Tea, coffee, and cocoa as ultraviolet radiation protectants for the beet armyworm nucleopolyhedrovirus

Abstract

The addition of 1% (wt:vol) aqueous extracts of cocoa (Theobroma cacao L.) (Malvales: Malvaceae), coffee (Coffea arabica L.) (Gentianales: Rubiaceae), and green and black tea (Camellia sinensis L.) (Ericales: Theaceae) provided excellent UV radiation protection for the beet armyworm, Spodoptera exigua (Hbner) (Lepidoptera: Noctuidae), nucleopolyhedrovirus under laboratory conditions. Aqueous extracts of coffee, green tea, and black tea at 0.5% provided 85-100% UV protection, whereas cocoa provided 50% UV protection. Epigallocatechin gallate (EGCG), a component of green tea, and caffeine, a component of tea and coffee, also were tested as UV protectants. Both compounds were ineffective when tested alone. When EGCG and caffeine were combined, UV protection increased in a synergistic manner, but <35% of the original virus activity was maintained. This study demonstrated that coffee was comparable to green tea and black tea as a UV protectant. Further studies should be conducted to optimize their use in biopesticide formulations.