Short-term exposure to heatwave-like temperatures affects learning and memory in bumblebees

Area of Science:

• Ecology
• Animal Behavior
• Climate Change Biology

Background:

• Global warming is a major driver of bee declines.
• Elevated temperatures during bee activity periods are implicated, but mechanisms are unclear.
• Cognitive function is vital for bee survival, impacting foraging efficiency.

Purpose of the Study:

• To investigate if temperature-induced cognitive impairments contribute to bee declines.
• To explore the effect of short-term heat exposure on bee learning and memory.

Main Methods:

• Bees were tested on learning and memory tasks at typical summer temperatures (25°C) and elevated heatwave temperatures (32°C).
• Learning involved associating a colored light with a sucrose reward.
• Memory retention was assessed after one hour.

Main Results:

• Bees exposed to 32°C showed significant impairment in forming learned associations compared to bees at 25°C.
• Memory of learned associations was abolished in bees exposed to heatwave temperatures after one hour.
• Even short-term exposure to heatwave-like temperatures severely impacted cognitive performance.

Conclusions:

• Temperature-induced cognitive deficits are a potential driver of bee population declines.
• Heatwave events can severely impair essential insect cognitive functions.
• Findings highlight the vulnerability of bees to climate change impacts on cognition.