A new friend off Reddit was nice enough to share some Imperial (Eacles imperialis) moth eggs with me last week (from Pennsylvania), so I decided to document their life cycle here, for others to enjoy. Raising giant silk moths is rewarding, but takes time and dedication, as well as a huge supply of host plant. I've been known to take cocoons as well as caterpillars on vacation more than once!
I've never raised this species before, though, so it's very exciting.. plus they are super funky caterpillars! I'll keep this updated as best I can, and please let me know if you ever have any questions. I like to think raising these and releasing them to the wild will help the population in some small way. We need more giant silk moths.. they are all gorgeous!
^ these creamy yellow eggs were deposited on July 16, 2025 and sent to me via mail, arriving on the 21st. Most giant silk moth eggs hatch in about 11 days (in my experience), but wiki says Imperial moths are 10 days to two weeks. We will see!
^ I keep the eggs in a container like this on a scrap of paper towel that is ever so slightly damp. I remove the lid several times a day to add fresh air, but mostly to check out the eggs! It's important to keep the eggs in a slightly moist environment.. you don't want visible moisture on the sides of the container, though.. that's too much. I also find that a container with a snug lid that's easy to remove it best, as you're going to be removing it a lot once they hatch.. you don't want a difficult lid that requires too much effort .. any false move and the eggs can go flying! DO NOT ADD LEAVES TO THE CONTAINER until the caterpillars hatch. Leaves can give off gases that will kill the eggs.
July 24, 2025 .. so 9 days after the eggs were deposited and I wake up to them being slightly darker and with tiny red lines appearing on the side of the eggs. Baby caterpillars forming inside!!
July 25, 2005 - day 10 - the eggs are noticeably darker today and have more definition. From other pictures I've seen, I should be able to make out the baby caterpillars within the egg prior to hatching. There is still one egg that's light yellow. I suspect it wasn't fertilized.