Yesterday, Chris, the plant curator at the arboretum, alerted me to the presence of some queen caterpillars in the Mojave Desert collection. I elected not to venture out in the nearly constant drizzle yesterday, but this morning, under merely threatening skies, I went to see them.


This is the plant they were on. A nearly leafless desert milkweed called Rush Milkweed. These gangly, stemmy plants don't look like they'd be very inviting to many insects, but I have found the opposite to be true. All summer, I have seen wasps, aphids, ladybugs, syrphid flies, milkweed bugs, and scale insects. Oh, and the occasional monarch caterpillar, because it is a milkweed after all, and now the queens, because they eat milkweed also. The caterpillars eat the flowers, young pods, stems, and the few skinny leaves that these plants make.

Since they are in the same family as the monarch, the queen caterpillars look similar, but there is a difference in their striping, and most notably, they have an extra pair of antennae about one-third the way down their back.




I have seen the queen butterflies only seldom at the arboretum. The only picture I have is this blurry one from 2003, but it's enough to see the similarities and differences between this and the monarch