Insect responses to heat: physiological mechanisms, evolution and ecological implications in a warming world

Area of Science:

• Environmental Biology
• Insect Physiology
• Climate Change Ecology

Background:

• Insects rely on environmental temperature for physiological regulation, making them vulnerable to global warming.
• Many insects lack the physiological tolerance to survive current maximum habitat temperatures, posing a significant threat.

Purpose of the Study:

• To review the physiological mechanisms underlying insect responses to heat and heat tolerance.
• To explore the costs and evolutionary mechanisms of insect adaptation to high temperatures.
• To highlight knowledge gaps and suggest future research directions.

Main Methods:

• Literature review of physiological mechanisms (neuronal, metabolic, thermoregulation, stress responses, hormones).
• Analysis of life-history theory to discuss costs and evolutionary drivers of heat tolerance.
• Synthesis of current understanding and identification of research needs.

Main Results:

• Physiological mechanisms of heat tolerance in insects, beyond stress responses (heat shock proteins), are poorly understood.
• Phenotypic plasticity and genetic adaptation are potential insect strategies for coping with global warming, though plasticity has limitations.
• Evidence for rapid genetic adaptation to high temperatures exists but requires further investigation across diverse insect taxa.

Conclusions:

• Integrating insect physiological data is vital for accurate modeling of species distributions and ecological interactions under climate change.
• Significant research gaps remain in understanding insect physiological responses to heat, their evolutionary consequences, and ecological impacts.
• Future research should employ experimental approaches like artificial selection and comparative analyses across different insect levels.