Roger Sorensen provides a series of development photos of a moth. I’ve indented his words:
I hope your readers won’t get too “squirmish” with these. If you’re interested, I can provide a Monarch report as the two I’m rearing (photos below) grow. It takes about 3 weeks to reach adulthood.I maintain a patch of various milkweeds in my pollinator garden and every year have Monarchs (Danaus plexippus) on them. This year though seems to be a banner year for another milkweed grazer, the Milkweed tussock moth (Euchaetes egle). I think these are good examples of Müllerian mimicry, which Wikipedia describes as “…two or more well-defended species, often foul-tasting and that share common predators, have come to mimic each other’s honest warning signals, to their mutual benefit.” The Tussock and the Monarch share the black-white-yellow coloration.Here’s a cluster of early instar tussock moth caterpillars on the underside of a Common milkweed (Asclepias syriaca). They can rapidly skeletonize leaves or even whole plants.
Here’s the same leaf 2 days later and the colony on another nearby leaf. Note how much the caterpillars have grown. They’re also starting to get “tussocky.”
Here’s a whole plant that was consumed by a caterpillar colony – and with a few Oleander aphids (Aphis nerii), a common pest of milkweeds – and also showing aposematic coloration.
Here’s a later instar of the caterpillar (at left) after having molted. This happens among leaf litter on the ground.
Here’s the caterpillar of milkweeds most are familiar with, though perhaps not when so small. I usually find a few eggs during the summer to rear indoors and right now I have two “kids.” The one of the left hatched on 7 August and is now a few millimeters long. The egg on the right looks to be recently laid but should hatch within a few days. Close-up photos follow of the hatchling and egg. The leaves are presently in a plastic food storage container with the petioles wrapped in wet paper towels. Once they grow larger I’ll move them to a rearing cage.