Les Jones

Science > Name That Caterpillar

Ellie May Melissa found another critter. This is a caterpillar she photographed in the flower beds. Click on the picture for a higher-resolution image.

Those yellow and black warnings stripes almost certainly mean this caterpillar is poisonous to birds. Warning colors - such as the black and orange of the monarch butterfly - in invertebrates announce to predators that the potential prey is poisonous. Poisonous, incidentally, means toxic when eaten. Venomous means capable of injecting toxins. Monarchs don't manufacture toxins. In their caterpillar stage they eat milkweed and other toxic plants to which they are immune and store those toxins in their body tissues.

Caterpillars, like butterflies, try to confuse predators about the location of their head and tail, using eyespots, or - in this case - antennae-like appendages at both ends. In this picture, the head is on the left. You can tell by the presence of true feet on the left. The leg-like appendates on the right are pseudopods.

This was an easy identification. The picture in the field guide looked identical to the one Melissa took. Know what it is? Post your answer in comments.