Large Orange Sulphur (Phoebis agarithe) life history
Large Orange Sulphur (Phoebis agarithe) Life History

Egg, 9-6-10

Day-old egg, 9-7-10

Day-old caterpillar, 9-8-10

Differences in size already noticeable on day two, 9-9-10





Mature caterpillar, but not first to pupate, 9-15-10

Chrysalis of first caterpillar to pupate, 9-15-10

Adult nearly ready to emerge, 9-19-10

Fresh male Large Orange Sulphur, 9-20-10

Blackbrush Acacia (Acacia rigidula) is host to Large Orange Sulphurs. The sulphurs are common here and Blackbrush is one of the most common bushes growing in this area of south Texas, so one would expect to find ovipositing females, eggs, and larvae fairly easily. However, after two years of failing to find any of these I caught a mating pair to obtain eggs.

I released the male after they separated and placed the female in a jar with Blackbrush and, for nectar, Coral Vine (Antigonon leptopus) - it was in bloom and very popular with the sulphurs at the time. After a couple of days, I was surprised to find eggs all over the Coral Vine flowers as well as the Blackbrush. At the time, I supposed that the female was just laying randomly because she was in a closed container. So after I released her, I kept the flowers with the Blackbrush, expecting the larvae to move to the proper host.

Unfortunately, some of the caterpillars that eclosed from the eggs on Coral Vine did not move to Blackbrush, and they died. As it turns out, this was not an accidental event. I later observed a free female ovipositing on Coral Vine flowers in my yard. I watched the eggs, and after they eclosed I never found any evidence that any of the caterpillars survived. Evidently, Coral Vine is not an acceptable host for Large Orange Sulphurs, but it must have some chemicals that encourage the females to lay on it. It appears this is a case where a non-native plant fools the butterfly.

The eggs took only 2 or 3 days to eclose. The caterpillars grew rapidly; the first pupated after eight days, and emerged five days later. Thus, some went from egg to adult in just two weeks. That is one of the shortest development cycles I have observed.

Large Orange Sulphur Page