الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
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SUMMARY
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SUMMARY
Electrophysiological studies were conducted in the
laboratory of biophysics in the Faculty of Science, Ain Shams
University.
The ultrastructure of the tarsUS of the cotton leaf worm
were examined in the central laboratory in Faculty of
Agriculture, Alexandria University and also in Faculty of
Science in Tanta University.
Cotton leaf mass reared under laboratory condition for
mass production of moths. The tarsus of the for-leg of the
female moths were used to study the ultrastructure of
sensil1a which can be found on each segment of the tarsus,
by using scanning electron microscope. Each sensillum was
examined to identify its characters.
For electrophysiological studies, experiments were
conducted to build up a circle which contain a silver-silver
chloride electrode and glass microelectrode and by the help
of a Bioscience cepto unit, which consists of Oscilloscope,
oscillograph, preamplifier and chart recorder.
Three salts XCI, NaCl and CaCl%
I were treated at
different concentration to evaluate their stimulation effect
on sensillum chaeticum on the tarsus of female ~ litt9rall~.
In the same time two types of sugars sucrose and glocuse
were tested.
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SUMMARY
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Three insecticides from three different groups
(pp.rmithr in) pyrethro ids, Lanna te (Hethomyl) Carbamate and
(Actellic (Pirimphos methyl» orgnaophosphorous compound were
tested at different concentrations to study the mode of
action of the tested insecticides.
Results indicated that the tarsus of the female moth for
leg is covered with four types of sensilla. The four sensilla
were identified to be sensillum chaeticum in larg number
followed in number by sensillum trichodeum, styloconica.
and squamiform structures. The first two sensilla were
chemoreceptors, while the last thrp.e sensilla were identified
as mechanoreceptors.
Electrophysiological investigation showed that
chemosensi tive hairs tested on tarsal setae of the cotton
leafworm moth were sensitive to all the three tested salts.
It is clear that the response of sensillum was very high at
concentration a , 1M, a , 25 Hand 1.5 M of CaC12 xci and NaC1
respectively.
Results also indicated that the frequency of impulses of
the tested sensillum increased successively by the increase
of concentration. Generally Ca(12 appeared to have less
stimulating activity at the tested concentration followed by
NaCl and KCl.
The response increased by the increase of concentration
of both sugar tested. While the number of spikes were 13.7 at
zero concentration of sucrose the number of spikes were 14.2,
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15.6 and 19.3 spikes at concentrations 0.0’1. 9.1 and 0’.25
respectively, The amplitude followed the same manner as did
the effect on the frequency.
Nearly same results were obtained when glucose was used
as stimulator.
All the tested insecticides tested induced hyper
sensitivity of the neurous sysbem.
In most treatment, high concentration of insecticides
resulted in marked increases in spontaneous firing, bursts of
action potentials.
Actellic (Pirimphos methyl) headed all the tested
insecticide in its stimulation effect on the nervous systems.
The treatment of both low and high doses resul ted in worked
increases in the spontaneous firing, bursts of action
potential in the first 5-29 minutes after treatment. Followed
by Lannate (M’ethomyl) where the stimulations appeared as a
repetitive firing waves. This phenomena appeared when
concentrations of 19~9, 299~ PPM were used.
Permethrin effect showed an continuous and regular hyper
activity, nearly at all the tes.ted concentrations exept the
highlest concentration, where a repetitive firing waves were
clear.