leafworm, S.
littoralis. The tested insecticides were applied by feeding the 4th instar
larvae on castor leaves Ricinus commanis mixed with the tested
insecticides at different concentrations (0.001, 0.01, 0.1, 1 and 10 ppm.).
the study was concerned with the effects on larval development. In
addition, the treated larvae which exhibited any morphological aberration
were recorded. The extended effect on the pupal and adult stages.
Moreover, biochemical effects were adopted. The obtained results can be
summarized as follows:
A- Biological effects:
Larval treatment of S. littoralis with the tested insecticides had a
pronounced effect on the biological activities of this insect.
Larval mortality:
The results demonstrated that emamectin and teflubenzuron were
the most effective and all tested insecticides induced 100% larval
mortality at 10 ppm.
Larval duration:
The tested insecticides induced prolongation in larval duration
which significant with hexaflumuron, in contrast non significant with
other tested insecticides.
Larval growth rate:
The larval growth rates were increased with all tested insecticides at
low concentrations (0.001, 0.01ppm.) which more obvious with
spinetoram, in contrast was decreased at high concentrations which more
obvious with spinetoram and hexaflumuron at 1 ppm.
Percent pupation:
The present pupation was highly decreased compared with control.
This decrease was more pronounced at high concentrations (1and 10
ppm.) than at lower ones.
Pupal duration:
The tested insecticides prolonged the pupal duration. This
prolongation was significant with all tested insecticides except with
teflubenzuron.
Pupal weight:
All the tested insecticides induced a fluctuation in the pupal weight.
This fluctuation was non-significant with hexaflumuron and
teflubenzuron, in contrast was significant with spinetoram and
emamectin.
Adult emergence:
All the tested insecticides induced a reduction in the adult
emergenc. The results demonstrated that all the tested insecticides caused
complete inhibition of the emergency at 10 ppm.
and amylase activity was induced by the tested insecticides, except with
emamectin and teflubenzuron in case of amylase.
Effect on phosphatase enzymes:
Results clarified that the tested insecticides significantly decreased
the activity of acid phosphatase. A highly significant decrease in the
activity of alkaline phosphatase was induced by the tested insecticides.
Effect on non-specific esterase:
It is clearly noticed that teflubenzuron and spinetoram significantly
increased alpha esterases in contrast, decreased with hexaflumuron and
emamectin. A highly significant decreased in beta esterases was induced
by teflubenzuron and hexaflumuron and increased with spinetoram and
emamectin.
Effect on transaminases enzymes:
The obtained results revealed that all tested insecticides induced a
significant inhibitory effect on AST activity and also in ALT activity
except with teflubenzuron.
Effect on acelylcolinesterase, chitinase and phenoloxidase:
Results clarified that acelylcolinesterase significantly increased
with emamectin and teflubenzuron while it was decrease with
hexaflumuron and spinetoram. Phenoloxidase activity was highly
significant increase with all tested insecticides. Chitinase activity was
significant increase with all tested insecticides which pronounced with
emamectin and spinetoram.