Starr County Butterflies
Egg, 10-10-09
Day-old, 10-14-10
10-16-10
10-18-10
10-21-10
10-23-10
Mature caterpillar, 6-7-10
Mature caterpillar, 10-26-10
Caterpillar #2, brown form, 10-26-10
Face of Caterpillar #2, 10-27-10
Chrysalis #1, 10-27-10
Chrysalis #2, 10-31-10
Ventral of first adult, 11-2-10
Dorsal of second adult, 11-3-10
A wet September produced a bumper crop of Brush Noseburn (Tragia glanduligera) in a nearby arroyo. I followed a female Common Mestra around as whe deposited eggs on various vines. The eggs were placed in seeming random fashion: on seeds, under leaves, and on new leaves. After I had watched her a while, I went back to some of the plants I had seen her visit and collected three eggs. The eggs I collected were most likely laid by this female, and if so they took only four days to eclose.
The false antennae on the head appeared in the second instar, and seemed to grow with every molt. The 10-26-10 picture of the brown caterpillar shows a typical resting position: the face is pressed to a leaf or branch, and the "shoulders" and rump are raised up a little. In photos or in hand, the caterpillars do not appear highly camouflaged, but they blend in amazingly well on the plant: I often thought I had lost one or another of the caterpillars, only to discover it was right in front of my eyes. Also, larger Mestra caterpillars could easily be confused with smaller Red Rim larvae - examine them carefully if you are seeking one or the other.
The caterpillars pupated after about 2 weeks and emerged a week later.