Field and Laboratory Evaluation of d-Limonene, Mineral Oil, and Potassium Salts of Fatty Acid against Nysius raphanus (Hemiptera: Lygaeidae)

Abstract

ABSTRACT The false chinch bug, Nysius raphanus Howard (Hemiptera: Lygaeidae), is a pest of a wide range of plant species. The efficacies of d-limonene (applied at 0.2, 0.3, 0.5, 1, and 1.5 g a.i./L), mineral oil (applied at 5, 8, 10, 20, and 24 g a.i./L), and potassium salts of fatty acid (applied at 0.05, 0.1, 0.2, 0.4, and 0.6 g a.i./L) against adults and nymphs (10-d-old) were evaluated in laboratory bioassays and under field conditions. Phytotoxicity of the same insecticides and doses to Portulaca oleracea L. (Portulacaceae) was also documented in the laboratory. In the laboratory topical contact toxicity bioassays, d-limonene at 1 and 1.5 g a.i./L, and mineral oil at 20 and 24 g a.i./L were the most effective treatments, causing 97% to 100% mortality at 48 h after application. In residual toxicity bioassays, d-limonene at 1 and 1.5 g a.i./L, and mineral oil at 20 and 24 g a.i./L caused 92% to 100% mortality among nymphs and adults exposed to the treated P. oleracea at 48 h after introduction. In the field experiment, d-limonene at 1.5 g a.i./L and mineral oil at 24 g a.i./L were effective in reducing 98% to 100% of adult and nymphal populations at 6–12 d after treatment. Results of this study suggested that d-limonene at 1.5 g a.i./L and mineral oil at 24 g a.i./L could be used to manage infestation by N. raphanus.