Metabolism, gene expression and performance of honey bees and silkworms well and poorly nourished and contaminated with a triple action fungicide

• Grant number: 21/00702-1
• Support type: Regular Research Grants
• Duration: November 01, 2021 - October 31, 2023
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Nutrition and Feeding
• Principal researcher: Daniel Nicodemo
• Grantee: Daniel Nicodemo
• Home Institution: Faculdade de Ciências Agrárias e Tecnológicas. Universidade Estadual Paulista (UNESP). Campus de Dracena. Dracena , SP, Brazil
• Assoc. researchers: David de Jong ; Eduardo Festozo Vicente ; Evandro Pereira Prado ; Fábio Erminio Mingatto ; James Douglas Ellis ; Jaqueline Dalbello Biller Takahashi

Abstract

The ecological imbalance inherent in the use of extensive areas with monocultures implies the demand for large amounts of pesticides. Among phytochemicals, fungicides stand out, as their recurrent use has led to the selection of resistant phytopathogenic fungi. Thus, larger doses of fungicides currently commercialized are used in the field, until products with new active ingredients are made available to farmers. A new strategy to combat phytopathogenic fungi is the formulation of fungicides with three active ingredients, aiming to control populations of fungi at different stages of the life cycle. If this alternative has been shown to be promising from an agronomic point of view, for beekeepers and sericulture farmers this measure appears to be worrying. Although such animals are insects, the main mode of action of some fungicides, the inhibition of mitochondrial respiration, has already been observed in both honey bees and silkworms, and may incur economic and socio-environmental losses. However, it is necessary to consider the nutritional status of these insects, given that nutritional deficiencies may imply greater susceptibility to stressors, such as fungicides. In our study, we will evaluate the effect of trifloxystrobin, protioconazole and bixafem, which are the active ingredients that make up a commercial fungicide used in large agricultural crops. Tests will be carried out to elucidate the effect of these active ingredients on mitochondrial bioenergetics, oxidative stress and the expression of some genes in honey bees (Apis mellifera) and silkworm caterpillars (Bombyx mori), which will receive diets of high and low nutritional value. In addition, the performance of bees as pollinating agents of soybean plants treated with the fungicide under study will be evaluated and the quality of the cocoons produced by silkworm caterpillars fed on mulberry leaves from plants treated with the triple action fungicide will be verified. Therefore, it will be possible to verify whether metabolic and gene expression alterations are less evident when the insects are fed on diets of high nutritional value. (AU)