الفهرس 
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Abstract
Studies reported herein were undertaken for two cotton growing seasons (2013 and
2014). The principal objectives of this study were to: (1) Determine the population fluctuation
of foliage feeders (sucking insect pests of cotton) and their associated predaceous insects as
well as the flower feeders (cotton bollworms), (2) Effect of weather factors on the population
of sucking insect pests, insect predators and cotton bollworms infestation, (3) Evaluate the
efficiency and selectivity effect of foliar treatment of four neonicotinoid insecticides
acetamiprid, imidacloprid, thiamethoxam and dinotefuran in comparison with the commonly
used malathion (organophosphate) and pirimicarb (carbamate) on sucking insect pests of
cotton, and the most common insect predators, Coccinella undecimpunctata L. and
Chrysoperla carnea (Stephens) under cotton field conditions, and (4) Evaluate the impact of
some biopesticides, emamectin benzoate (avermectin), pyridalyl (pyridalyl), methoxyfenozide
(diacylhydrazine, IGR ) in comparison with chlorpyrifos-methyl (organophosphate) and
methomyl (carbamate) against the spiny bollworm, E. insulana and the pink bollworm, P.
gossypiella infestation as well as the effect of these insecticides on the yield of cotton under
field conditions.
Results were reported in accordance with the objectives outlined above as follows:
1. Population density and fluctuation of common sucking insects on cotton plants
1.1. Cotton aphid, A. gossypii
1.1.1. Population density and fluctuation of cotton aphid
The population of cotton aphid, A. gossypii appeared in cotton fields between the 1st
week and mid April during both seasons of study. The pest has two periods appearance, the
first one was during April, May and June while the second was during August and September,
and disappeared completely from cotton fields during July in both seasons. During the 1st
period of appearance, the pest population increased gradually till reached its peak of 11.35
aphid/plant (Max. temp. 36.43°C, Min temp. 19.46 °C and RH 41.07%) and 3.00 aphid/plant
(Max. temp. 37.51°C, Min temp. 18.74 °C and RH 42.86%) during the 2nd and 3rd week of
May of 2013 and 2014 seasons. Then, the aphid population decreased gradually till it
vanished from cotton fields during the last half of June of both seasons. The appearance of
aphid during the 2nd period started from the 1st and 3rd week of August during 2013 and 2014
Summary
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seasons. The aphid population increased quickly to reach its maximum 0.63 aphid/plant (Max.
temp. 37.51°C, Min temp. 23.08 °C and RH 50.64%) and 3.27 individuals/plant (Max. temp.
39.26°C, Min temp. 23.34 °C and RH 52.50%) during the 3rd and 4th week of August of 2013
and 2014 seasons. The aphid population decreased then and vanished completely from cotton
field during the last half of September. The results of study showed that the aphid has two
period of appearance and the first one was longer with relatively high density.
1.1.2. Effect of some weather factors on cotton aphid population
Cotton aphid population was highly significant and negatively correlated with
maximum temperature (-0.091), minimum temperature (-0.336) and relative humidity (-0.347)
during 2013 season. Whereas, it was highly significant and negatively correlated with
maximum temperature (-0.505), significantly and positively correlated with minimum
temperature (0.016) and non significant correlated with relative humidity (0.275) during 2014
season.
1.1.3. Impact of selected insecticides on the population of cotton aphid
Results of this part of study showed that, the foliar application of neonicotinoid
insecticides acetamiprid, thiamethoxam, dinotefuran and imidacloprid caused a high
significant reduction on cotton aphid population in the cotton fields during 2013 and 2014
seasons. Thiamethoxam, dinotefuran, acetamiprid and imidacloprid caused an average
reduction percentage of cotton aphid which was 96.42, 95.94, 84.71 and 73.58 % respectively,
whereas pirimicarb and malathion showed an average reduction of 66.68 and 38.08% at
different exposure dates during 2013 season, respectively. During 2014 season, acetamiprid,
imidacloprid, pirimicarb, thiamethoxam exhibit a maximum reduction to aphid population as
100, 87.83, 80.83 and 74.74% respectively. In contrast to dinotefuran and malathion, which
showed an average reduction of 66.83 and 32.11%, respectively. In addition, the efficiency
and residual effects of these