Starr County Butterflies

I found some spectacular insect eggs on a vine growing by the roadside in western Starr County. The vine proved to be Serjania (Serjania brachycarpa). I had not seen eggs anything like these before, and I actually expected them to belong to some sort of beetle. However, when I was able to return to the site a week later, I found the eggs had been replaced by small caterpillars. The caterpillars proved to be larvae of the Silvered Prominent moth;  the eggs' ID is in doubt.

I brought three of the caterpillars home to raise. A branch of Serjania, placed in a soda bottle filled with water and sealed with plastic wrap, stayed fresh until all the leaves were eaten and a new branch was needed.

When the caterpillars began to wander around the aquarium in which they were housed, they were placed in a smaller container with bark chips and fresh leaves. They ignored the leaves and disappeared into the chips. After a few days, I rooted around and discovered a pupa in the nest pictured below to the right.

Egg to pupa took about 3 weeks, during which the weather was fairly warm. The first moth emerged on 12/24, about a month after the pupa was formed. That particular day was rather cool, with highs in the fifties or low sixties as I recall, and I was quite surprised to find the moth. Having obtained the desired photos, I left the container open so that the other moths could go their way unhindered when they eclosed.

[Note: This article was originally written in 2008 with the assumption that the caterpillars emerged from the blue eggs. The article has been slightly revised because I am now skeptical that the eggs were actually Silvered Prominent eggs. In January, 2010, I found eggs of similar size and shape, but gray, that proved to be ova of a caterpillar-eating bug. As the caption now suggests, I suspect the blue eggs were likewise of a species of caterpillar predator.]