After raising a few generations of Monarch butterflies, we wanted to extend our butterfly rearing to other species. We noticed these pretty black and blue butterflies flying around our neighborhood and learned they were Pipevine swallowtail butterflies. The host plant is Pipevine. Baby caterpillars like to stay close together. (Strength in numbers!) Pipevine caterpillars are black with red spots. Their chrysalis hangs like a hammock and they can be green or brown (they can blend well against certain backgrounds). The boys have a beautiful blue hue on their hind wings while the girls are generally all black. Both have these pretty blue and orange markings on their backside.