EVALUATION OF THE EFFECTS OF NEEM OIL ON THE FAT BODY AND BEHAVIOR OF THE SOLITARY BEE Tetrapedia diversipes

• Grant number: 23/14750-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Applied Zoology
• Principal Investigator: Elaine Cristina Mathias da Silva
• Grantee: Leticia Ferreira Saraiva
• Host Institution: Centro de Ciências Humanas e Biológicas (CCHB). Universidade Federal de São Carlos (UFSCAR). Sorocaba , SP, Brazil

Abstract

Neem oil is a bioinsecticide obtained from the Indian neem (Azadirachta indica A. Juss) and it is widely used in organic agriculture and home gardens. Its active principle, Azadiractina, is efficient in controlling target species; however it presents lethal and sublethal effects against non-target insects due to its actions in different systems and organs during development, as well as reduced feeding and increased mortality, which may affect bees. Bees are important pollinators acting in the maintenance of conventional and organic agricultural production. In order to evaluate the effects of Azadirachtin on native solitary bees, ecotoxicological bioassays will be performed using adult females of the species Tetrapedia diversipes exposed to neem oil. The individuals will be collected using artificial nests previously installed in the field and taken to the laboratory, where they will be kept in an incubator with controlled humidity and temperature until emergence. After emergence, each individual will be identified and separated by sex for bioassays, and relocated in pots containing food (syrup) offered ad libitum. For the bioassays, same-aged adult female individuals (1 to 3 days old) will be subjected to acute contact exposure according to the experimental groups: control (CTR), FitoNeem-I (FN-1) which represents the concentration applied in the field, and FitoNeem-II (FN-2) for a concentration 5 times higher than the one applied in the field. The behavioral analysis of all individuals will occur after 1, 24, 48, 72, and 96 hours. Then, each individual will be dissected, and the fat body will be processed for histopathological analysis. Histological sections will be submitted to morphological analysis and histochemical techniques for the detection of total proteins, lipids and carbohydrates. The results obtained will be statistically evaluated by relevant methods.