Variations on a Theme: Chrysalis Colors

Green, white and pink chrysalis color variants,
pupated within 24 hours of each other. Caterpillars reared together

The Queen butterfly (Danaus gilippus) is known to have green, nearly white or pink chrysalides. Right now, we have all of these in our Rearing Lab. The chrysalides pictured here formed from caterpillars that had been reared together on the same food and under the same conditions.

These chrysalis formed just inches away from each other and all three colors were found hanging from the black plastic edge of the rearing container. These color differences are common among Queen butterflies.

I have not been able to find much research on these color variations among Queen butterflies and why they exist. If you know of any research on this subject, please do let us know in the comments.

Pale green, purple and green Queen chrysalis variants, pupated within 24 hours of each other. Caterpillars reared together

The Monarch butterfly (Danaus plexippus) is mostly known to have a green chrysalis with remarkable golden accents. However, butterfly grower Jodi Hopper of Wish Upon a Butterfly from New Castle, PA found a line of monarchs that made a golden yellow chrysalis in the Spring of 2011. She sent eggs to Edith at Shady Oak Butterfly Farm and also to Dr. Chip Taylor at Monarch Watch. Both sets of eggs were successfully reared and also made a golden yellow chrysalis. This line was named OPY for “Orange Pink Yellow” and is currently being studied by Monarch Watch.

Photo graciously provided by Edith Smith of Shady Oak Butterfly Farm. Visit them here on Facebook or check out Edith’s web page, Butterfly Fun Facts.

Color with a Purpose

Black Swallowtail (Papilo polyxenes) chrysalis can be found in a range of colors from a vibrant green to a deep brown. Dr. Jonathan Neal, an Associate Professor of Entomology at Purdue University, has worked with this species to find out what causes this variation. Research found that the photo receptors (stemmata) of the caterpillar can detect the dominant color of the surroundings as it begins to pupate.

 

Dr. Neal writes: “The color triggers or inhibits the release of a hormone that controls pupal coloration. High levels of hormone will produce a brown pupa, low levels produce a green pupa. Injection of caterpillars on a green background with a nerve extract from caterpillars that are on a brown background will produce brown pupae.”

By matching the color of the surroundings, a chrysalis gains better camouflage and has an increased chances of survival. You can read more about this topic at Dr. Neal’s blog: Living with Insects.

Other Florida swallowtail species such as Polydamas Swallowtails (pictured eelow, photo by TJ Couch), Pipevine Swallowtail and Spicebush Swallowtail exhibit a similar range of colors in their chrysalides.

Some Other Variable Species

Cloudless Sulphur: Both of these chrysalis belong to Cloudless Sulphur (Phoebis sennae)butterflies. Although the caterpillars were reared on the same host plant, in the same ten gallon rearing container and made their chrysalis within a foot of each other one is green and the other is nearly pink.

White Peacock: With this species I have found a chrysalis color range that includes several shades of green, dull brown, and a deep and rich black. Green chrysalis were generally found among fresh foliage while the brown chrysalis were found on the edges of the rearing container or in browned foliage. The deep black pupa were generally found very low on the host plant, close to the black muddy water in which the White Peacock host plant, Water Hyssop, tends to grow in pond edges.

 
Phaon Crescent: The chrysalis of the Phaon Crescent pictured here show two distinct color variations for the species which help them to better camouflage in the wild. The lighter color chrysalis was tucked in between some dried Frogfruit leaves that were nearly an identical color to the chrysalis. The second chrysalis was positioned low on a stem near to the muddy soil and so well mimicked to color of the mud that I did not see it until I removed the entire stem from the enclosure and laid it on the silver lab table.