|SHAPIRO, M - Clemson University|
|EL-SALAMOUNY, S - Cairo University|
|SHEPARD, B - Clemson University|
Submitted to: Journal of Agricultural and Urban Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/14/2016
Publication Date: 12/13/2016
Citation: Shapiro, M., El-Salamouny, S., Shepard, B.M., Jackson, D.M. 2016. Fruit and vegetable extracts as radiation protectants for the beet armyworm nucleopolyhedrovirus. Journal of Agricultural and Urban Entomology. 32:96-105.
Interpretive Summary: The beet armyworm is a major pest of many vegetables and field crops in the United States, and crops are sprayed excessively with insecticides to control this pest and results are sometimes unsatisfactory. Thus, there is a need for new biologically-based control tactics, such as insect viruses, for control of beet armyworms. Naturally occurring insect viruses are quite effective against beet armyworms, however, commercial virus formulations are quickly deactivated by ultraviolet light from the sun. Thus, we tested 37 extracts from fruits and vegetables for their use as ultraviolet (UV) protectants for the commercial formulation of the beet armyworm nucleopolyhedrovirus. We found that the extract from black current was the only effective formulation for protecting this insect virus from degradation by ultraviolet light in a laboratory experiment. We concluded that the extracts from fruits and vegetables are less effective than extracts from herbs and spices for protecting the beet armyworm virus from sunlight degradation.
Technical Abstract: Extracts from 37 fruits and vegetables were tested as ultraviolet (UV) protectants for the nucleopolyhedrovirus (SeMNPV) of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae). Only one extract (black currant) provided almost complete protection following ultraviolet B/ultraviolet A irradiation for 30 minutes under laboratory conditions. As a group, fruit and vegetable extracts were significantly less effective than published values for herb and spice extracts, and reasons for these differences were investigated. Based on analyses of antioxidant capacity and total phenolic content of selected plants, it was determined that: (1) herbs and spices contained much higher levels of antioxidants and phenolics than fruits and vegetables; (2) neither high levels of antioxidants nor high levels of phenolics alone could account for UV protection; and (3) selection of extracts with high levels of both antioxidants and total phenolics resulted in increased UV protection.