Our final unit this year is butterflies. Over the next week or so, as we wind down the Pathfinder year, we will share a bit about a few local butterflies, and encourage our SAIL supporters to go out and find some butterflies yourself while enjoying nature.
Central Texas hairstreak butterflies are relatively small, somewhat triangular in outline (when their wings are folded, which is how you will most often see them), and range from shades of pale gray through green to darker browns. But don’t let this boring description fool you. Hairstreaks have a few very interesting adaptations for survival.
The larvae (caterpillars) are myrmecophilic (lovers of ants), and have a commensal (mutually beneficial) relationship with ants. They secrete sweet “honeydew” which the ants eat, and in return, the ants protect the tiny caterpillars from predators.
The adult hairstreaks exhibit automimicry (imitate part of their own body), and have a false head that can startle smaller predators or confuse larger ones. At the end of their wing, they often have a large, obvious spot that resembles an eye, and the wings end in tiny hair-like “tails" that look like antennae. When they alight, they may raise the false head higher, and move their wings about, drawing attention to the wrong end. It is not unusual to find hairstreaks with missing bits of the end of their wings - proof the strategy sent the predator in the wrong direction.
Finally, for many species neither the caterpillars or the adults are particularly picky about their food sources, meaning that they can readily adapt to changing environmental conditions, and move into areas other butterflies may find more challenging.
The larvae (caterpillars) are myrmecophilic (lovers of ants), and have a commensal (mutually beneficial) relationship with ants. They secrete sweet “honeydew” which the ants eat, and in return, the ants protect the tiny caterpillars from predators.
The adult hairstreaks exhibit automimicry (imitate part of their own body), and have a false head that can startle smaller predators or confuse larger ones. At the end of their wing, they often have a large, obvious spot that resembles an eye, and the wings end in tiny hair-like “tails" that look like antennae. When they alight, they may raise the false head higher, and move their wings about, drawing attention to the wrong end. It is not unusual to find hairstreaks with missing bits of the end of their wings - proof the strategy sent the predator in the wrong direction.
Finally, for many species neither the caterpillars or the adults are particularly picky about their food sources, meaning that they can readily adapt to changing environmental conditions, and move into areas other butterflies may find more challenging.
We have several hairstreak butterflies here in Central Texas, but perhaps the most common is the Gray Hairstreak (Strymon melinus). It is a pale gray with a bright orange wing spot, with white, black, and orange wing markings. Similar at first glance is the Oak Hairstreak (Satyrium favonius), but it is more brown than gray, has a slightly different pattern of dashes on its underwing, and the larvae prefer oaks.
Our largest is the Great Purple Hairstreak (Atlides halesus), which is blue above (most of our hairstreaks are dull above), and express aposematism (warning coloration), with the bright orange-red on their abdomen signaling they are unpalatable. Their larva feed exclusively on mistletoe, and thus may carry some of the toxins of that plant.
Another common local hairstreak is the Juniper Hairstreak (Callophrys gryneus), often a rich green and reddish-brown. As their name implies, their larvae eat Eastern Red Cedar (Juniperus virginiana) and Ashe Juniper (Juniperus ashei) (our local “cedar”), and the caterpillars are hard to find, as they blend in well with their favorite foodstuffs.
During your next walk, keep an eye out for these attractive and adaptable Lepidoptera, and see if you can tell their head from their tails!
Our largest is the Great Purple Hairstreak (Atlides halesus), which is blue above (most of our hairstreaks are dull above), and express aposematism (warning coloration), with the bright orange-red on their abdomen signaling they are unpalatable. Their larva feed exclusively on mistletoe, and thus may carry some of the toxins of that plant.
Another common local hairstreak is the Juniper Hairstreak (Callophrys gryneus), often a rich green and reddish-brown. As their name implies, their larvae eat Eastern Red Cedar (Juniperus virginiana) and Ashe Juniper (Juniperus ashei) (our local “cedar”), and the caterpillars are hard to find, as they blend in well with their favorite foodstuffs.
During your next walk, keep an eye out for these attractive and adaptable Lepidoptera, and see if you can tell their head from their tails!
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