Laboratory Evaluation of Selected Spray Adjuvants as Ultraviolet Light Protectants for the Nuclear Polyhedrosis Virus of the Celery Looper (Lepidoptera: Noctuidae)²

Four spray adjuvants were tested in the laboratory as ultraviolet light (UV) protectants for the nuclear polyhedrosis virus of the celery looper, Anagraphs falcifera (Kirby) (AfMNPV), against the beet armyworm, Spodoptera exigua (Hübner). We tested a sodium lignin sulfonate (Lignosite AN®), two diaminostilbene disulfonic acid-derived fluorescent brighteners (Blankophor BBH® and Blankophor HRS®), and a nutrient-based feeding stimulant (Coax®). Lignosite AN was active as a UV protectant; Blankophor BBH, as both an enhancer and a UV protectant; Blankophor HRS, as an enhancer only, and; Coax, as a UV protectant only. Lack of an effect of Coax as a feeding stimulant may be due to the design of the bioassay, in which larvae were confined on small pieces of foliage. However, the practical utility of some, if not all, of these materials may be limited by the cost and/or bulk of the amounts required to achieve the desired effects.