As an Amazon Associate, GrowJourney earns from qualifying purchases. Read more: terms of service.
Have you ever cursed the bean leafrollers munching on your bean plant’s leaves? Have you ever marveled at the beauty of long-tailed skippers (Urbanus proteus) butterflies?
If so, you might be surprised to know that they’re actually the same thing! That’s right: bean leafrollers are the larvae of one of the most beautiful butterflies in the eastern United States: long-tailed skippers.
What is a skipper?
Skippers are a family of butterflies (Hesperiidae) that aren’t quite a moth and aren’t quite a butterfly.
Skippers are active during the day, but their small powerful wings give them different flight patterns than butterflies. Butterflies tend to glide and float slowly and gracefully, whereas skippers dart about quickly and jerkily, appearing like a small butterfly on a caffeine overload.
Skippers also have hooked antennae tips whereas butterflies have straight, slightly bulbous antennae tips.
Long-tailed skipper: pest or pollinator or both?
It’s important to remember that the categories we assign to nature don’t necessarily mean that nature has to fit neatly into those categories. For instance, many predators also become prey; pest insects almost always serve essential and important roles in their particular ecosystems.
In the case of long-tailed skippers, the damage they do to bean plants is typically so insignificant that they almost don’t deserve to be called “pests” at all. But they are certainly wonderful pollinators to have in your garden.
We should also say that in addition to your bean plants, long-tail skipper larvae also enjoy eating other plants in the legume family such as highly invasive kudzu and wisteria.
Identifying long-tail skipper caterpillars
If you’ve ever seen leaves on your bean plants with sections cut and folded over to create a pocket, then you’ve seen the work of long-tail skipper larvae/caterpillars, aka bean leafrollers. Inside that protected pocket, the caterpillar munches away.
Another key characteristic of the larvae is they have comically enormous eyes.
Their protective leaf pockets start very small, corresponding to the instar stage of the caterpillar inside. First instar bean leafrollers make tiny cuts and leaf pockets. By the fifth instar stage when the caterpillar is almost ready to pupate, entire bean leaves may be folded in half.
So why don’t we consider these bean leafrollers to be serious pests to bean plants?
First, the majority of the caterpillars are eaten by predators or even killed by diseases before they’re able to do much leaf damage. This is especially true if your growing methods encourage lots of predators to call your garden or farm home.
Second, even those lucky few caterpillars who make it all the way to pupa-hood don’t tend to seriously harm your plants or inhibit bean pod production.
So if you happen to see bean leafrollers on your bean plants, please just monitor them with curiosity and appreciation, rather than spraying them poison or squishing them. Another option is to simply remove them by hand and place them on a nearby wisteria or kudzu plant.
Identifying long-tail skippers
Long-tail skippers are quite easy to identify since they’re coloring and wing shape are so unique. (Both male and female long-tail skippers look nearly identical.)
Key differentiating features of long-tail skippers:
- vibrant blue coloring on the top of their wings,
- long wing “tails” extending from the base of their hind wings,
- characteristic hooked antennae tips (common in skippers versus butterflies).
We hope this article helps you easily identify and appreciate long-tail skippers and bean leafrollers at each stage in their lifecycle! We hope you welcome these pests to your summer garden and appreciate the extraordinarily beautiful pollinators they become.