Toxicity, lifespan and motor changes in Africanized Apis mellifera exposed to insecticide fipronil and fungicide pyraclostrobin

• Grant number: 15/11332-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2015
• End date: July 31, 2016
• Field of knowledge: Agronomical Sciences - Animal Husbandry - Animal Production
• Principal Investigator: Ricardo de Oliveira Orsi
• Grantee: Aimê de Almeida Longuini
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The monoculture expansion promotes the growth of pests and diseases, and makes the agricultural systems enhance their dependence in pesticides use. The pesticides can enter in the soil-water-plant chain, representing a source of contamination to bees that collect resources, causing damage to biodiversity, reducing bees' population and cause economic losses due to decline of these pollinators. Usually the poisoning of the bees occurs during food collection, by direct contact or ingestion of contaminated resources. The objectives of this study are to evaluate the toxicity (LD50) of the insecticide fipronil (Regent® 800WG) and fungicide pyraclostrobin (COMET®); to evaluate the overall lifespan and the occurrence of motor changes of Africanized honeybees (Apis mellifera) exposed by ingestion or contact the sublethal doses of these pesticides alone or in combination. Newly emerged bees (0-24h) or foragers (over 20 days old) from five colonies will be used in the tests. The toxicity (LD50) will be assessed by tests of ingestion of contaminated food and by contact tests with different concentrations of commercial formulations of pesticides. Then, newly emerged bees will receive contaminated food with sublethal doses of pesticides to assess their lifespan. Also will be evaluated the motor activity of forager bees exposed by ingestion or contact to sublethal doses of pesticides. All tests will be performed in triplicate. The results of bees mortality obtained during toxicity tests will be used to the calculation of the LD50. The results will be analyzed by Analysis of Variance with application of the Tukey's test for mean comparison with the 5% level of significance.