Starr County Butterflies
Fresh egg
Neonate
First instar forming nest
Second instar
Third instar
Fourth instar
Fifth instar
Pupa, fresh
Pupa, one day later
Fresh Zilpa Longtail
I have tried several times to raise Zipla Longtails. I had heard that the host in our area was Bequilla, Sesbania herbacea. This seemed reasonable, as the skipper appears regulary around Falcon Lake, where at times Bequilla grows abundantly. Eggs were easy to obtain: a captive female will readily deposit them on a netted cage. However, at most the hatchlings would nibble on the Sesbania leaves, and one or two made nests, but they did not accept the plant. At the time of this writing (February, 2023), no local host has been identified.
The butterflies are known to use Yellowhoods Nissolias) in Mexico and Arizona. Richard Boscoe reported that he had reared them on Crown Vetch (Securigera varia). So I started growing Crown Vetch from seeds (quite a challenge in South Texas heat!), and in time I obtained a Schott's Yellowhood (Nissolia schottii) vine. I was finally prepared when I had the chance to egg another Zilpa in November of 2022.
Wanting to be sure I had adequate food, I released the female after obtaining only 4 eggs. All hatched; 2 died in the first instar. The others readily established on the Nissolia and showed no interest in Crown Vetch. Unfortunately, the mature leaves of the Nissolia vine were starting to yellow and drop - my food supply was in peril. So I placed the Nissolia pot in a sunny window to encourage fresh growth, and let one eat freely on the vine, while I rationed cuttings of leaves to the smaller of the two caterpillars. (I learned later they would readily accept the yellowing leaves, but it did not occur to me at the time to try). I eventually moved both caterpillars to containers where they had Crown Vetch available as well as whatever Nissolia leaves they might eat in a day. The larger was incubated, while the smaller was kept under cooler conditions to slow its growth. The smaller caterpillar did eventually accept the Crown Vetch, and this, combined with the growth of the vine, enabled me to get both caterpillars through!
The caterpillars start out green with black heads. They are particularly colorful in the fourth instar: the body is bluish with subdorsal yellow stripes on each side. The "neck" (segment T1 of the thorax, apart from the thoracic plate) is a very bright crimson, the face has eyespots, and the "feet" are orange..
 Face of Zilpa Longtail |
The fifth instar is started a similar color to the fourth, and gradually drakened with time, especially along the back. At this stage the caterpillars appeared to grow fatter rather than longer.
The first caterpillar pupated a little over 2 months after the eggs were laid, and emerged about a month later. Winter caterpillars do take their time!