You never know what you might discover by looking at a plant. For example, while I was waiting for someone I looked at a shrub in front of a store. I saw signs of caterpillars, so I looked closer.
It turns out it wasn't the small green caterpillar I was expecting. The one I was expecting has a black head capsule. This one has a light-colored head capsule.
Let's look closer.
The tubes are called trachea and they originate at the round openings in the caterpillar's sides called spiracles. We usually can't see the trachea because the exoskeletons of most insects contain pigments that block our view.
This see-through caterpillar probably turns into a pyralid moth. With some luck, we'll find out what kind in the next few weeks.