Pinee, Did you look up the Harvester Caterpillar? There is an awesome Photojournal on the Harvester linked to NABA. I'd find it really incredible if it is a Harvester. Harvesters usually eat woolly aphids found on Alder trees. Do you have an Alder tree around? I am totally fascinated by the Harvester BF. I saw my first one this spring at the nature park near my house. I've been reading up on them and trying to find the Alder tree in the park. So far, no luck. In the Photojournal, the author shows the life cycle of the Harvester. So you can see photos of the caterpillar. They are so, so fascinating. Could it be a Lady bug larva? They kind of look like slugs to me. They also eat the aphids. I'm inclined to think that what you have on your milkweed is an insect larva and not a BF. But, I've been known to be wrong! Sandy Here is a link that might be useful: Harvester Photojournal

Wow, fantastic photos. I've often wondered what these little guys look like; now I have an excellent reference. I agree, Sherry, they do look like the pull toys for dogs! :-) I've read these little cats can decimate wild milkweed. I often wonder if they are another reason the little wild 'Red Ring' milkweed is having such a time surviving in the wild. Mary

I have a shocking confession....I'm a tussock killer! They completely RAVAGE the milkweed and there's none left for the monarchs. This year I removed one tussock covered leaf from the common milkweed. Later in the season I found an egg-covered tropical milkweed leaf and the little terrors were just starting to hatch. I did an internet search to determine that they were tussocks since I'd never seen the eggs before. However, when I came back the next day ALL the eggs and cats had been devoured by either bees, wasps, or spiders. I'm guessing wasps since they really like the tropical milkweed flowers. Tussocks are like little milkweed piranhas. Long live the Monarchs! :)

How fun! The internet is filled with tons of informative articles about monarch cats -- here's one that gives a nice overview. Even if you don't plan on raising them indoors, you can get a general sense of the cat's/butterfly's life cycle (particularly starting at the paragraph after Pic #5). Just before a cat goes through each (of its five instar -- molt and grow -- phases), it'll generally lie quite still -- sometimes for hours. If there is plenty of food around, in my experience, cats will reach ~ 2" after its fifth instar -- right before it J-loops and turns into a chrysalis. All of my cats (in the yard) will often crawl as far as 40' (across the yard) from the milkweed plant to find a place to chrysalis. Watch where you step, and be careful reaching for pots (they love to hang from pot rims/edges), etc. No telling where they'll end up. 1- How do I know if a bigger caterpillar is still eating if he's not moving much? I don't want to disturb them if they're getting ready to go into chrysalis. Unless you plan on bringing it indoors, I would just leave it alone. There must be something built in biologically that if it sits undisturbed for a certain amount of time, it must be a safe enough place to J-loop and form the chrysalis.