Morph-specific life-history correlations in a wing-dimorphic water strider

Area of Science:

• Ecology
• Evolutionary Biology
• Animal Behavior

Background:

• Life-history theory posits a trade-off between reproduction and survival due to varying individual investment strategies.
• This trade-off can be obscured when resource acquisition differences outweigh allocation differences.
• Polymorphic species may exhibit morph-specific life-history correlations due to distinct physiological traits.

Purpose of the Study:

• To investigate morph-specific life-history correlations in the wing-dimorphic water strider, Aquarius paludum.
• To determine how resource allocation trade-offs vary between flight-capable and flightless morphs.
• To explore the role of these trade-offs in maintaining within-species polymorphism.

Main Methods:

• Comparative analysis of life-history traits (reproduction, survival, maturation) between long-winged and short-winged females.
• Examination of individual-level correlations between survival and reproduction within each morph.
• Investigation of the potential role of wing muscle histolysis timing in long-winged females.

Main Results:

• Long-winged females exhibited a survival-reproduction trade-off: later maturation and lower daily egg production correlated with longer lifespan.
• No significant life-history trade-offs were observed in short-winged females.
• Differences in resource allocation, potentially linked to wing muscle histolysis, explained the observed trade-offs in long-winged morphs.

Conclusions:

• Morph-specific resource allocation trade-offs influence individual variation in life-history strategies.
• These morph-specific differences contribute to the evolution and maintenance of polymorphism in Aquarius paludum.
• Wing dimorphism provides a model for understanding how physiological differences shape life-history evolution.