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Efficacy and persistence of methoxyfenozide against the cotton leafworm Spodoptera Littoralis (Boisd.) (Lepidoptera: Noctuidae)
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Abstract: Methoxyfenozide is an insect growth regulator that acts as an agonist of 20-hydroxyecdysone, a key hormone in the molting process. The purpose of these studies was to examine the effícacy of methoxyfenozide, (Runner®) to 2nd and 4th instars larvae of the cotton leafworm Spodoptera littoralis (Boisd.) and assessment the effect of methoxyfenozide on some biochemical activities on 4lh instars larvae of S. littoralis (Boisd.) and evaluate the initial as well as the residual effícacy of methoxyfenozide against these instars larvae with two rates of application 200 and 400 ml/feddan on cotton. In addition assessment the photodegradation of methoxyfenozide . It was found that the most effectíve of methoxyfenozide reached after 4 days (24 hrs on treated leaves and three days on untreated leaves), LC50 values were 0.878 and 60.785 ppm , the correspondíng LC90 reached 303.324 and 7087.305 ppm for both 2nd and 4th instars larvae, respectively. Methoxyfenozide gave a decrease in aliphatic esterase (Ali-E), alpha esterase (α-E), Aspartate transferase (AST) and Alanine transaminase (ALT) activities and an increase in beta esterases (β-E), acid phosphatase (AC-P), alkaline phosphatase (Alk-P), Invertase and amylase activities than control. The mean of mortality percentage on 2nd and 4th instars larvae were (69.07 and 89.41 %) and (30.29 and 46.72 %) from two tested rates of application with methoxyfenozide, respectively. The correlation coeffícient between the residual efficacy and time elapsed after application showed to be negative. This study was conducted in order to investigate the role of direct sunlight, ultraviolet rays (UV) and infrared rays (IR) exposure on the stability of methoxyfenozide. The rates of decomposition (K) of methoxyfenozide were 0.044, 0.024 and 0.013, the corresponding half live value (T½) of the equivalent residues toxicities were 379.872, 29.004 and 54.505 hours under exposure to direct sunlight, (UV) and (IR). So, it could be concluded that the important role that methoxyfenozide could play in developing integrated crop management (ICM) on cotton in Egypt.
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| Publication year |
2005
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| Pages |
191-203
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| Availability location |
معهد بحوث وقاية النباتات
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| Availability number |
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| Organization Name |
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| City |
القاهرة
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| serial title |
مجله الجمعية المصرية لعلم الحشرات
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| ISSN |
1110-0885
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| Author(s) from ARC |
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| Agris Categories |
Pests of plants
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AGROVOC
TERMS |
Alkaline phosphatase.
Esterases.
Insect growth regulators.
Spodoptera littoralis.
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| Publication Type |
Journal
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