الفهرس 
INTRODUCTION AND AIM OFOnly 14 pages are availabe for public view
 |  | from | 187 |  |  |
| | | from | 187 | | |
Abstract
The present thesis deals with study of the effect of the four
plant oils, Lupinus sp., Citrullus colocynthis, Eruca sativa and
Lactuca sativa with different concentrations on the third instar larvae
and pupae of Culex pipiens .
The obtained results were summarized as follow:-
1. Susceptibility of Culex pipiens larvae to the plant oils:-
- All the four plant oils tested showed that the mortality
percentages increased with increasing of the concentrations at the
same time period.
-At the same concentration level the mortality percentages
increased gradually with increasing of the exposure periods.
-The highest mortality percentage (100%) was obtained by the
concentrations of 40 μl/ml after 24 hrs., 60 μl/ml after 84 hrs., 160
μl/ml after 120 hrs. and 280 μl/ml after 84 hrs. by the plant oils
Lupinus sp., Citrullus Colocynthais, Eruca sativa and Lactuca
sativa , respectively .
- Lupinus and Citrullus colocynthis oils had a high significant
effect on the mortality of larvae (P<0.01).
Summary
- 142 -
- Eruca sativa oil had a high significant effect (P<0.01) at the
high concentrations of 160,200,240,280 and 320 μl/ml.
- Lactuca sativa oil showed a highly significant effect (P<0.01)
at the highly concentrantions of 280 and 320 μl/ml.
- The LC50 and LC90 values were 0.29 and 1.02 μl/ml, 4.70
and 43.90 μl/ml, 79.80 and 154.90 μl/ml and 119.00 and 237.90
μl/ml by Lupinus sp., Citrullus colocynthis, Eruca sativa and
Lactuca sativa, respectively.
2. Susceptibility of Culex pipiens pupae to the plant oils:-
- All the four plant oils showed that the mortality percentages
increased with increasing of the concentrations at the same time
period.
- At the same concentration level, the mortality percentages
increased with increasing of the experimental periods.
- The highest mortality percentages (100%) was obtained by
the highest concentration of Lupinus oil (40 μl/ml) after 72 hrs.,
meanwhile the highest concentration of Citrullus colocynthis oil (60
μl/ml) only caused a pupal mortality of 56.67% after 60 hrs.
- In case of Eruca sativs oil, the highest mortality percentages
(100%) was caused by the concentrations of 200, 240, 280 and 320
μl/ml after 108, 84, 72 and 60 hrs., respectively.
Summary
- 143 -
- The lethal concentration (100%) was caused by Lactuca
sativa oil with the concentrations of 240, 280 and 320 μl/ml after 96,
84 and 72 hrs., respectively.
- Lupinus oil showed a high significant effect on the pupal
mortality (P<0.01) at all concentrations tested expect the lowest
concentration of 0.6 μl/ml.
- Citrullus colocynthis oil affected significantly the mortality
of pupae (P<0.01) at all concentrations tested expect the
concentrations of 1.25 and 2.5 μl/ml.
- A high significant effect on the pupal mortality (P<0.01) was
obtained at all concentrations of Eruca sativa oil expect the
concentrations of 80 and 160 μl/ml.
- Lactuca sativa oil showed a high significant effect on the
pupal mortality (P<0.01) at the high concentrations of 200, 240, 280
and 320 μl/ml.
- The LC50 and LC90 values were 0.31 and 0.94 μl/ml, 18.52
and 114.56 μl/ml, 70.10 and 150.80 μl/ml and 138.70 and 199.75
μl/ml by Lupinus sp., Citrullus colocynthis, Eruca sativa and
Lactuca sativa, respectively.
Summary
- 144 -
3. Biological studies on the effect of plant oils on
Culex pipiens larvae :-
In this study , the third instar larvae were exposed to the
botanical oils (Lupinus sp. , Citrullus colocynthis , Eruca sativa and
Lactuca sativa) at the concentrations of 0.05, 0.1 and 0.6 μl/ml.
Larval and pupal durations, pupation, adult emergence,
malformation , sex ratio , adult longevity , fecundity and fertility
were studied.
A- larval and pupal durations :
- The four plant oils increased the larval and pupal durations at
all concentrations tested.
- The increase of larval duration was high significant (P<0.01)
at all concentrations used by Lupinus oil.
- In case of Citrullus colocynthis oil, the larval durations
increased significantly (P<0.05) at the high concentrations of 0.1 and
0.6 μl/ml.
- Eruca sativa and Lactuca sativa oils had non-significant
increase effect on larval duration.
- The pupal durations had non-significant increase at all
concentrations used by the four plant oils.
Summary
- 145 -
B- Pupation and adult emergence :-
- The four plant oils showed a very high significant reduction
(P<0.001) in both pupation and adult emergence percentages at all
concentrations tested.
- Lupinus oil had the highest reduction effect on both pupation
and adult emergence, followed by Citrullus colocynthis oil.
C- Sex Ratio :-
- Lupinus oil had a remarkable increase towards the male sex
at the highest concentration of 0.6 μl/ml (1 female : 1.8 male).
- A slight increase towards the female sex at all concentrations
used by Citrullus colocynthis and Eruca sativa oils occurred.
- Lactuca sativa oil had a sharp increase towards the female
sex at all concentrations tested.
D- Adult malformation :-
- The four plant oils had a very high significant increase effect
(P<0.001) on adult malformation at all concentrations used.
Summary
- 146 -
E- Adult longevity:-
- Lupinus oil had a very high significant reduction effect
(p<0.001) on female longevity while the male life span decreased
significantly at 0.05 probability level.
- Citrullus colocynthis oil had a very high significant
reduction effect (P<0.001) on female longevity at the high
concentrations of 0.1 and 0.6 μl/ml while the lowest concentration of
0.05 μl/ml reduced non-significantly the female longevity.
- All concentrations used by Citrullus colocynthis oil reduced
non-significantly the male life span.
- Eruca sativa and Lactuca sativa oils decreased nonsignificantly
the longevity of both females and males at all
concentrations tested.
F- Fecundity and Fertility:-
- The four plant oils had reduction effect on fecundity and
fertility at all concentrations used.
- This reduction effect was significant either in both or one of
them.
- Fecundity and fertility decreased with increase the
concentrations tested for all plant oils.
Summary
- 147 -
- The botanical oils exerted a strong effect on the fecundity
when the females were treated, but In case of treated males, the
reduction effect of plant oils on fertility was high.
4 . Comparative study of the biological effects of the four
plant oils on Culex pipiens:-
A- Mortality of immature stages :-
- The comparison between the lethal effects of plant oils on
the immature stages was based on LC50 and LC90 and the
concentrations caused maximum mortality of both larvae and pupae.
- Lupinus oil had the lowest concentration (2.5μl/ml) caused
the highest mortality of larvae and pupae (100%).
- Lupinus oil was the most effective plant oil as it killed the
larvae and pupae with lowest values of LC50 and LC90.
- It followed by Citrullus colocynthis, Eruca sativa and
Lactuca sativa.
B- Effect on different biological aspects :-
The comparison between the effects of the four plant oils
tested on different biological aspects of Culex pipiens depended on
the deviation percentages from the controls after exposure the third
instar larvae to the highest concentration 0.6 μl/ml.
Summary
- 148 -
- The reduction effects of Lupinus oil on the percentages of
pupation (48.33%), adult emergence (53.33%), female longevity
(61.03%), male longevity (36.4%), fecundity of treated female
(63.90%) and fertility of treated male (52.04%) were greater than
those recorded by other plant oils.
- Lupinus oil increased both larval and pupal durations with
the highest increase percentages.
- It had a very high significant effect (P<0.001) on adult
malformation.
- It was followed by Citrullus colocynthis oil.
- Eruca sativa and Lactuca sative oils had the lowest effect on
the different biological aspects of Culex pipiens.