Part of the problem surrounds the use of pesticides and fertilizers made up of chemicals in these parts of Iowa. Some of the problem is the mass destruction of weeds and wild flowers which attract butterflies, and which butterflies need to reproduce.
Two plants which form the ecological balance for butterfly populations are milkweed and Queen Anne's Lace, which provide nutrient for the Monarch and the Swallowtail butterflies.
Since I have lived in "these parts', I have not seen either plants in the ditches or along the edges of fields. Nor, have I seen those groups of butterflies.
Even some birds need so-called weeds, like coneflower, coreopsis, globe thistle, goldenrod, Joe pye weed, rudbeckia and many others.
We are killing wildlife by being too fussy and too efficient. BTW, there are several websites which give away free milkweed seeds.
When I had my own house in England, we planted a wildlife friendly garden on purpose. This was in 1989. We had plants which attracted butterflies, bees, and birds plus a hedgehog log pile in the
back of the garden.
More thought must be given to God's creatures and not just the greed of agribusiness.