Category: moths (Page 25 of 30)

Bug of the Week: Sunflower Moth Caterpillar

Before revealing the mystery insect from last week, let’s take a look at the clues again.

The patch of silk implies either Lepidoptera or Hymenoptera, the two orders of insect that produce silk (I have already ruled out spiders, which also make silk). The presence of bits of waste products, called “frass” in insects, indicates a caterpillar, because bees, wasps and ants don’t produce frass in the larval form.

With that in mind, I opened one of the flowers.

Yes, there is a small, stripy caterpillar. I believe it is the larva of the sunflower moth, Homoeosoma electellum.

You can see the moth and a better view of the caterpillar in this report of the sunflower moth in safflowers.

So, did you guess caterpillar?

Next week I have photographs of some very cool insects we see only in July here in Arizona.

Bug of the Week: Life Cycle of a Moth

It is easy to find photographs of butterfly life cycles because butterflies are bright, colorful and active during the day. People like them.

Moths, on the other hand, are commonly drab, secretive and fly mostly at night, so not as much is available.

This is what the typical adult moth looks like.

Some moths can be quite colorful, however, so color is not the only factor to consider. Another feature of moths is that their bodies are often thicker than that of butterflies, and the thorax area in particular may be covered with hair-like scales (illustration from Wikimedia). Therefore, moths look fuzzy.

The adult moths lay eggs. The size and shape will depend on the species of moth. These are silkworm eggs.

The yellow eggs on the leaf above were laid by an Io moth, Automeris io (Photograph by Gary Foster at Wikimedia).

The eggs hatch into larvae, commonly called caterpillars.

The caterpillar shown here is a type of cutworm. Moth larvae are essentially just like butterfly larvae.

Moth pupae, however, are quite different from butterfly pupae. Often moth larvae construct a bag made of silk, called a cocoon, and then pupate inside it. The pupa itself is plain reddish-brown.

Other moth larvae excavate underground chambers and pupate in the soil.

Butterfly pupae, in contrast, are called chrysalids and sometimes form colorful and elaborate shapes. They are often found attached to plants.

For another view of a moth life cycle, try this post about silkworms.

Although moths are often ignored, they are on the order of ten times more numerous than butterflies. That means that for every butterfly you see flitting about your yard, there may be ten species of moths hidden away. Something to think about…

Bug of the Week: Cutworm

My son found this in the soil.

A caterpillar that curls into a “C”-shape when disturbed is probably a “c”utworm. Cutworm larvae tend to overwinter in the soil as caterpillars (larvae).

Although it is not very pretty, you can see the suckers of the prolegs. Prolegs are the fleshy, leglike appendages found on the abdomen of caterpillars.

This caterpillar will come out of the soil to feed on new seedlings in the spring. Once it is full grown, it will pupate and then turn into a drab grayish-brown moth. You probably won’t see the moth because it flies at night.

Once it uncurls, the caterpillar gallops off to safety.

See you in the spring.

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