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.
KEY WORDS False chinch bug, biorational insecticides, MoroccoMany members of Lygaeidae are pests of a wide range of crops (Hori et al. 2000, Sweet 2000. Populations of some species can reach damaging proportions under certain conditions, such as in hot, arid environments (Maistrello et al. 2006, Ferracini & Alma 2008. The false chinch bug, Nysius raphanus Howard (Hemiptera: Lygaeidae), is native to the United States and is considered one of the most serious Nysius spp. pests that can affect crop production in many regions, especially in arid and semi-arid areas (Capinera 2001). The false chinch bug is multivoltine with multiple overlapping generations per year (Burgess & Weegar 1986, Rijal et al. 2021, and overwinters as nymphs and adults under plant debris, weeds or rubble (Burgess & Weegar 1986, Sweet 2000, Rijal et al. 2021. It becomes active in spring when the emerging nymphs and adults begin feeding on the leaves of a suitable host (preferably a member of Brassicaceae) (Rijal et al. 2021). Eggs are deposited in soil or on suitable host plants (Rijal et al. 2021). Nymphs develop through five instars before adulthood (Rijal et al. 2021). The false chinch bug re-