The present work was carried out to evaluate the efficacy of Agrotis segetum granulosis virus (AgseGV^EG) 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 (AgseGV^EG). Results showed that, addition of F. brightener 1% to AgseGV^EG suspension using surface contamination technique of semi synthetic diet increased the susceptibility of 3^rd and 4^th instars of A. ipsilon larvae; the LC₅₀ was 2.08×10⁸ OB / ml and 6.10×10⁸ OB/ml, respectively. The LT₅₀ values of AgseGV^EG (9.07×10¹⁰ OB/ml) +F. brightener 1% was7.67 and 7.85 days for 3^rd and 4^th instars. In addition, semi-field conditions, F. brightener 1% as sun screen enhanced AgseGV^EG persistence on Cotton foliage after spray, the calculated lethal inactivation median time for 50 % reduction in virulence (lethal median inactivation time, LIT₅₀) for 2^nd 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 AgseGV^EG+ F. brightener 1% in bran bait formulation increased mortality% of A. ipsilon in two concentrations of AgseGV^EG (9.07×10⁹ and 9.07×10⁸ OB/ ml) + F. brightener 1% and decreased the number of cut cotton plants infested with 3^rd instar larvae of A. ipsilon compared to untreated control. The damage reduction to Cotton seedlings with A. ipsilon, was 83.33% and 70% for 3^rd and 4^th instars larvae, respectively, in the AgseGV^EG (9.07×10⁹ OB/ml) + F. brightener 1% compared to control. In conclusion in  both spray and bran tested treatments larvae infected with AgseGV^EG+ F. brightener 1% died more rapidly than those infected with AgseGV^EG alone ; indicating that AgseGV^EG appears to have better potential as a control agent for A. ipsilon by adding enhancement additive.