Ruby-spotted Swallowtail (Heraclides anchisiades) life history
Ruby-spotted Swallowtail (Heraclides anchisiades) Life History

A female ovipositing in June, 2007

Eggs observed in June, 2007

Caterpillar of study, recently eclosed, 11-7-20

First instar, 11-8-20

Second instar, 11-12-20

Third instar, 11-15-20

Fourth instar, 11-20-20

Fifth instar, 11-28-20

fresh pupa, 12-1-20

pupa after 2 days, 12-3-20

Fresh adult Ruby-spotted Swallowtail, ventral view, 12-26-20

Fresh adult Ruby-spotted Swallowtail, dorsal view, after release 12-26-20

Unlike other swallowtails in our area, Ruby-spotted Swallowtails deposit large groups of eggs, and the caterpillars are gregarious in the early instars. In June of 2007 a Ruby-Spotted swallowtail oviposited on the Mexican Lime tree (Citrus aurantifolia) in our yard. Unfortunately, we were about to leave on a two-week vacation, so I was unable to rear those eggs. I would not have another shot at raising the butterfly until 2020.

On October 26, 2020, a friend found an exhausted female which he gave to me. Her abdomen was very large, obviously full of eggs, and I began feeding her in hopes she would regain strength and lay her eggs. Sadly, she was too weak and died on the 30th of the month. I decided to dissect her and remove the eggs. I was aware that the eggs of a mated butterfly do not get fertilized until the eggs are deposited. However, sometimes even before oviposition one egg is close enough to the ovipositor that it is fertile.

Fortunately, that turned out to be the case for this butterfly. One egg did indeed hatch, and I was able to rear the caterpillar successfully. I mainly fed it leaves from the lime tree, given that was a known host. I wanted to know if any native plants could serve as hosts, so I offered Baretta (Helietta parvifolia) and Colima (Zanthoxylum fagara). It did nibble on both plants, so I suspect either would prove acceptable with adequate rain. However, during this rearing no rain had fallen for some time. The lime tree was getting watered on a regular basis, so it seemed wisest to stick with it as the host plant.

As can be seen in the pictures to the right, the changes to the caterpillar in the first four instars were minor. Each instar was distinct, but the continuity with the previous stage was obvious. The last instar, therefore, stood out with the skin becoming brown and the "knobbiness" becoming more pronounced.

Face of Ruby-spotted Swallowtail

The chrysalis was the real surprise. When first formed, it looked rather plain and nondescript. After two days, though, it took on the appearance of a lichen-colored stick. The mimicry is quite remarkable, and one can imagine how this would help camouflage the chrysalis from predators. Another interesting character is that the silk that fastened the chyrsalis to the plant was black; On Christmas day the chrysalis darkened, and I was not surprised to find a fresh adult the next morning. Weather was nice and I set the butterfly free with hopes it would fly south before the next cold front blew through.

Ruby-spotted Swallowtail Page