Houston is brimming is with butterflies this season! Moths, too.
After a dismal showing during last year’s prolonged drought with almost no butterflies at all, this year local butterflies have bounced back with a vengeance! Or maybe “vengeance” isn’t a word usually associated with butterflies. In any case, there are lots of them.
I have never seen so many butterflies in my backyard garden – both as babies (caterpillars) and adults. Pipevine swallowtails are particularly abundant right now, and I had dozens of monarchs a few weeks ago. I’ve seen black swallowtails and giant swallowtails, gulf fritillaries, and a few sulphurs as well. I just acquired three small sassafras trees, and they came complete with a couple of my favorite caterpillars: the spicebush swallowtail, which are the inspiration for the giant caterpillar sculpture at the Cockrell Butterfly Center entrance. And I’m not the only one who is seeing an abundance of butterflies; many Houston gardeners have made similar observations.
In addition to these garden species, I’ve noticed big numbers of some of the forest-inhabiting butterflies such as hackberry and tawny emperors, question marks, and red admirals. These butterflies typically visit sap flows or rotten fruit, and their caterpillars eat hackberry or elm leaves (or nettles, in the case of red admirals), so to see them you need to take a walk in the wood. I take my dogs walking at “Wortham Island,” a former oxbow bend of White Oak Bayou that is now an off-the-beaten-path wooded area in northwest Houston, and have seen clouds of emperors, lots of question marks, and a red admiral or two. Snout butterflies, another species more common in wooded areas, have appeared in my yard for the first time, sipping water off the sidewalk.
And a new butterfly species may be on the horizon! As we reported in the latest Museum News, a zebra swallowtail (Eurytides marcellus), until now unknown in Houston, was spotted laying eggs on paw paw plants at a local nursery. Hoping that this sighting might not be a complete accident, I’ve planted a couple of paw paws in my yard, and am keeping my eyes open and fingers crossed. Zebra swallowtails are fairly common in the Big Thicket area, less than 100 miles northeast of us. I’ve always said that if people from Cleveland, Texas to Houston would just plant paw paws, we could probably bring this gorgeous butterfly to our area!
On the down side, I have not seen any orange-barred sulphurs for a couple of years, and the polydamas swallowtails, which seemed to be overtaking the pipevine swallowtails, have also been less visible.I’m guessing that the cold winter of 2010-11 may have knocked back the populations of these tropical species, and they haven’t made it back in large numbers yet.
So why is this year so good for butterflies? I can only guess that the weather conditions have been just right this spring and early summer. We’ve had enough rain and lots of warm, sunny weather in between. Certainly all the interest in planting for butterflies can’t hurt. The only reason there are so many pipevine swallowtails and monarchs in my yard is because I’ve had dozens of their caterpillars eating all the Brazilian pipevine and Mexican milkweed I’ve planted. Providing host plants is vital. Of course, where I’m seeing the butterflies now is at the pentas and Mexican bauhinia that are blooming profusely these days, so nectar plants are important too!
On a different note – but still keeping with the lepidopteran theme – there is a wonderful new Peterson Field Guide available on moths of northeastern North America. Unfortunately it is NORTHeastern – but many of the species portrayed in the excellent illustrations do occur in our region. I highly recommend adding this book to your library. Moths may have more subtle coloration than butterflies, but many are quite spectacular mimics of lichen, bird droppings, leaves, or other insects. And although a few are pests of forest trees or in the garden, most are harmless and are important sources of food for bats (as adults) and songbirds (as caterpillars).
I was interested to read in the moth book introduction that there is a citizen science program on moth-watching in Great Britain. So little is known about our moth fauna here in the USA; it would be great if something similar could be launched here. Did you know that there are about 15 to 20 times as many moths as butterflies? In North America, there are about 11,500 moth species to 725 butterfly species. Perhaps with the availability of books like this one, people will start to pay more attention to these poorly known and poorly understood creatures. All it takes is leaving your porchlight on and observing (and trying to identify) the nocturnal creatures that are attracted to it. But be aware that some of the most colorful moths fly during the day.
Another useful thing to do where moths are concerned is to rear the caterpillars you find. Just because they don’t turn into beautiful butterflies does not mean they are not interesting in their own right! Do keep a record of the host plant the caterpillars eat.
Long live the Lepidoptera!