Thermal tolerance in giant ants: how do Dinoponera quadriceps adapt to heat in different Brazilian biomes?

• Grant number: 25/01415-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2025
• End date: August 31, 2028
• Field of knowledge: Biological Sciences - Zoology - Physiology of Recent Groups
• Principal Investigator: Michael Hrncir
• Grantee: Maria Eduarda de Lima Vieira
• Host Institution: Instituto de Biociências (IB). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

As global temperatures rise, the ability to mitigate high temperatures will increasingly define predictions of animal extinction and distribution. However, there is still no consensus on the variation and plasticity of thermal traits among ant populations or their capacity to withstand thermal stress. Therefore, we propose investigating the thermoregulatory mechanisms of the Brazilian endemic ant Dinoponera quadriceps, a species that plays a significant ecological role in the Caatinga and Atlantic Forest. We will assess D. quadriceps' thermal tolerance and sensitivity through the relationship between survival time and thermal stress, and metabolic rate will be measured via CO2 consumption using a closed-circuit respirometry system. Specimens from both ecosystems will be collected in the field during daytime and nighttime and subjected to thermal stress in the laboratory to evaluate basal variation in both populations through mass spectrometry-based proteomic analysis. Finally, behavioral performance will be assessed using trajectory analysis and foraging success records. This project will pioneer the identification of molecular, physiological, and behavioral markers that indicate the adaptive capacity of D. quadriceps in different environments, as well as those associated with thermal stress. These findings will help us understand how social insect populations may face different outcomes under future climate change scenarios. (AU)