Starr County Butterflies
Fresh egg, 11-27-10
Just-emerged caterpillar, 12-4-10
Day-old caterpillar is green, 12-5-10
12-8-10
12-9-10
12-14-10
Caterpillar background color is now black, 12-16-10
12-20-10
Middle instar Red Rim (below) with late instar Common Mestra (above), 12-29-10
1-10-11
1-15-11
1-23-11
Three days before pupating, 1-28-11
Front view of chrysalis, 1-31-11
Rear view of chrysalis, 1-31-11
Fresh adult Red Rim after release, ventral, 2-22-11
Fresh adult Red Rim, dorsal, 2-22-11
This study began in late November, 2010, with the capture of a female Red Rim. She produced two eggs after two days in a cage with abundant food and hostplant (Noseburn, Tragia glanduligera). On the third day, with no more eggs being produced, she was released. One of the two resulting caterpillars was raised to maturity.
The egg eclosed after seven days, and the growing caterpillar changed almost daily for the first week to ten days. In contrast, there was little visible change through the last month of the larval stage. The mature caterpillar was fascinating to view, with intricate color patterns evident beneath all the spines and knobs that decorated its body.
A potted Noseburn was the initial source of fresh food for the caterpillar. Providentially, a Common Mestra caterpillar was also feeding on this plant, giving opportunity for the side-by-side comparison of the two species that can be seen in the 12-29-10 picture. On that date the two caterpillars were about the same size (although at different stages of development). Clearly, a casual glance could easily confuse the two species.
The caterpillar was kept in an unheated room. In this environment, it experienced similar temperatures and lighting to natural conditions, but was spared exposure to extreme temperatures. In any event, it pupated before any significant freezing weather set in. During times of warmer weather, the caterpillar remained on the host plant. During colder spells, the caterpillar moved from the plant to the bottom of its container. Outdoors, one would expect this behavior to help protect a caterpillar from cold that might otherwise kill.
The caterpillar took 58 days to pupate. I feared I would have to care for the chrysalis until the following fall, but the adult emerged 21 days later, in the midst of a February heat wave (temperatures were regularly above 80 degrees Fahrenheit). The Red Rim's winter journey from egg to adult took a total of 87 days.