Erythrism or erythrochroism refers to an unusual reddish pigmentation of an animal's hair, skin, feathers, or eggshells.^[1]

Causes of erythrism include:

• Genetic mutations which cause an absence of a normal pigment and/or excessive production of others^[2]
• Diet, as in bees feeding on "bright red corn syrup" used in maraschino cherry manufacturing.^[3]

Erythrism in katydids has been occasionally observed. The coloring might be a camouflage that helps some members of the species survive on red plants.^[4] 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.^[5] Erythrism in leopards is rare, but one study^[6] reported that two of twenty-eight leopards seen in camera traps in a South African nature reserve were erythristic, and the authors found records of five other "strawberry" leopards from the region.^[7]

• Erythrism in katydids