Erythrism (unusual reddish pigmentation)
Causes of erythrism include
- genetic mutations which cause an absence of a normal pigment and/or excessive production of others
- diet, as in bees feeding on maraschino juice
Erythrism in katydids has been occasionally observed. The coloring might be a camouflage that helps some members of the species survive on red plants. There is also consensus that the erythristic mutation is actually a dominant trait among katydid species, albeit a disadvantageous one, due to the overwhelmingly green coloration of most foliage. Hence, most pink or otherwise vividly colored katydids do not survive to adulthood, and this observation explains their rarity.