Skip to content

The 9th annual National Moth Week is coming up July 18-26, 2020, so let's take a peek at the abundance of moths in our yard right now.

First there were the genista caterpillars (previous post).


This genista caterpillar was on a neighbor's Texas mountain laurel so I gave it a home.

It made a loose silk cocoon on the cloth at the top of the container and pupated. The orange-brown crescent shape looks like a typical moth pupa.

Perhaps we'll have a moth to show in the next few weeks.

We found at least two separate species of caterpillar on our desert fern tree. The green looper was the larger of the two.

It pupated in the bottom of its container.  Pupae from the family Geometridae often show some emerald green coloration in the thorax region.

Here's the adult. I'm not entirely sure what the species is, but it is common right now.

This is probably another of the same species I found sitting on a wall a few days later.

Moths can be hard to photograph, first of all because they hide in the shadows during the day and secondly because they fly away when someone approaches them.

This powdery gray moth was unusual because it was feeding on a milkweed flower during the day.

Notice the curious fold in the forewing?

You can see the curved fold even in the open wings.

The examples above are just the tip of the moth iceberg.

Let's keep an eye out for moths over the coming weeks and try to learn more about them. For activity suggestions and information, visit the National Moth Week website.

Looking for children's books about moths? Then check out Jerry Pallotta's gorgeous new Not a Butterfly Alphabet Book: It's About Time Moths Had Their Own Book!, illustrated by Shennen Bersani,

plus others on our growing list of children's books about moths and butterflies at Science Books for Kids.

A few weeks ago a friend and I visited the Desert Botanical Garden. As we passed by a Texas Mountain laurel plant, I noticed a caterpillar.

Okay, maybe I knew where to look.

A couple of other people came by, and saw that my friend and I were peering into the bush. I was struck by how different their reactions were.

A young boy spotted one and exclaimed, "Look, a caterpillar!" Soon he had found one after another, excited at each one, pointing them out to us.

A man --probably his father-- came up and said, "A pest."

They walked on.

Obviously, each of us has a unique perspective. For example, I knew the insects were called genista caterpillars, Uresiphita reversalis, and when they finished development they would turn into a moth. I've seen genista caterpillars every year in the spring on Texas mountain laurel plants for over a decade. The caterpillars feed while the plant is flowering, then disappear--pupate and overwinter as a pupa -- until the following year (see a photograph of an adult and a pupa). Generally the plant recovers after the caterpillars pupate, so no need to do anything about them.

Also, Texas mountain laurel leaves and bright red seeds are full of some noxious chemicals (toxic alkaloids). It is actually pretty amazing that the caterpillars can eat the leaves and survive. Genista caterpillars use the plant's chemicals to defend themselves, like monarch caterpillars use the toxins in milkweeds to defend themselves. They are specialized to those plants.

Even though everything seems to be changing (the garden is now closed), there's always hope that we can expect to see genista caterpillars again next year.

Have you ever seen a genista caterpillar?

You can count on seeing certain insects year after year.

genista1

An example is the insect that caused the webbing on this Texas Mountain Laurel. Can you spot it?

genista2

Here's a closer view. This photo has two insects in it.

genista3

This is the genista caterpillar. Once it completes the pupal stage, it will turn into a small brown moth (Family Pyralidae).

How do you think the moth finds the Texas Mountain Laurel plant?