Selectivity of insecticides used on coffee plants on adults of the predator Chrysoperla externa (Neuroptera: Chrysopidae): implications for integrated pest management

• Grant number: 24/20332-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Alessandra Marieli Vacari
• Grantee: Leonardo Fontoura Jardini
• Host Institution: Pró-Reitoria Adjunta de Pesquisa e Pós-Graduação. Universidade de Franca (UNIFRAN). Franca , SP, Brazil

Abstract

Green lacewings of the genus Chrysoperla (Neuroptera: Chrysopidae) are among the most important and widely used natural enemies in the biological control of agricultural pests. In Brazil, the species Chrysoperla externa (Neuroptera: Chrysopidae) has been utilized in augmentative biological control programs since late 2021. Currently, approximately 840,000 hectares are treated annually with this predator, with coffee being the primary crop benefiting from its use, particularly for the control of the coffee leaf miner, Leucoptera coffeella (Lepidoptera: Lyonetiidae). Additionally, green lacewings are naturally present in coffee-growing areas in Brazil. Thus, accurately assessing the compatibility of pesticides with predator activity is essential for the success of this strategy. This study will evaluate the acute and sublethal toxicity of 15 pesticides on adult C. externa under laboratory conditions. Pesticides commonly used in coffee cultivation were selected, all of which are synthetic chemical insecticides. To assess acute toxicity, the predator will be exposed to pesticide residues on coffee plants for three days. Mortality rates and sublethal effects on the predator's reproductive capacity will be summarized into a reduction coefficient (Ex), and pesticides will be categorized according to the IOBC (International Organization for Biological Control) toxicity categories. The primary challenge of this research is to provide coffee producers with information on selective insecticides that can be used safely in coffee crops. Given the high added value of specialty coffees, this research is crucial to enable coffee growers to use products that are selective for the predator C. externa.