Twintip Buckeye (Junonia stemosa) life history
Twintip Buckeye (Junonia stemosa) Life History


Egg

Hatchling
     

First instar
            

Second instar
     

Third instar
     

Fourth instar
     

Fifth instar
     

Chrysalis
     

Fresh adult Twintip Buckeye, dorsum
     

Fresh adult Twintip Buckeye (different individual from above), ventrum
 

Twintip Buckeyes are much more common near the coast, while I live at the western end of the Rio Grande Valley. So when a friend, Bill Dempwolf, offered to bring me adult females and some hostplant, I gratefully accepted. By the next day I had perhaps 3 dozen eggs, so I released the females.

The eggs began hatching after 3 days. The first instars had long setae extending from pronounced black setal bumps. In the second instar, these bumps changed into scoli, and grew with with each succeeding instar. White or tan spotting also increased with each molt until the broken stripes of the late instars were formed.

The caterpillar's development could probably be best judged by the head. Originally it was entirely black. In the third instar, a whitish triangle appeared about where a nose would be. In the fourth instar, numerous white bumps were added. In the fifth instar, the upper part of the head became red, and there was a white area just above the mouth -- giving the distinct impression of a face.

 


Face of Twintip Buckeye

Buckeye caterpillars are highly variable. I had previously found final instar Twintip caterpillars that were red where these were brown, and had more coloration on the body than those pictured here. I have pictures of Common Buckeye caterpillars that I cannot distinguish from these caterpillars. It is best to use the host plant to determine the identity of a caterpillar found in the wild. Only Twintip Buckeyes use Stemodia, and only Mangrove buckeyes use Mangrove, and both feed exclusively on their respective host plants. In fact, near the end of the study I ran low on host plant, so I offered every available plant I available that was reputed to be a Buckeye host. A couple were nibbled on, but none were accepted. (Although Stemodia keeps well, 2-3 dozen caterpillars can eat a LOT of food! In the end, I made a run to gather more Stemodia as well as release many of the caterpillars.)

I selected the adult in the dorsal view to show that some fresh individuals - few in my limited experience - may have a purple sheen on the forewing, analogous to blue-form Common Buckeyes.

The rate of development of these caterpillars was highly variable. It took just over a month for the faster-growing individuals to go from egg to adult.

Twintip Buckeye Page