الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Find alternative compounds to control squash piercing sucking pests such as Tetranychus urticae, Bemicia tabaci and Thrips tabaci is very important to reduce many negative reflections resulted from using the chemical insecticides such as pest resistance and resurgence, adverse effects on non-target organisms including humans, natural enemies and negative environmental impacts. In the current study, evaluation of the effectiveness of plant extract such as citric acid, thymol, camphor and menthol and the most important results were as following: -I. Laboratory tests:A. Studying the physico-chemical properties of the plant extracts.a)free acidity or alkalinity.the acid ratios recorded in the tested extracts can be arranged as follows: 0.3420, 0.0500, 0.0270 and 0.01960% for the tested extracts (citric acid, menthol, camphor and thymol) respectively. The highest acidity percentage is 0.3420% for citric acid, followed by 0.0500% for menthol extract. No values of sodium hydroxide were recorded as an alkalinity ratio in the tested plant extracts.b)The suspension stability test for the locally prepared plant extracts, citric acid, thymol, camphor and menthol.The rate of attachment to citric acid in soft and hard water was 100% followed by camphor recorded the attachment rate 89.261 and 87.690% for soft water followed by hard water and then after that thymol recorded the lowest percentage of attachment 24.977% and 24.568% for soft water followed by hard water, whereas it was found that the lowest tested extract was suspended in menthol water with a value of 12.959% and 10.844% attached to hard water followed by soft water. B. Toxicity and residual effect of certain plant extracts (citric acid, thymol, camphor and menthol) on Sitophilus oryzae pests:a. Toxicity of plant extracts on S. oryzae weevil at different periods of exposure:To test the toxicity of plant extracts in the form of a dusting powder against a pest (rice weevil) S. oryzae that infects rice containers in the store using talc as a carrier on rice grains. The concentration used were of 0.5%, 1% and 1.5%, and estimating the toxicity of these concentrations during a period of seven days from the date of the translocation, as well as limiting the numbers of mortality. The highest insect mortality percentages was 20.00, 30.00, and 36.66% for thymol extract, followed by 10.00, 13.33, and 26.66% for citric acid and menthol extracts, whereas camphor was the lowest one 10.00, 16.00 and 20.00% compared to talc and control recorded 0.00% mortality after one day of treatment in order with the concentration ratios. The results also indicated that the mortality percentages for insects after two days of treatment demonstrated that the highest mortality percentages for insects is 26.66, 76.66 and 80.00 for thymol extract, followed by 16.66, 40.00 and 46.66 for camphor extract compared to talc and control in order with the concentration ratios. Whereas after three days of treatment, the results of the study recorded the highest mortality percentages of insects, 40.00, 93.33 and 96.66 % for thymol, followed by 36.66, 53.33 and 70.00% for the extracts of camphor and menthol compared to talc and control in order with the concentration ratios. After four days of treatment with plant extracts, the highest insect mortality percentages was 63.33, 100 and 100 for thymol extract, followed by citric acid 50, 73,33 and 80% compared to talc and control in order with the concentration ratios.In summary from the previous results the mortality percentage can be arranged descendingly for the plant extracts as the following thymol > camphor > citric acid > menthol.b. Residual effect of plant extracts on rice weevil at a concentration of 1.5% on the rice weevil after two months of treatment.The treatment of rice weevil with citric acid, thymol, menthol and camphor extracts at a concentration of 1.5% The result showed that after one day of treatment thymol was the most efficient plant extract as mortality percentage was 23.33 %. After 2 days of treatment also thymol showed the highest percentages of mortality was 30.00%. Also after 7 days after treatment thymol showed the highest mortality percentages 100 %. Overall thymol showed the highest general mean of mortality percentage was 61.40 % for the tested.In summary, from the previous results, it was found that the best influencing compounds that led to high mortality percentages for the weevil is a thymol extract, followed by menthol. II. Field experiments:1. Effectiveness of certain compounds against Tetranychus urticae under field conditions in squash plants during 2018 and 2019 seasons. The treatment of squash plants with plant extracts against two spotted spider mites during 2018 winter season. The result confirmed that citric acid was the most efficient plant extract at initial time as mortality percentages were 84.6, 90.1and 90.8 % for 1, 1.5, and 2 % respectively. The lowest reduction rates at initial time among plant extracts was camphor as mortality percentages were 74.7, 79.9 and 89.9 % for 1, 1.5, and 2 % respectively. Azadirachtin gives the highest reduction rat among traditional compound as mortality percentage was 94.97 % at the initial effect after one day of treatment. For the residual effect, Camphor was the most efficient plant extract as mortality percentages were 87.0, 89.10 and 90.8 % for 1, 1.5, and 2 % respectively. The lowest reduction rate for plant extract was thymol as mortality percentages were 86.40, 88.20 and 88.80 % for 1, 1.5, and 2 % respectively and azadirachtin was the highest reduction rat for traditional compound as mortality percentage was 93.87 %.For the general reduction, the best plant extract was citric acid and lowest was camphor and also the highest reduction rate for traditional compound was azadirachtin. The treatment of squash plants with certain plant extracts during 2019 summer season against the red spider mite. The result confirmed that citric acid was the most efficient plant extract at initial time as mortality percentages were 85.57, 91.20 and 91.77 % for 1, 1.5, and 2 % respectively. The lowest reduction rates at initial time among for plant extracts was camphor as mortality percentages were 74.14, 79.89 and 89.73 % for 1, 1.5, and 2 % respectively and azadirachtin was the highest reduction rat for traditional compound as mortality percentage was 95.97 % at the initial effect after one day of treatment.
For the residual effect menthol was the most efficient plant extract as mortality percentage were 87.03, 89.86 and 91.72 % for 1, 1.5, and 2 % respectively. The lowest reduction rate for plant extract was thymol as mortality percentages were 87.33, 88.20 and 88.60 % for 1, 1.5, and 2% respectively and azadirachtin was the highest reduction rat for traditional compound as mortality percentage was 94.37 %.For the general reduction, the best plant extract was citric acid and lowest was camphor and also the highest reduction rate for traditional compound was azadirachtin.