Invasive Insects Differ from Non-Invasive in Their Thermal Requirements

Area of Science:

• Ecology
• Evolutionary Biology
• Entomology

Background:

• Insect invasions pose significant ecological and economic threats globally.
• Understanding species-specific traits, particularly thermal requirements, is crucial for predicting invasiveness.
• Current risk assessments may not fully capture the role of thermal physiology in insect invasions.

Purpose of the Study:

• To investigate differences in thermal requirements between invasive and non-invasive insect species.
• To determine if lower developmental thresholds and sums of effective temperatures influence insect invasiveness.
• To enhance insect invasion risk assessment by incorporating thermal traits.

Main Methods:

• Comparison of 100 pairs of related invasive and non-invasive insect species from the same continent.
• Analysis of lower developmental thresholds (temperature at which development ceases).
• Analysis of sums of effective temperatures (day-degrees required for development).

Main Results:

• Invasive insect species exhibited significantly higher lower developmental thresholds compared to non-invasive species.
• A trend towards lower sums of effective temperatures was observed in invasive species, though not statistically significant.
• A significant inverse correlation was found between differences in lower developmental thresholds and sums of effective temperatures between invasive and non-invasive species.

Conclusions:

• Higher lower developmental thresholds may be a key trait enabling insect species to invade new regions.
• Climate change may facilitate invasions by species currently limited by low temperatures.
• Understanding thermal physiology is vital for predicting future insect invasions and their potential impact.