Starr County Butterflies
An early instar
A slightly older caterpillar. Note hole in balloon above seed where caterpillar entered.
Seed damage and frass from caterpillar
Middle instars are green rather than whitish
Another middle instar
A mature caterpillar
A side view of a different mature caterpillar
A darker form with the characteristic hairstreak diamond visible on the head
Chrysalis
Fresh Silver-banded Hairstreak, ventral, 11-1-10
Fresh Silver-banded Hairstreak, dorsal, 11-1-10
In late October, 2010, I examined several seed pods of Balloon Vine (Cardiospermum halicababum). I found several instars of Silver-banded Hairstreak larvae. These I raised, but due to constraints in that period I did not separate the pictures by caterpillar. Therefore, this photo essay is a compilation of pictures of several different caterpillars. An excellent and more complete study may be seen on the website of Jan Dauphin. It has details and insights you won't find elsewhere.
http://www.thedauphins.net/silver_banded_hairstreak_life_cycle_study.html
Balloon Vine produces 1" seed pods, or balloons, that typically have three air-filled compartments. Usually a single seed will grow in each compartment. Silver-banded Hairstreak larva enter the balloons and feed on the ripening seeds. They compete for food with other hairstreaks and certain other insects, so you are never sure what you will find when you open a balloon.
The early instars of the Silver-banded Hairstreaks were yellowish or whitish. The caterpillars became green as they matured, and one became very dark in the last instars, perhaps because it was eating older seeds. As can be seen in the picture below, the caterpillars' skin was covered with dimples, or pock marks, that gave the caterpillars a unique texture; under magnification and good light the skin had a speckled appearance.
One caterpillar pupated inside a balloon; the others on the bottom of the container.