Comparative study on the Efficacy of Agrotis segetum Granulosis virus (AgseGVEG) against Agrotis ipsilon under semi-field conditions | ||
| Egyptian Academic Journal of Biological Sciences. A, Entomology | ||
| Article 3, Volume 6, Issue 3, December 2013, Pages 21-30 PDF (194.9 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/eajbsa.2013.13225 | ||
| Author | ||
| Magda Khattab | ||
| Plant Protection Research Institute, ARC, Dokki, Giza, Egypt Department of Cutworms and Mole Cricket | ||
| Abstract | ||
| The present work was carried out to evaluate the efficacy of Agrotis segetum granulosis virus (AgseGVEG) against Agrotis ipsilon larvae in semi-field experiments using spray and wheat bran bait method. A Fluorescent brightener (Tinopal UNPA-GX) was added for enhancement of Agrotis segetum granulosis virus (AgseGVEG). Results showed that, addition of F. brightener 1% to AgseGVEG suspension using surface contamination technique of semi synthetic diet increased the susceptibility of 3rd and 4th instars of A. ipsilon larvae; the LC50 was 2.08×108 OB / ml and 6.10×108 OB/ml, respectively. The LT50 values of AgseGVEG (9.07×1010 OB/ml) +F. brightener 1% was7.67 and 7.85 days for 3rd and 4th instars. In addition, semi-field conditions, F. brightener 1% as sun screen enhanced AgseGVEG persistence on Cotton foliage after spray, the calculated lethal inactivation median time for 50 % reduction in virulence (lethal median inactivation time, LIT50) for 2nd instar larvae was0.97 or 2.27 days for virus alone-treatment and AgseGV+ F. brightener additive, respectively. The calculated potency value for F. brightener was 2.335 Fold. Mixture of AgseGVEG+ F. brightener 1% in bran bait formulation increased mortality% of A. ipsilon in two concentrations of AgseGVEG (9.07×109 and 9.07×108 OB/ ml) + F. brightener 1% and decreased the number of cut cotton plants infested with 3rd instar larvae of A. ipsilon compared to untreated control. The damage reduction to Cotton seedlings with A. ipsilon, was 83.33% and 70% for 3rd and 4th instars larvae, respectively, in the AgseGVEG (9.07×109 OB/ml) + F. brightener 1% compared to control. In conclusion in both spray and bran tested treatments larvae infected with AgseGVEG+ F. brightener 1% died more rapidly than those infected with AgseGVEG alone ; indicating that AgseGVEG appears to have better potential as a control agent for A. ipsilon by adding enhancement additive. | ||
| Keywords | ||
| cutworms; Agrotis segetum; Granulosis virus (AgseGVEG); Occlusion Bodies (OB); brightener additive; Agrotis ipsilon; Spray; Bran bait formulation | ||
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