) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
University of Baghdad
College Name
Institute of laser for postgraduate studies
Department
BIOMEDICAL APPLICATION DEPARTMENT
Full Name as written
in Passport
Rana Riyadh Khaleel
e-mail
rriydh@yahoo.com , rana@ilps.uobaghdad.edu.iq
Career
Assistant Lecturer
/
Master
/
Lecturer
Assistant Professor
Professor
PhD
Thesis Title
Biological Effects of N2 and He-Ne Lasers on the Old World Screw -Worm
Fly Chrysomya bezziana Villeneuve (Diptera: Calliphoridae)
Year
2001
Abstract
The biological and genetical effects of nitrogen laser and helium neon laser on the old world screw - worm fly, Chrysomya bezziana
Villeneuve were studied, using the egg and pupa (with different ages 1,2,3,4
and 5 days) stages. Then, the effects on some biological parameters for adults,
which produced from irradiated eggs and different pupal ages, were also
investigated.
The egg and pupal samples were obtained from the culture which
rearing under adequate laboratory conditions. Pulsed N2 - laser (Molectron
UV, 24) with (337.1) nm wavelength, 1.5 millijoule pulse energy, 10
nanoseconds pulse width and repetition rate range of (1-50) pulse/second
was used. In addition to N2 - laser, the continuous He - Ne laser system
(spectraphysics) with (632.8) nm wavelength and power 1 milliwatt, was also
used in this investigations.
Irradiation of eggs by N2 - laser with repetition rate (10,20 and 30)
pulse / second and for (2,4 and 6) minutes in their respective order was
studied. After exposure to laser beam egg hatch percent, larval period, number
of pupae, pupal period, number of normal adults, life span of adults (male and
female), and sex ratio were examined. Our results showed that N2 - laser have
a significant effect on the reduction of egg hatch percent, number of pupa,
number of normal adults and life span of males and females. For example, the
egg hatch percent was 88.72% in the control group and became 33.72% after
treatment with 82.55% J/cm2 energy density for 6 minutes exposure time.
Also the results showed a significant effect of N2 - laser on duration of pupal
period. It was increased from 7.21 days in the control group to 9.74 days when
exposed to 27.52 J/cm2 energy density for 2 minutes exposure time. The effect
of N2 - laser on some biological parameters of adults (total number of eggs, egg
hatch percent, larval period, number of pupae, pupal period and sex ratio),
which produced from irradiated eggs of Ch. bezziana, were studied. The
results showed that N2 - laser have a significant effect in reducing the total
) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
number of eggs, egg hatch percent and number of pupa. For example, the total
number of eggs was 7607.50 in the control group then became 113.50 after
82.55 J/cm2 energy density for 6 minutes exposure time. Furthermore, N2 laser has a significant effect on the duration of larval and pupal periods. For
example the larval period was 6.91 days in the control group and became 9.65
days after treatment with 82.55 J/cm2 energy density for 6 minutes exposure
time.
On the other hand, irradiation of eggs by He - Ne laser with power 1
milliwatt and for (5,10,15 and 20) minuets was carried out. The same
parameters that examined when the eggs which exposed to N2 - laser was
examined here. The results illustrated that He - Ne laser has a significant effect
on the egg hatch percent, number of pupa, number of normal adults and life
span of males and females, for example the egg hatch percent was 87.38% in
the control group and decreased to 61.68% after exposing to 6.12 J/cm2
energy density for 20 minutes exposure time. Moreover, the effect of He - Ne
laser on some biological parameters for adults, which produced from
irradiated eggs were carried out. The results showed that He - Ne laser has a
significant effect on the reduction of total number of eggs, egg hatch percent,
and number of pupa. For example, the total number of eggs was 3737.25 in
the control and reduced to 1133.25 after 6.12 J/cm2 energy density for 20
minutes exposure time. Moreover this type of radiation has a significant effect
on the duration of larval period which increased from 8.82 days in the control
group to 10.29 days after 6.12 J/cm2 energy density for 20 minutes exposure
time.
Irradiating different ages of pupa (1,2,3,4 and 5) days by N2 - laser
was carried out. Posterior dorsal region of individual pupae was irradiated
with repetition rate (10,20 and 30) pulse/ second for (10,30 and 60) seconds.
The percent of adult emergence, pupal period, life span of males and females
and sex ratio were examined for each treatment. The results showed that the
N2 - laser beam has a significant effect on the adult emergence and life span of
males and females in the younger pupa while the effect was lower on the older
pupae. For example, the adult emergence was reduced from 92.00% in the
control group to 61.00% after exposing 1- day pupae to 6.37 J/cm2 energy
density for 30 seconds exposure time and to 51.00% after 38.22 J/cm2 energy
density for 60 seconds exposure time in comparison with irradiating 4 and 5
days old pupae. The adult emergence was 97.00% in the control group and
reduced to 89.00% after irradiating 5- days old pupae by 6.37 J/cm2 energy
density for 30 seconds exposure time and to 76.00% when irradiating 4- days
old pupae with the same dose. In addition the N2 - laser beam has a significant
effect on the pupal period and it was increased from 7.11 days in the control
group to 8.48 days after irradiating 1- day pupae with 6.37 J/cm2 energy
density for 30 seconds exposure time. Irradiating 2- days pupae the pupal
period was 8.02 days after 30 seconds exposure time with 19.11 J/cm2 energy
density. However irradiating 5- days old pupae the pupal period was
significantly reduced from 7.11 days in the control group to 5.23 days when
exposed to 6.37 J/cm2 energy density for 30 seconds exposure time. The effect
of N2 - laser on some biological parameters of adults, produced from
irradiated different pupal ages, was also investigated. These parameters were
) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
total number of egg, egg hatch percent, larval period, number of pupae, pupal
period and sex ratio. The results showed that the N2 - laser has a significant
effect and causing reduction in the total number of eggs, egg hatch percent
and number of pupae. For example, number of pupae was reduced from
2581.50 in the control group to 25.00 when irradiating 1- day pupae with
38.22 J/cm2 energy density for 60 seconds exposure time. While irradiating 5days pupae, the number of pupae was ranged from 3681.50 in the control
group to 269.50 at 38.22 J/cm2 energy density.
Besides, irradiating pupae (individually) with different ages (1,2,3,4
and 5) days by He - Ne laser, at the posterior dorsal region for (5,10 and 15)
minutes exposure time gave the same response as in N2 – laser tratment. The
results showed that the He – Ne laser beam has a significant effect and causing
reduction in the adult emergence and life span of males and females. The
results also indicated that the old pupae was less sensitive than the younger
pupae to He – Ne laser. For example, the adult emergence was reduced from
90.33% in the control group to 51.67% when irradiating 1- day old pupae
with 12.6 J/cm2 energy density for 15 minutes exposure time. Furthermore,
when irradiating 4 and 5 days old pupae the adult emergence was 58.34 after
12.6 J/cm2 energy density and 65.00% for the same treatment respectively.
However He – Ne laser has a significant effect on the pupal period which
increased from 8.16 days in the control group to 11.39 days when 1- day old
pupae irradiated with 12.6 J/cm2 energy density. Moreover there is no effect
illustrated when irradiating 5- days old pupae by He – Ne laser at any energy
densities, but when irradiated 2- days pupae the pupal period was 10.72 after
exposed to 12.6 J/cm2 energy density, while it was 11.68 when irradiated 4
days old pupae with 8.4 J/cm2 energy density. The effects of He – Ne laser on
some biological parameters of adults produced from different pupal ages were
studied. The results indicated that the He – Ne laser has a significant effect on
the total number of eggs produced from irradiating 1,2,3,4 and 5 days old
pupae, egg hatch percent and number of pupae. For example, the total number
of eggs laid was 2135.00 in the control group then reduced to 261.00 at 12.6
J/cm2 energy density for 15 exposure time when irradiating 1- day old pupae.
While in case 4 and 5 days old pupae the total number of eggs were 595.00
and 646.50, respectively after exposing to 12.6 J/cm2 energy density. He - Ne
laser was significantly increased larval period when irradiated only 1 and 2
days old pupae, it is ranged between 9.50 - 9.17 after exposed to 10 minutes
exposure time with 8.4 J/cm2 energy density.