We can learn much about butterfly gardening by examining the life history of some specific butterflies. More details on caterpillar host plants of common butterflies found, for instance, in Minnesota are given in Table 2 . Their larvae accumulate toxins from the host in their body and these chemicals can be found in the adult butterfly as well. Caterpillars and adults are strikingly colored as a way to advertise their toxicity and distastefulness to birds.
Some butterflies have only one generation a year.
The pupa overwinters and the butterfly emerges in the spring. Mourning Cloaks are the first butterflies seen in the spring, feeding on nectar from shrubs such as Amelanchier . Their caterpillars feed on a variety of common trees, such as willows, poplars and elm. They overwinter in barns, tree holes or other protected areas. Painted ladies are attracted to open areas with low vegetation and a variety of flowers.