Marius Hairstreak (Rekoa marius) Life History

Marius Hairstreak egg on Duranta, 10-27-08

Caterpillar on 2nd day (10-29); note damage on bud above the caterpillar and droppings at bud's base. The caterpillars eat round holes into the flower buds.

11-5-08: caterpillar is 9 days old and showing purple from the Duranta flowers.

11-13-08: Both caterpillars are 17 days old; the one on the right (the focus of this study) is maturing noticeably faster than the one on the left.

11-18-08: The caterpillar sewed together two leaves to form a resting place. This is the only time I have observed this behavior, and it only used the "tent" 3 or 4 days.

11-21-08: 25 days since eclosing from the egg.

11-27-08: The mature caterpillar is ready to pupate

11-29, 12-1, and 12-23-08 respectively: the pupa took four days to develop and was fully formed 33 days after eclosion. The buttefly appeared ready to emerge after 22 days in the pupal stage. However, cool weather delayed it until Christmas day.

Between 12:00 and 12:30 on 12-25-08 the butterfly emerged. Its wings are still wet. Notice the purplish sheen on the wings of the fresh Marius.

1:02 p.m. on Christmas Day: The newly emerged butterfly is ready to fly.

In the summer and fall of 2008, Marius Hairstreaks were consistent visitors to my yard and the females were regularly laying eggs on my Esperanza (Tecoma stans) and Duranta (Duranta erecta) bushes. I decided to try to raise some after I realized that most of the caterpillars were disappearing and probably being eaten by various insect predators.

The Marius larvae eat flower blooms. I began with half-grown caterpillars from the Esperanza plant, as these plants had large blooms in plentiful supply.  I added a fresh bloom or two each day to the container, and this method worked well. I raised 3 of 5 caterpillars to maturity. One that died appeared to me to be dehydrated; the other simply stopped moving after I moved it from one flower to another.

After I had gained this experience, I decided to try to raise a Marius from the egg. I wanted to be able to leave the young caterpillars on the same plant for several days, at least. I chose Duranta as the host because the cut flowers seemed to keep better than those of Esperanza. Also, I knew the larvae would take the color of their food, and I wanted to be able to compare larvae from different hosts. A comparison of Marius Hairstreaks at various stages raised on different hosts can be seen here.

After two eggs I was monitoring hatched, I cut the flower stems and placed them in a small cup of water that was covered with plastic wrap. I then inverted an empty mayonnaise jar over the stem. (I have learned the hard way that caterpillars will climb off a host plant, or climb down a plant stem and drown. Now, when I use water to keep a host plant fresh, I strip the stem and push it through the plastic wrap - see the 11/18 picture. If done properly, the caterpillar is isolated from the water. If not done properly, it can still drown itself.)

When the first stem showed signs of wilting, it was time to move the caterpillars. I fixed a new stem. I decided after I lost that caterpillar on Esperanza that it was better not to handle the small larva, so I cut away as much of the old stems as possible and laid the old on the new. The next day the caterpillars had moved to fresh flowers.

At one point, one of the caterpillars looked to me as if it might be showing signs of dehydration. I did not want to mist the plants (because of a bad experience with other caterpillars). Since the only natural moisture the caterpillars might receive was from dew, I began to occasionally replace the flower stems in the morning when the new flowers would be dew covered. This seemed to work well. To avoid the formation of mold, I would either vent or replace the mayo jar when it was covered with moisture.

I generally keep my caterpillars on the porch, where they experience the normal environment but are protected from extreme weather. Temperatures dropped into the low 40s while the larva were growing, and stayed in the low 40s for a couple of days while they were pupating. They did not seem adversely affected.