Aqueous botanical extracts, via different extraction methods, for control of the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Abstract

Abstract Diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), is a vegetable pest of the genus Brassica worldwide. The development of new, safer bio insecticides with less negative impacts on human health, flora, fauna, and specific to the target is needed to combat this pest, particularly in small-scale organic agriculture. In this sense, the efficiency of 7 plant species in the form of aqueous botanical extracts was evaluated regarding the bio insecticide effect, using three extraction methods (orbital agitation, decoction, and infusion). There was a difference between the treatments, highlighting the decoction of Couroupita guianensis, which presented the highest efficiency (39%) for second-instar larvae of P. xylostella, followed by infusions of Codiaeum variegatum and Ruta graveolens, both with a 29% efficiency rate. The 3 extraction methods were statistically different, with decoction and orbital agitation presenting the best results.