Xami Hairstreak (Callophrys xami) life history
Xami Hairstreak (Callophrys xami) Life History

Egg, 11-28-14

Entry to Sedum sepal

First instar, 12-6-14

Second(?) instar, 12-16-14

Third instar, 12-23-14

Final instar, 12-31-14

Pupa, 1-12-15

Fresh adult Xami Hairstreak, ventrum, 208-15

In late November I visited a site where Xami Hairstreaks were known to be found. Other butterflies were about, but I was on location a couple of hours before I saw my first hairstreak. If was a nondescript gray butterfly, but it didn't act like a Gray Hairstreak, so I followed it on the chance it might be something unusual. Much to my surprise, when I got a good look, it turned out to be a Xami. There was not a green scale to be seen, but the silver pattern was (barely) visible. As the day wore on I found others in better condition, but this first was the prize: she provided the eggs of this study.

The Xami Hairstreak's host plant in the Rio Grande Valley is Texas Sedum (Lenophyllum texanum). These were in full bloom, so I offered the female flower stalks as well as leaves. She preferred the flower stalks for oviposition, with eggs primarily being tucked into the blossoms. The first instars soon burrowed into the sepals of the sedum blossoms, and that was the last I saw of the caterpillars for about a week. (For that reason, I did not observe the first molt, so I cannot be absolutely certain I have the instars correctly identified. To label the latter stages, I worked backward from the final instar on the assumption that Xamis, like most hairstreaks, have four instars.)

As the caterpillars grew, they began to feed inside the host leaves. Sedum is a succulent with very thick leaves. The caterpillars normally entered and ate all the insides of a leaf before moving to the next, leaving the hull behind. The cavity where the caterpillar was residing often filled with fluid, so much so it was surprising the larvae did not drown. The caterpillars consumed far more leaf material than I expected; perhaps this was compensation for eating leaves so full of water.

Winter growth is always slow; the caterpillar stage alone lasted longer than a month. I suspect that the larvae overwinter in the wild. These pupated in mid-January, with the adults appearing about a month later. And in the Rio Grande Valley, that put them emerging just in time for spring.

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