I found two monarch caterpillars in their 4th and 5th instars on Friday. I placed each one in its own netted cage and fed them both milkweed from by backyard; they both seemed to be doing well Saturday, crawling around and munching heartily. By Sunday morning, the 5th instar cat seemed lethargic and kind of confused as he was crawling around, with green stains on the mesh on the side of the cage. Around noon, he started doing the writhing back and forth motion on the bottom of his enclosure and then curled up in a C and twitched intermittently for about a day before I decided to euthanize him. On Sunday, the smaller cat was still going strong, but upon waking Monday morning, we found him in the same position as the other cat, essentially lifeless other than intermittent twitching, also with green stains on the bottom of his cage. I had cleaned their cages daily and changed the leaves (washed and dried thoroughly) daily, and the cats came from two separate locations in my town, so I doubted it was a similar parasite or disease. After much research on their symptoms, I began to fear that I had fed them tainted milkweed, although to my knowledge the plant in my backyard has never been sprayed with pesticides, and it did not appear to have melt or any fungus present. There are a couple of townhome units with HOAs that spray weed killer and such, but I thought my plant would be safe behind a privacy fence and over 50 yards away!! I was pretty heartbroken to think that I had ended their lives.
Last night I was out walking around and discovered another cat in about the late 4th to 5th instar. I decided to give the adventure of rearing a cat one more try. Most of the leaves where I acquired the cat looked pretty rough, and not in very good shape, except for some younger plants. I tried to take the biggest leaves I could, but he is refusing to eat them. I can try to go to another location this evening for older leaves, but I am afraid of what condition the cat will be in if he cannot eat for a whole day (especially after two days of near constant rain). Therefore, my questions are thus: how long can a cat go without food before it causes him detriment? Also, what exactly constitutes what is a leaf "in good condition"? I am afraid I am being too picky in choosing leaves, and now I am paranoid about giving toxic leaves to them. Can you direct me to pictures of leaves to avoid due to melt or OE spores or such? Finally, I have read posts on feeding calabeza and yellow squash. Would yellow squash be a good substitue food? Also, now that regular pumpkins are abundant, could the cat be fed a pumpkin pie pumpkin or regular carving pumpklin, or must it be the special mexican kind? Thank you for your time!!