Tigers on the Loose in the Garden

By Greg Grant, Contributing Writer

Someone once asked me “When did you fall so in love with nature?” My immediate response was "The minute I opened my eyes.”

I can’t ever recall a time in my life when I wasn’t fascinated with every forest, field, flower, bird, bug or butterfly that I could hear, touch or see.

With “pollinators in peril” such a hot topic these days, I thought I’d share a bit about one of my favorite butterflies, the eastern tiger swallowtail.

First, I must make two confessions. The tiger swallowtail is actually my second favorite butterfly, but since it is more common in Texas than my favorite, we will tame tigers today. And I have to admit that swallowtail butterflies are the largest and showiest butterflies, so I’m guilty of admiring them over the smaller, less-flashy flappers. So be it. 

Sweet swallowtails

The swallowtail butterfly family contains up to 700 species in the world, mostly tropical. More than two dozen are found in North America, with seven found regularly in Texas. Swallowtail butterflies earned that name because of their long tails, reminiscent of the sleek and agile birds known as swallows.

The vertical black and yellow stripes on the tiger swallowtail make it unmatched in the butterfly world. The only one remotely similar is my beloved black-and-white zebra swallowtail, which does not venture farther west than the Piney Woods of East Texas. The eastern tiger swallowtail, on the other hand, is found as far west as I-35 in Texas.

I’m not alone in judging it a beauty since it’s considered the first North American butterfly to be portrayed in art. Sir Walter Raleigh’s third expedition commander, John White, painted it in 1587 on Roanoke Island in North Carolina.

There’s no way to distinguish black-and-yellow striped male-tiger swallowtails from females. However, the eastern tiger swallowtail periodically has an all-black female form that mimics the toxic pipevine swallowtail.

When the light shines through the undersides of her dark wings though, the even darker black stripes can be seen above the single row of orange spots. You have to be stealthy to observe this distinction, but I enjoy hunting for these camouflaged tigers. Unfortunately, like all swallowtails, eastern tigers beat their wings when nectaring, making photography and sometimes black-female identification tough.

Tiger swallowtails often nectar on azaleas, buttonbush, lantana, lilacs, narcissus, pentas, phlox, vitex and thistles. Remember that the next time you wonder why thistles exist.

Tiger swallowtails are common in both the wild and home gardens, but (like all butterflies) they can come in waves between absent periods. They are usually the first showy butterflies I see each spring. I can usually count on them nectaring on my ‘Grand Primo’ narcissus in late February or my lilacs in early March.

During the summertime they are especially fond of the ‘John Fanick’ and other heirloom standing phlox that I have collected through the years. They can generally be seen until November. Most folks aren’t aware of this fact, but like most butterflies, the swallowtail adults only live for a few fleeting weeks.

How host plants help

Nectar from flowers is important to all butterflies, but host plants for the larvae are equally as important. Without both, butterflies would cease to exist.

The most common larval host plants for tiger swallowtails are black cherry and ash trees. Remember that the next time you are bashing Arizona ash trees, as every native plant has a purpose.

The early young larvae of tiger swallowtails look just like bird droppings, a smart trick that keeps them safe from hungry birds. Mature larvae are green with big eyespots on their swollen thorax, another scare tactic for the birds.

After learning to identify all the swallowtails, my next chore is becoming proficient at learning their larvae. Gardeners need to get past the old way of thinking that all bugs, worms and caterpillars are bad. There are actually far more good guys than bad guys.

Landscaping for butterflies is similar to landscaping for birds. Host plants are crucial for raising larvae, while nectar plants are essential for viewing a wide array of native butterflies.

Swallowtail butterflies often sip water and dissolved minerals from mud and wet sand. This is known as “puddling.” If you are lucky, you might see a whole group of them “at the watering hole.”

As with all wildscaping, one of the most critical elements to success is avoiding widespread use of broad-spectrum insecticides. Nature intended for a constant crop of caterpillars to feed the birds, which in turn help protect the plants from complete defoliation, and then spread the seeds to make more plants.

It’s a beautiful cycle that’s worked efficiently for millions of years. Also, be very aware that the same insecticides that kill beetles and aphids kill butterfly larvae and adults as well.

Therefore, it’s crucial to grow plants that survive insect attacks and only treat those whose lives are threatened. I often use shears on pest-riddled plants instead of insecticide. Texas-tough plants are well known for immediately sprouting back with fine foliage and dodging the unsightly wave of pestilence.

Importance of identifying

As with birds, a camera and a good pair of binoculars help when learning to identify butterflies.

The pair I use for birds works just as well on butterflies. A good identification book is a must too. Much information is found on the Internet, although it’s not all accurate and much of it is for butterflies and plants in other areas of the country.

It’s best to rely on university websites and the experience and expertise of trained lepidopterists. You certainly don’t have to be a scientist or own a computer to enjoy tiger swallowtails, however.

Their annual awe-inspiring beauty is there for all to enjoy as long as we continue to provide habitat and sustenance for them.

Always remember that we are just one piece of the puzzle. If you haven’t already, transforming your landscape into a “pollinator garden” is a good start toward the worthy goal of sustainable stewardship.