Ask Mr. Smarty Plants

"Certainly caterpillars of at least the native Battus philenor (Pipevine swallowtail) seem to prefer and/or survive better on some species rather than others.  We are hard put to find native Aristolochias around here, but people grow several tropical species including vines such as A. elegans, A. grandiflora, and more recently a sort of shade-tolerant ground-cover species, A. fimbriata, has hit the nursery trade.  The latter species is a great attractor of both pipevine swallowtails and polydamas swallowtails, which are as of the past few years equally common here.  Battus polydamas, Polydamas swallowtail is more of a tropical species that seems to have moved northwards to include Houston in its range.  Several people have told me that while B. polydamas caterpillars seem to be able to survive on some of the tropical viney Aristolochias, B. philenor caterpillars sicken and die on them. However, both butterflies do equally well on A. fimbriata.  I cannot speak to the palatability of native Aristolochias to either species, as they are not commonly grown here.

And, as far as fritillaries and Passifloras go, there are some species of Passiflora (e.g., P. vitifolia) that fritillary caterpillars will not eat/do not survive on.  In the case of P. vitifolia I always assumed it is because the leaves are quite tough as compared with the species the caterpillars do eat.  Dr. Larry Gilbert (Professor, Biological Sciences, University of Texas at Austin) could tell you that most Heliconius species eat a limited suite of the available Passifloras in a given habitat.  Certainly we cannot assume that the caterpillars of a given species of butterfly can eat every species in a given genus of plant.  Sometimes the specialization is more finely tuned than that."

Dr. Greig also said that she had spoken to Joshua, who is the enthusiastic and knowledgeable owner of Joshua's Native Plants and Antiques in Houston Heights.  He says that the Aristolochia species that is toxic to Battus philenor (the native pipevine swallowtail) is A. gigantea (Brazilian Dutchman's pipe), the species with the huge, purple-velevety flower.  However, Battus polydamas does fine on it.  According to him, other Aristolochia species including A. triloba, A. elegans, A. fimbriata, and A. tomentosa are palatable and safe for both Battus species.  He says that B. philenor females will occasionally lay eggs on A. gigantea, but the larvae sicken and die.

The native Aristolochia species that can be found in the general vicinity of Tyler and Smith County, Texas are:

Aristolochia reticulata (Texas dutchman's pipe)

Aristolochia serpentaria (Virginia snakeroot)

Aristolochia tomentosa (woolly dutchman's pipe)

Aristolochia tomentosa