Date: 03/29/2017

Number: 9

Do Caterpillars Drink?


We had a tiny bit of rain Tuesday night, so it was cool, and early Wednesday morning I cut 5-6 milkweed stems to take to the nine caterpillars I’m raising. I had to wade through the dewy roadside plants to get to the wild plants. I put them in a plastic bag to refrigerate later and quickly put two of the stems in my lettuce box that houses the monarchs.

Then having nothing better to do I sat with the box just in front of my nose observing closely the six caterpillars. I had been feeding them from a bag of oenotheroides stems that had been in the fridge for quite a few days and were drying out. All the caterpillars were “asleep” or inactive, but within moments moved to the fresh stems. Some remained inert, but three caterpillars move out onto the bottoms of the new leaves and, starting at the base of the stems, began a left/right, left/right rapid head and body motion across the bottom surface of the leaves.

They all appeared to be “drinking” or clearing the dew from the bottom of the leaves. One of the caterpillars at the third instar stage, when he’d finished the bottom sweep of the leaf out to the tip, went back to the base of the stem and “flagged” it by nibbling half way through the stem at the bottom side of the base, then he moved back out to the tip and began to feed. It took no more than half an hour to eat the entire leaf.

Eagle Pass, TX

Latitude: 28.7 Longitude: -100.5

Observed by: Carol
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