Polymorphism of Colias croceus from the Azores caused by differential pterin expression in the wing scales

Jacques Hutsebaut, Hein L. Leertouwer, Doekele G. Stavenga*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
7 Downloads (Pure)


The pierid butterfly Colias croceus (Geoffroy in Fourcroy, 1785), established in the Azores archipelago, is polymorphic with six forms, C. croceus f. croceus ♂ and ♀, C. c. f. cremonae ♂ and ♀, C. c. f. helice ♀, and C. c. f. cremonaehelice ♀. We investigated the optical mechanisms underlying the wing colouration of the butterflies by performing spectrophotometry and imaging scatterometry of the variously coloured wing areas and scales. The scale colouration is primarily due to wavelength-selective absorption of incident light by pterins expressed in granular beads in the wing scales, but thin film reflections of the scales’ lower lamina and scale stacking also contribute. Three forms (croceus ♂ and ♀ and helice ♀) are consistent with the patterns of the well-known ‘alba’ polymorphism. We postulate the coexistence of a second polymorphism, ‘cremonae’, to understand the three other forms (cremonae ♂ and ♀, and cremonaehelice ♀), which are characterized by the absence of red pigment, presumably due to the differential blocking of erythropterin expression.

Original languageEnglish
Article number104114
Number of pages9
JournalJournal of Insect Physiology
Publication statusPublished - Nov-2020


  • Erythropterin
  • Imaging scatterometry
  • Spectrophotometry
  • Thin film
  • Wing colouration

Cite this