Host plants are just one part of building habitat into the landscape. In biology the term”host” frequently means the organism that a parasite lives off of. But in the context of landscape “host plant” refers to those species that support the larval stages of butterflies and moths. When you imagine a butterfly garden, you might be inclined to think of beautiful borders full of purple, blue, white, yellow and orange blooms.
Open blooms, with bright color and little scent are the classic butterfly attractors. But these are the nectar plants that sustain the adult butterflies.The larvae frequently need a different suite of species to develop.It is surprising to find that a number of grasses and trees are important as host plants. It is also encouraging to discover that a number of species common in the landscape or easily available are equally important to a number of butterfly species.
Juniperus ashei (cedar), the bane of allergy sufferers, is important in the life cycle of the Olive and Juniper Hairstreak butterflies, as well as providing nesting material for the Golden cheeked warbler and berries for a variety of birds. Several of the oaks (e.g. Blackjack, Post Oak, Shumard oak) also play host to specific species, for example the Chinquapin oak (Quercus muehlenbergii) feeds Horace’s Duskywing butterflies and provides acorns for squirrels and birds.
Quercus virginiana (Southern live oak), that graces many landscapes in Austin, is simultaneously providing home to small mammals and songbirds while providing sustenance for Horace’s Duskywing and the Northern White M hairstreak butterflies.
A variety of Skipper butterflies (see identification of butterflies and moths of north america) utilize different grasses as larval host plants. Common prairie grasses such as little bluestem (Schizachyrium scoparium), Big bluestem (Andropogon gerardi) and Switch grass (Panicum virgatum) play host to different species belonging to this family of butterflies that comprises approximately 1/3 of all North American butterfly species. Inland sea oats (Chasmanthium latifolium) is a native commonly used in landscaping that also hosts multiple species of these stout, small winged, fast flying butterflies.
There are several flowering natives, readily available for landscaping, that serve as host plants for butterfly species.
Tecoma stans and Black Dalea (Dalea frutescens) provide homes for the larvae of the Dogface butterfly.
The popular Cenzio (Leucophyllum frutescens) plays host to the larvae of the Theona checkerspot and the ubiquitous Lantana sp. offers
nursery sites for the Painted lady larvae.
There are climbers that are favored by particular butterfly species Old man’s beard (Clematis drummondii) is dramatically covered with feathery achenes in the fall, sustaining birds with their seeds. In spring their leaves feed the larvae of the Fatal metalmark butterfly. The different species of passionflower vines are renowned for hosting a wide variety of butterfly species including many of the Fritillaries.
Finally it would be remiss if we did not mention the special relationship that the most famous of Texas butterflies, the endangered Monarch, has with the milkweeds . The toxins in the sap of the milkweed family are processed by the larvae making them toxic as well. This poisonous state is carried through metamorphosis into adulthood making them distasteful to birds that might prey on them.
Texas’ position at the base of the North American continent, places it in a position where it is the funnel that many migrating species (such as butterflies and birds) pass through. Thus, we have the delight of the aerial show of butterflies that pass through in Spring and Fall, as we as those that brave the hot summer and vagaries of winter. With a little forethought and planning we can be good hosts, planting species that provide sustenance for the young and old as well as shelter from wind, sun and rain.
Do you have any novel ideas for providing for wildlife in general, or butterflies in particular? Perhaps not just in residential landscapes but larger scale areas associated with business or local parks?
Noreen Damude and Kelly Conrad Bender (1999). Texas Wildscapes: Gardening for Wildlife. Texas Parks and Wildlife Press.
Jim P Brock and Kenn Kaufman. (2003). Field Guide to Butterflies of North America. Houghton Mifflin Company.