I’ve been reading a bit lately about butterflies and how to attract them to your yard and garden. It’s important to plant flowers whose nectar attract butterflies, but don’t forget the larvae (caterpillars). Many butterfly (and moth) caterpillars only eat specific plants. The best known example is the monarch butterfly caterpillar, which eats only the sap from Asclepias species, or milkweeds, including butterfly weed (A. tuberosa) and swamp milkweed (A. incarnata).
(Author’s note: At this point let me acknowledge that it is a cheap ploy on my part to publish butterfly photos with this post. I should be posting caterpillar photos, but really….who wants to see those.)
There are many other examples:
The only host plant for larvae of the the Zebra swallowtail (above) is the pawpaw (Asimina triloba)–another great reason to plant this native fruit tree. Larvae of the gulf fritillary larvae (right) subsist exclusively on Passiflora species, known as passionflower or maypop. Alfalfa butterfly caterpillars (also known as orange sulphur) subsist only on, well, alfalfa (Medicago sativa).
Eastern black swallowtail caterpillars feed on members of the carrot family, primarily Queen Anne’s Lace that grows in the wild, but also including carrots, parsley, dill, and fennel. All caterpillars in the Speyeria family, which includes the regal fritillary, feast only on plants in the Viola species (violets). Scarlet runner beans (Phaseolus coccineus) feed gray hairstreak caterpillars, and Dutchman’s pipes (Aristolochia) are the only food eaten by the appropriately named pipevine swallowtail.
And as if I need any more reasons to love asters (Aster spp), they are the only food source for larvae of the aster checkerspot butterfly.
It perhaps should be said that if your goal is to attract larvae by planting these plants…you have to be prepared for them to be eaten. Share and share alike is rule #1 of the wildlife garden, after all.
OK, OK, in the interest of fairness, here is a monarch caterpillar.
And here is a gulf fritillary caterpillar on a passionflower:
All photos courtesy of Wikipedia, except the passionflower, which is courtesy of the Santa Rosa County, Florida Extension Center.