In recent weeks I've had a couple of contacts from Missourians asking what has happened to all of the butterflies this year. They weren't seeing the usual number on their properties. Then I heard from a coworker who has begun establishing a prairie planting on a former fescue pasture. She said that she is seeing more butterflies, other insects and birds on her property this year than she has ever seen before. The greater diversity of grasses and wildflowers on her place is attracting and producing more insects and the animals up the food chain that rely on them.
Many butterflies and moths thrive in sunny, open areas with a diversity of flowering plants. Natural habitats in Missouri that meet that description include prairies, glades and fens. A pasture of virtually a single species of non-native grass, while it will be sunny and open, will not supply the needs of most insects. The same can be said of most urban lawns, unless insect-friendly plants are included in nearby plantings.
Some butterflies require particular plant species as a larval (caterpillar) food source. A monarch butterfly will lay its eggs on a milkweed plant because the milkweed's leaves are what the monarch caterpillar eats exclusively. While most butterflies are not as particular about which flowers they visit for nectar, areas with more flowering plants can sustain larger numbers of butterflies.
It is always difficult to say why one person is not seeing the wildlife to which they are accustomed, when others are reporting good numbers. But it is a safe bet that by establishing a diverse landscape with plentiful native plants, you can maximize your chances of attracting the butterflies and other native wildlife that you wish to see.