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Bug of the Week is written by "The Bug Guy," Michael J. Raupp, Professor of Entomology at the University of Maryland.

Red and green: Tailed jay, Graphium agamemnon, and cotton stainers, Dysdercus sp.

 

Plants like poinsettias and many insects derive their beautiful colors from light absorbing pigments.

 

Colors of the tailed jay butterfly are produced by thousands of scales on its wings.

For many of us red and green are colors of the holiday season. The deep green leaves and scarlet bracts of poinsettia have decorated churches and homes in Mexico for centuries, while in Europe the emerald leaves and bright red berries of holly symbolized the winter season from the times of ancient Romans and Celts. The green of leaves is created by the photosynthetic pigment chlorophyll and the reds of leaves and berries are produced by another family of pigments called anthocyanins. This is all fine for plants, but how do insects produce the magnificent colors found on their wings and bodies?  For many insects, such as the beautiful tailed jay butterfly, the striking colors on the wings are produced as light is reflected from thousands of shingle-like scales. Butterflies such as the magnificent morphos use a mechanism called interference to produce their iridescent colors. Within the scales are several tiny surfaces aligned to alter light and create specific colors. The spacing of these surfaces causes certain wavelengths of light such as blue to be reinforced and reflected, while other wavelengths such as reds are absorbed and not seen.