الفهرس 
Title : Efficacy of bacillus thuringiensis and spinosad on the Egyptian cotton leaf worm, spodoptera littoralis
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Abstract
The cotton leaf worm Spodoptera littoralis, is one of the most injurious agricultural pests in Egypt. In the present study, the interaction between spinosad and Bacillus thuringiensis, using different pairings, in 3 {u036C} {u0369} and 5 {u036D} {u036A} instar larvae was determined. Activities of Ü- and Ý-non specific esterases and acetylcholinesterase (AChE) were also determined. Additionally, AChE transcript abundance using the Real-time polymerase chain reaction (PCR) was detected. The cumulative larval mortality percentages after treatments of both 3 {u036C} {u0369} and 5 {u036D} {u036A} instars with spinosad and B. thuringiensis were increased by increasing the concentrations. Spinosad was more potent than B. thuringiensis. Sequential application of these bio-insecticides, on the LC₂₅ level on 3 {u036C} {u0369} and 5 {u036D} {u036A} instar larvae, when spinosad was first applied, showed synergistic interaction and additive effect, respectively. On the other hand, when B. thuringiensis was first applied, using the same timing of application, additive interaction was observed for both 3 {u036C} {u0369} and 5 {u036D} {u036A} instars. Individual, simultaneous and sequential applications of these bio-insecticides induced variable changes in Ü- and Ý- esterases and AChE activities. Real-time PCR (qRT-PCR) revealed an increase in transcript abundance up to 2.0 folds in 3 {u036C} {u0369} instar larvae in case of sequential and simultaneous applications. Based on the results herein, integrated pest management program using spinosad and B. thuringiensis can be successfully developed for the control of S. littoralis