الفهرس 
APPROVAL SHEETOnly 14 pages are availabe for public view
 |  | from | 240 |  |  |
| | | from | 240 | | |
Abstract
As a result of the economic damage caused by two rampants of the most widespread pests on orchards and what resulted from the excessive use of pesticides, safe alternatives to control such as the use of entomopathogenic fungi, plant extracts and biocides were directed to control. Accordingly, this thesis addressed four main points:
1. Pathogenicity of three entomopathogenic fungi against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae):
The use of pesticides against the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) as a tool to control the pest has become an obstacle to the fresh agricultural products export to many countries that restrict pesticides residues. The effectiveness of 3 local strains of entomopathogenic fungi; Metarhizium anisopliae,Beauveria bassiana and Paecilomyces lilacinus against the adult and immature stages of C. capitata was evaluated under laboratory conditions. Obtained results showed that M. anisopliae and B. bassiana were superior in its pathogenicity and potential to kill the pest than P. lilacinus. These results may be important to be used for the control of the pest in IPM program.
2.Potentiality of plant extracts against different developmental stages of Ceratitis capitata (Wied.) (Diptera:Tephritidae) and study its environmental persistence:
Chemicals have become a major threat to the human ecosystem and human health because of their high toxic chemical compounds, in addition to the high cost of these compounds. Recently, there has been a tendency to use plant compounds to protect crops from insect invasion, because of their low cost and because they are bio-degradable and thus are ecofriendelly.In this study, violet dough extract,V.odorata and Eucalyptus leaves extract E.camaldeulenciswere applied on immature stages(full-grown larvae and pupae)and adults of Ceratitis capitata.With different concentrations; 0.25×103, 0.5×103, 1×103,2×103and 3×103 ppm in immature stages by two methods; spray and contact treatment. The larval and pupal response to the two leave extract concentrations varied according to the method of treatment.The Mediterranean fruit fly, C.capitata one-day and eight-days old pupae were more sensitive to the Violet dough different concentrations treatments by using the spray and contact treatment methods principally at the high concentrations than full-grown larvae.In Eucalyptus leave, threre were fluctuation of mortality percentages among different concentrations.According to LC50 and LC90 calculated values,death of C.capitata full-grown larvae, one-day and eight-day pupae was more efficient by using the contact treatment method than the spray method. In adults, individuals treated with V.odorata were more sensitive and recorded higher mortality rates than that treated with E.camaldeulensis. Consequently, deformed sensillae on antennae and ommatedia were observed by scanning electron microscope on individuals treated with V.odorata.
3.Repellent effect of leaves extracts of Viola odorataLinn andEucalyptus camaldeulencis Dehnh against Eutetranychus orientalis Females (Acari:Tetranychidae) under laboratory conditions:
Brown spider mites can rapidly develop resistance to pesticides. Organic control may be considered as an alternative and eco-friendly approach. Two plant extracts were tested for their repellence against adult females of Eutetranychus orientalis(Klein).In this study, the violet leaves extract,Viola odorata L. (Violacaea) and Camphor leaves extract,Eucalyptus camaldeulensis Dehnh (Myrtaceae) have been tested as repellent agents via assorted exposure periods ( 6,12,24,48, 96,and 72hr) at five assorted doses (0.25×103, 0.5×103, 1×103, 2×103 and 3×103 ppm/L).We observed repellency effect all does and for two extracts, whereas E.camaldeulencis was proven to be a slight stronger repellent compared to V.odorata at 2×103 and 3×103 ppm/L along all exposure time. This repellence effect is due to terpenoid constituents presented in two extracts. There were significant differences between two extracts whereas the high diversity of terpenoid groups in E.camaldelensis than in V.odorata.The present work was carried out to study the behavioral effect represented in the repellence of two plant extracts on the mite,E.orientalisa pest of citrus and could be a potential alternative for the development of eco-friendly products used to control pests which is very harmful to agriculture.
3. Efficacy of Acaricides on Eutetranychus orientals(Acari:Tetranychidae) and ItsCompatibility withPredatory Mite Euseiusscutalis(Acarei:Phytoseiidae)under Field Conditions:
Efficacy evaluation of seven acaricides, i.e.Acarine (Abamectin 5% EC), Gat Fast (2% Abamectin+10%Thiamthoxam(12%SC)),OrtisSuper(Fenpyroximate 5% EC),Concord(Chlorfenapyr 24% EC),Perfect(2% Abamectin+10%Chlorfenapyr(12%EW)),Micronet S (Sulfur 80%WP) and Acarots(Fenpyroximate 5% SC) at recommended dose (RD), against the brown spider mite, Eutetranychusorientalis(Tetranychidae) and its predatory mite,Euseiusscutalis (Phytoseiidae), was applied on citrus crop in Assiut Governorate under field conditions. Three assorted exposure eras: three days, one week and two weeks, were achieved in May 2018. It was found that a total reduction rate of these 7 acaricides against E.orientalis was 88.26%,90.40%,87.99%,88.91%,88.78%,88.41% and 87.82% and againstE.scutalis was 23.69%,19.61%,14.33%,12.7%,15.52%,16.51% and 15.33%, respectively. Abamactin5% was significantly higher than other acaricides (p<0.05) followed by Fenpyroximate5%EC and Fenpyroximate5%SC.On the other hand, the rest of acaricides appeared to be insignificant (p>0.05).Acaricides can be used against E.orientalis without affecting E.scutalis where the results showed compatibility between acaricide and predatory mites in the field. For mode of action, Fenpyroximate is safer for human and animal than others because it acts as mitochondrial electron transport inhibitor with contact action. Application of serial concentrations from these compounds is recommended to reduce its toxicity in the environment.