Complex life histories predispose aphids to recent abundance declines

Area of Science:

• Ecology
• Environmental Science
• Entomology

Background:

• Animals often alter feeding habits across life stages, adapting to spatiotemporal resource availability.
• Complex life histories, while advantageous, can introduce vulnerabilities when environmental change disrupts critical life-cycle timings.

Purpose of the Study:

• To investigate trait and environmental factors linked to aphid population declines.
• To analyze abundance time series data for over 300 aphid species across three global regions.

Main Methods:

• Utilized meta-dataset of aphid abundance time series from 75 sites over 10-50 years.
• Compared population trends of different aphid species based on host plant alternation strategies and agricultural status.
• Correlated population changes with environmental variables, including warming temperatures.

Main Results:

• Overall aphid abundances showed significant declines across study regions (median -8.3% to -0.1% annually).
• Aphids with obligate annual host alternation and agricultural pests experienced the most severe declines.
• Warming temperatures were associated with less severe declines or increased abundance, particularly at higher latitudes.

Conclusions:

• Host alternation in aphids may increase susceptibility to phenological mismatches with host plants, exacerbated by management practices.
• Rapid environmental change, particularly warming, is altering the ecological dynamics of complex life histories.
• While some aphid species may benefit from warming, those with time-sensitive multi-host strategies face elevated risks.