
Starr County Butterflies

Egg, 11-16-22

Neonate, 11-18-22

First instar, 11-24-22

Second instar, 12-3-22

Third instar, 12-5-22

Fourth instar, 12-13-22

Fifth instar, 12-21-22

Pupa, 12-15-22

Fresh male Pavon Emperor, dorsal view, 1-9-23

Fresh male Pavon Emperor, ventral view, 1-9-23
[This article is my informal recounting of a study that appeared in News of the Lepidipterists' Society.] Pavon Emperors are known to use Spiny Hackberry, or Granjeno (Celtis pallida). Richard Boscoe egged a female and shared with me several eggs. We both offered similarly aged leaves, he from plants in the Alamo area, and me from my home in Falcon Heights. His caterpillars thrived, while only a couple of mine established. It makes me wonder if differences in the soil affect the palatability of the plants, but that is a question that someone else will have to answer. Fortunately, the caterpillars that made it past the first instar did fine.
The first instar caterpillar had nubs that would develop into "antlers" in the second instar. These would increase in size, and the face would moderately change color, with successive molts. The second instar face was light brown toward the middle; the third black, and by the fifth instar it had stripes/hues of blue, white, and black. (See the picture below.)
![]() Face of Pavon Emperor (final instar) |
Like most Emperors, the caterpillars rested with their face pointed toward the leaf. In the first three instars, the face and abdomen were raised up at a slight angle, as is shown in the photo of the second instar caterpillar. A silk pad was sewn where the caterpillar rested; this is clearly seen in the fifth instar photo.
Three or more pairs of white-and-pink dots appeared on the backs as the caterpillars developed, with the largest mainly on the front of segment A2. This larger pair was highly variable, but by the fifth instar, it generally gave the caterpillar the appearance of eyespots. Several pupae were also marked at the same spot, although in others, such as the one pictured, there was at most a black spot.
I had not seen a male adult until I raised these. I expected the purple color of the male to depend on light angle as with the blue of Silver Emperors (in that species the iridescent blue is due to diffraction rather than pigment). However, I was surprised to observe that the purple was somewhat visible at all angles, making it much easier to get a photo that shows full the beauty of the male butterfly.