Efficiency of the bioagent Bacillus thuringensis Kurstaki on the lesser cotton leafworm, Spodoptera exigua (Hb) | ||||
Egyptian Academic Journal of Biological Sciences. A, Entomology | ||||
Article 16, Volume 5, Issue 2, August 2012, Page 141-145 PDF (152.69 K) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/eajbsa.2012.14822 | ||||
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Authors | ||||
El-Banna A. A.1; Abd El-Wahab I. S.2; El-Akad A. S.1; Amin N. S.2 | ||||
1Dept. of Entomology; Faculty of science, Ain Shams University, Cairo | ||||
2Plant protection Research Institute, Agricultural Research Center, Doki, Giza. | ||||
Abstract | ||||
The present experiments were carried out at the plant protection research station, Kaha, Qalubia Governorate, Egypt to study the efficiency of the bioagent Bacillus thuringensis var. Kurstaki against the 2nd instar larvae of the lesser cotton leafworm, Spodoptera exigua (Hb). Results revealed that the 2nd instar larvae were more susceptible to B. thuringiensis towards 4th instar larvae. Accumulative mortality percentage of the 2nd instar larvae of S. exigua treated with the different concentrations of B. thuringeinsis kurstaki, increased gradually with increasing the time elapsed after treatment. There was a stronger larvicidal effect on the 2nd instar larvae giving 2.889x106 and 6.267x1013spore/ml for LC50 and LC90 respectively. The mean larval duration for both LC50 and LC90 of B. thuringeinsis var. kurstaki was elongated compared to the control treatment. Pupal duration was insignificantly affected when 2nd instar larvae of S. exigua were pretreated with LC50 and LC90 of B. thuringeinsis kurstaki. The percentage of pupation was significantly decreased than in case of the control for both treatments, respectively. On the other hand, the percentage of pupae that succeeded in surviving and reaching the adult stage decreased in case of treated larvae than in case of the control for both treatments. | ||||
Keywords | ||||
Bacillus thuringensis Kurstaki; Spodoptera exigua | ||||
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