Insecticide activity of extracts of Handroanthus impetiginosus on Diaphorina citri (Hemiptera: Psylloidea: Liviidae) as well as obtaining a new insecticide

• Grant number: 23/14014-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: July 31, 2025
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Alessandra Marieli Vacari
• Grantee: Júlia Lara Nogueira
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil

Abstract

The objective of this study will be to evaluate the insecticidal activity of extracts obtained from bark, flowers, leaves, fruits and seeds of Handroanthus impetiginosus on citrus psyllid, Diaphorina citri (Hemiptera: Psylloidea: Liviidae). The extracts will be obtained from the bark, flowers, leaves, fruits and seeds, using a process of cold maceration of plant parts, spraying, filtration and concentration in a rotary evaporator under reduced pressure. In order to identify the most promising extracts for the control of D. citri, preliminary tests with ethanolic extracts of bark, flowers, leaves, fruits and seeds prepared from H. impetiginosus will be carried out. The extracts will be applied on the 4 leaves close to the budding of citrus plants at a concentration of 2000 ppm (diagnostic concentration). As a negative control, distilled water and 5% dimethylsulfoxide will be used, which will be used to solubilize the extracts and as a positive control, the commercial insecticide Abamectin + Ciantraniliprole (Minecto Pro®, Syngenta) will be used. Based on the results of screening the extracts, only the most promising extracts (which will cause high mortality) will be used to estimate the LC50 and LC90 (the concentrations needed to kill 50 and 90 percent of the population, respectively). The LT50 values (the time needed to kill 50% of the population) for the most promising extract will be estimated in concentrations that will be established according to the results obtained in this research. The effectiveness of the most promising extracts in the greenhouse will be tested using a commercial insecticide based on Abamectin; Ciantraniliprole as a positive control. The synthetic chemical insecticide will be used at the dose recommended by the manufacturer (0.4ml/L), while the ethanolic extracts of H. impetiginosus will be used at the LC90 values, which will be estimated in previous tests. The intention is to obtain a new botanical insecticide that can be used in the management of D. citri.