Butterflies and Host Plants
Ro Wauer, June 20, 2004, The Victoria Advocate, © 2004
A recent trip to Aransas National Wildlife to survey butterflies was a good reminder how some butterfly species can only be found during a brief period of time each year when their larvae (caterpillar) foodplants are available. At Aransas, a few soapberry trees were in flower at the entrance to the Rail Trail, and several of the creamy flower clusters contained feeding soapberry hairstreaks. This hairstreak can occur throughout most of Texas, although its range excludes most of South Texas, but it flies only for a few weeks each May and June.
There are several other butterflies that fly only during brief periods, but most are not so dependent upon obtaining their food from their flowering hostplant. The majority of butterflies feed on nectar that they obtain from a wide variety of flowering plants. Yet each species has one to several larval foodplants on which it lays eggs. The larvae will then consume that plant before developing a chrysalis from where the adult will eventually emerge. Larval foodplant examples include dill for black swallowtails, pipevines for pipevine swallowtails, mistletoe for great purple hairstreaks, passion vines for gulf fritillaries, Texas thistle for painted ladies, and hackberrys for snouts the emperors.
One of the more interesting host-specific butterflies is the yucca giant-skipper that lays its eggs on the tip of yucca plants. These large skippers fly only during springtime but never feed on nectar; males obtain nutrients by sipping mud. The eggs hatch within a few days and the larvae build a silk "nest" among the leaf tips where the larvae live, feed on the leaves, and grow. They eventually tunnel into the yucca roots and construct a dung-covered silk chimney-like tube near the yucca base. The larvae are able to hibernate. In spring they emerge from the silken tube as an adult giant-skipper.
Butterfly watchers learn that knowing the proper foodplants help considerably for finding butterflies. Although species like the gray hairstreak can use an enormous variety of plants, the reason that species is so widespread and common all across North America. And painted ladies are also widespread; they are commonplace all through Europe and Central and South America. All species must find their essential foodplant in order to reproduce. Milkweeds are good examples, for migrating monarchs can only survival their springtime journeys if they reproduce along the way; monarchs feed on milkweeds and milkweeds also serve as their larval foodplants.
A number of other larval foodplants in the Gulf Coastal Area of Texas include mustards for checkered whites, kidneywood for southern dogface, sennas for large orange sulphurs and sleepy oranges, blackbrush for coyote cloudywing, various oaks for Horace's cloudywing, mallows for checkered-skippers, sedges for dun skipper, and various grasses for clouded, fiery, eufala, and ocola skippers.
Anyone planning a butterfly garden, a hobby that is becoming increasingly popular, should always select their plantings to include some larval foodplants as well as flowering plants that are most likely to attract and feed the adults. The ten very best nectaring plants for South Texas, in order of importance, include crucita or mistflower (Eupatorium odoratum), cowpen daisy, tropical sage, mealy sage, frog-fruit, Texas palafoxia, palmleaf eupatorium, Mexican heather, weeping lantana, and gold lantana. A few other good nectaring plants include Mexican flamevine, milkweeds, pentas, skyflower, zexmenia, and zinnia. All of these plants and other suggestions are included in a brochure that Derek Muschalek and I wrote for the North American Butterfly Association, and available on the internet at www.naba.org.
One huge advantage of your own butterfly garden, whether it is an acre or more or simply a tiny one in a planter on your porch or deck, is that you can watch these marvelous creatures up close and personal.