Pigmentation restored in mutant laboratory strain of the lady beetle Coleomegilla maculata through dietary supplementation

Authors: Allen, Margaret - Meg

Submitted to: Advances in Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/27/2016
Publication Date: 6/30/2016
Publication URL: http://handle.nal.usda.gov/10113/62773
Citation: Allen, M.L. 2016. Pigmentation restored in mutant laboratory strain of the lady beetle Coleomegilla maculata through dietary supplementation. Advances in Entomology. 4:133-140.

Interpretive Summary: Analysis of naturally occurring mutant forms of animals and plants is a fundamental step in exploring genetics and functional biochemistry. A basic step in analyzing a pigment mutation is to provide the pigment compound to a mutant strain lacking that pigment, and seeing whether the color is restored. This is called a phenotype rescue experiment. A laboratory selected mutant strain of lady beetles without red pigments was fed pigmented particles of normally colored lady beetle wings. Plant derived pigments beta-carotene and lycopene were also fed to the mutant lady beetles. Only the insect color particles restored color to the mutant beetles, and only to the wings. This demonstrates that the red insect pigment is unique, and will help scientists understand this important beneficial insect and its visually appealing colors.

Technical Abstract: A laboratory colony of Coleomegilla maculata (DeGeer), ye, selected for a pigmentation deficiency, was restored to near wild type cuticle coloration by adding crushed heads and wings of the red colored parental strain to the diet. While the wings and other colored portions of the cuticle regained the red color, the eyes of the pigmentation deficient insects were not changed from the pale mutant form. Plant derived carotenes lycopene and beta-carotene did not restore the mutant beetles to a visibly distinguishable red color. An additional pigmentation deficient mutant strain, gold, partially recovered red cuticle color when provided with diet containing pigmented insect particles. This work represents the first rescue of a color phenotype in a lady beetle.