Starr County Butterflies
Eggs, 4-23-09
Right egg eclosing, 4-25-09
4-26-09, one day old caterpillar
4-29-09, in nest
5-7-09
5-11-09
5-18-09
5-20-09; note brown neck "collar" is present through all instars
5-21-09, color changes as it begins to form pupa
Pupa, 5-22-09; note false "eyes" and whiskers
Fresh Common Checkered-Skipper, 5-29-09
Common Checkered-Skippers regularly use Threelobe False Mallow (Malvastrum coromandelianum), a common weed in Starr County. The eggs pictured were found on the fruit of the plant; this is the only time I have found them in that location. As can be seen in the second picture, the right-hand egg eclosed first, and it is this caterpillar that is the focus of the study.
Skipper caterpillars form nests by sewing leaves together. This particular caterpillar was not as careful to hide itself as some I have observed, which made photography easier. It was very pale for about two weeks, and then for the last 9 days it had the coloration seen in the 5-18 picture. A Common Sootywing caterpillar, P. catullus, looks very similar but lacks the brown collar. Of course, the two caterpillars may also be distinguished by the food plant they are found on.
The caterpillar pupated 27 days after eclosing and emerged one week later.