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Fri September 6, 2013
Nature's Obligate Relationships
It is the height of monarch butterfly season in New Hampshire. Though fewer migrants have returned this year. They're producing the generation that will undertake one of the most impressive migrations: two-thousand miles to overwinter in Mexico.
Adult butterflies feed on the nectar of many different flowers but require very specific plants when laying their eggs. Eggs hatch into caterpillars that feed only on the leaves of particular species.
Monarch butterflies lay their eggs on milkweed, the one and only food for monarch caterpillars. Milkweed is what's known as an "obligate" host plant for monarchs. The species must have milkweed to reproduce. New Hampshire's state butterfly, the rare Karner blue, also has an obligate host plant: wild lupine. The great spangled fritillary, with a name that suggests its dramatic size and appearance, lays its eggs on or near violets, and the Milbert's tortoiseshell butterfly lays its eggs on stinging nettles.
The one-on-one obligate relationship underscores why a diversity of wild plants is important. "Out there," at the wild edges of backyards, along roadsides and the natural landscape beyond, many stories unfold, unknown and unheralded for the most part: plants and animals in relationship, connected to survive.
And there are untold stories of another kind, of people assisting these relationships, going a little wild themselves. One of my favorites is a longtime volunteer for New Hampshire Audubon.
Although ninety years old, Margot still mows her lawn, maneuvering around the occasional milkweed that appears for the monarchs. Other than a small patch of grass, her yard is quite wild: a real "pollinator's paradise."