A caterpillar is the larval stage of butterflies and moths.Sulfur Pupa This stage usually lasts from about two weeks to a month, and is the longest life stage for many lepidoptera (butterflies and moths). During this stage, the caterpillar can grow in size more than 30,000 times.

Caterpillars have a segmented body consisting of a head, a thorax (with three pairs of jointed legs with hooks), and an abdomen (usually with five pairs of stumpy prolegs). Its primary function is to eat and grow in preparation for pupating.

Tiny Monarch Caterpillar
Immediately after hatching, the Monarch caterpillar is so small it can barely be seen. It grows very fast though, feeding on nothing but milkweed leaves. A monarch caterpillar sheds its skin five times during the larval (caterpillar) stage. In about 2 weeks it is about 2" long and full grown, ready to pupate.

A recent tragedy resulted in the untimely death of a number of my Monarch caterpillars. I bought several nice milkweed plants from a local "big box" store to feed the youngsters. Knowing that many commercial nurseries use pesticides to keep their plants insect free, I rinsed the plants six times before offering the leaves as food to the little ones. The next morning I was shocked to find a large number of the young monarch cats were dead. Monarch Caterpillars None of the other babies in the work room had been affected. The only explanation was the commercial milkweed still contained enough poison to kill them. This nearly broke my heart, as many of them were nearly ready to pupate. Doing a little research into this, I found that the pesticides used by commercial nurseries are quite long lasting. Several sources recommend hold milkweed for at least eight weeks, watering regularly, before using the leaves as food. I won't make this mistake again, and hope that my loss can be a lesson for others. Using milkweed from this source previously had never been a problem. However I can't trust them again. I am going to research the grower of the milkweed and try to talk to them about the problem. In the meantime I am also looking into trying to grow my own, but it grows slowly, at least in the beginning.

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