Sexual Size Dimorphism in the Color Pattern Elements of Two Mimetic Heliconius Butterflies

Area of Science:

• Evolutionary Biology
• Entomology
• Animal Behavior

Background:

• Sexual dichromatism and body size dimorphism are well-studied in butterflies.
• Sexual size dimorphism in color pattern elements remains less explored.
• The Heliconius genus is known for coevolution between mate preferences and mimicry.

Purpose of the Study:

• To investigate sexual size dimorphism in wing color elements of Heliconius erato phyllis and Heliconius besckei.
• To analyze allometric patterns of these color traits.
• To explore correlations between dorsal and ventral wing surface element sizes.

Main Methods:

• Quantitative analysis of wing color pattern elements in Heliconius erato phyllis and Heliconius besckei.
• Allometric pattern analysis of color traits.
• Correlation estimation between dorsal and ventral wing surface elements.

Main Results:

• Three out of four color elements were larger in males for both species, with the non-dimorphic element differing between species.
• Smaller males of one species exhibited proportionally larger yellow bars.
• Correlations between dorsal and ventral wing surface element sizes were estimated.

Conclusions:

• This study provides the first quantitative data on sexual dimorphism in Heliconius coloration.
• Findings open new avenues for researching sex-related natural and sexual selection on color pattern elements.
• The results highlight the complexity of sexual selection influencing butterfly wing patterns.