Dispersal-fecundity trade-offs in wild insect populations

Area of Science:

• Ecology
• Evolutionary Biology
• Entomology

Background:

• Wing reduction is common in upland insects, often attributed to selection against flight in harsh environments.
• Previous research suggests a link between reduced wings and increased fecundity in some insect groups.
• Direct evidence for fecundity shifts tied to flight musculature and wing development is limited.

Purpose of the Study:

• To investigate dispersal-fecundity trade-offs in the subalpine stonefly, Zelandoperla fenestrata.
• To determine if reduced flight capability correlates with reproductive investment in a wild insect population.

Main Methods:

• Analyzed 450 stoneflies from 81 diverse localities.
• Measured wing length and flight muscle size.
• Quantified ovarian mass to assess fecundity.

Main Results:

• A positive association was found between flight muscle size and wing length.
• Wing length showed a negative correlation with ovarian mass.
• Flight musculature size was negatively related to ovary mass, indicating a dispersal-fecundity trade-off.

Conclusions:

• This study provides rare empirical evidence of a dispersal-fecundity trade-off in a wild insect population.
• Trade-offs involve reductions in both flight musculature and wing development.
• Flexible resource allocation may be advantageous for widespread taxa in variable environments.