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Have you guessed which picture is a caterpillar from the previous post on Butterflies Everywhere? The real caterpillar is the lowest photo. The photo above it is a bird-dropping sitting on a nearby leaf.

The caterpillar, sometimes called an orange dog, is thought to mimic bird-droppings to avoid being eaten by birds.

We are quite excited because this caterpillar turns into the beautiful giant swallowtail butterfly (photo at Butterflies of Southeastern Arizona website).

Another interesting thing about the orange dog caterpillar is that it has an unusual defense. When alarmed, it shoots out a smelly orange, horn-like structure called an osmeterium.

orange gog

This one is pretty small because the larva is still small. I found an even better shot of an orange dog osmeterium at the BugGuide website.

Not six feet away we have a pair of caterpillars on our desert milkweed. These are the larvae of the queen butterfly. They resemble monarch larvae, but have three sets of spiky appendages and the stripes are red rather than black.

queen caterpillar

I caught a picture of the adult queen butterfly as it was laying eggs a few days before on another desert milkweed.

queen butterfly

By the way, it is not an accident that we have so many caterpillars and butterflies in our yard. When we planted our landscape, we purposely chose plants that are food for caterpillars. Butterfly gardening is something that the whole family can enjoy. If you are interested in learning more, just let me know.

Good news, the Mexican yellow caterpillar from last week’s Bug of the Week made it to adulthood. I was able to find the chrysalis, which was empty because the butterfly had emerged. The chrysalis is the pale yellow object on the side of the twig. Way to go Mexican yellow!

meican yellow chrsalis

This week I spotted evidence of another caterpillar on our grapefruit tree. When you see a leaf with ratty edges like this, it can only be a few insects. I was pretty sure I knew which one. Sure enough, when I tipped the leaf over I found it.

damaged leaf

Which of the pictures below is the insect I found? I’ll tell you next week what it is and how it is doing.

guess1guess2

Not far from where I found the cellar spider last week, I found this caterpillar feeding on a small ironwood tree. Instead of being alarmed that a caterpillar was eating my plant, I was actually pretty excited. I was pretty sure it is the larval form of the Mexican yellow, a very pretty butterfly. If not, then it is a closely related species.

caterpillar

If you are interested, here is a link to the Butterflies of Southeastern Arizona page which shows what the caterpillar might turn into, the Mexican yellow, Eurema mexicanum.

And here is their picture of the larva stage. Do you think it is the same kind, too?

The caterpillar was over an inch long, probably nearly mature. The next day it was gone. Hopefully it crawled away to form a chrysalis in a protected place and I'll be showing you a photo in a few weeks.