Found this caterpillar on milkweed while looking for Monarch eggs. It has continued eating the monarch leaves I supply. The location is Abilene, TX.
That is a monarch caterpillar. It is darker than most, but that happens occasionally.
Since you were looking for monarch eggs, do you rear a lot of monarchs?
If you are rearing the caterpillar, then you know to rinse off the milkweed leaves when you bring them in for the caterpillar to feed on…this keeps any potential viruses from infecting the caterpillar. It is good to keep the caterpillar in a clear jar or plastic drinking cup with a paper towel ‘lid’. That way you can view the progress of the caterpillar as it grows. And then it has the paper towel to attach to when it pupates. Your caterpillar will soon be a butterfly and be headed to the overwintering location in Mexico.
The monarch migration is well on its way to Mexico from the Midwest. My last caterpillars pupated by 9/22. We have a naturalist that is certified to tag the butterflies, so I dropped the last 3 chrysalis’ and last instar caterpillar to her to tag when the butterflies emerged.
The butterflies that migrate to Mexico this fall are the ones that overwinter and then head back northward in the spring. When it is warm enough, those butterflies head north laying eggs (perhaps in your area)…producing then next generation to continue northward next summer.
May this fall migration of monarchs have a good population that survives the winter and improves the total numbers.
Thanks for taking care of the monarchs.