Determination of the number and duration of the larval stages of the stingless bee Frieseomelitta varia

• Grant number: 23/12650-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2024
• End date: December 31, 2024
• Field of knowledge: Biological Sciences - Zoology - Physiology of Recent Groups
• Principal Investigator: Flávia Cristina de Paula Freitas
• Grantee: Miguel Carvalho Lima
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 20/13719-7 - Genomic signatures of plasticity and diversity in the phenotypic development, AP.JP

Abstract

The larval development of insects is a period of several transformations and is divided into stages marked by the replacement of the cuticle (ecdyses). Cuticle replacement is associated with an increase in the width of the cephalic capsule and, as feeding is constant, the mass also changes over the course of a stage. In this way, the larva grows as the cuticle is replaced and advances in development. Each insect species has a specific number of larval stages; however the literature is not conclusive about the number and duration of larval stages of Frieseomellita varies. Therefore, the present project proposes to characterize the larval development of this species native to Brazil, which is important for plant pollination. For this, 120 to 150 larvae will be collected, and their head capsule (mm) and mass (mg) will be measured. The values will be analyzed to identify data clusters that reflect the number of larval stages. In a second step, a brood box will be adapted to monitor larval development using non-toxic dye to mark brood cells. At 4-hour intervals, cell-labeled larvae will be collected to have their head capsules and mass measured. This approach will allow measuring the duration of each stage. Furthermore, we aim to investigate the expression profile of genes related to the synthesis and degradation of juvenile hormone and ecdysone, considering the importance of these two hormones in regulating the ecdysis process. In this sense, a search will be made for genes orthologous to the genes for synthesis (farnesol dehydrogenase, farnesoic acid O-methyltransferase and methyl farnesoate epoxidase) and for degradation of the juvenile hormone (JH epoxide hydrolase and JH esterase), in addition to genes related to ecdysone (cytochrome P450 314A1, ultraspiracle and ecdysone receptor) in the genome of F. varia. The expression of these genes of interest will be evaluated by PCR. This project will characterize the larval development of F. varia by determining the number and duration of larval stages. The expansion of knowledge of the biology of native bees supports the development of programs for the conservation and sustainable management of bees. In addition, the results of this project will directly contribute to the research project supported by the Jovem Pesquisador grant (2020/13719-7), to which this project is linked