Monarch caterpillars molt (shed their skin) five times throughout their larval stage. The "skin" that is left behind is actually the caterpillar's exoskeleton. An insect's skeleton is on the outside, as opposed to on the instead like mammals, fish, reptiles, amphibians and birds. Endoskeletons provide support inside the body in the form of bones and cartilage, whereas As caterpillars grow, their exoskeleton gets too tight, so they need to shed it in order to continue to grow. Each molt results in a new "instar" stage. Therefore, when the egg hatches, that tiny 2 mm caterpillar is in its first instar stage.
It will molt three more times and grow exponentially over a couple of weeks. Each stage lasts 3-5 days. The fifth and final molt is when the fifth instar caterpillar becomes a chrysalis.

Our iOS Apps
Our iOS Apps
Knotweed!

Knotweed! familiarizes you (like it or not) with one of the world's 100 worst invasive plant species, Japanese knotweed. The other three knotweed species (including the hybrid) are also covered in-depth. The app provides photos and annotated identification slides throughout the seasons to educate users about this seemingly unstoppable plant. Included is a section on the devastating impacts of knotweed on your home (be sure to check out the image of it growing through the foundation of a home-yikes) and in the natural environment. The management section provides guidance on controlling it should you have the misfortune of finding it on your property, as well as Dos and Don'ts when dealing with these plants.