This is not the work of the elements

David M. Carroll, Swampwalker’s Journal, Boston, Houghton Mifflin, (1999), 2001, p. 4-5.

Scanning the drapings and carpetings of reed canary grass, I see a more deliberately designed structure, a carefully wrought casing nearly an inch and a half long, built from the same grassy materials in which it lies. This is not the work of the elements, a small insect larva. This house made of straw, fashioned from cut pieces of reed canary grass and sedge, adhered to an interior tube of spun silk, served a protection for a caddis fly larva. Until is metamorphosis into mothlike, winged adult, the larva had lived an entirely aquatic life, molting throught a series of five encasings like this, making a larger one each time as it grew. In what now seems to be a grassy upland field in which meadow grasshoppers, crickets, and katydids sing and fedd, an insect larva that can live only in water completed the subadult phases of its life.
Lifting a decaying section of alder stem that has become partially embedded in the turf of the basin floor, I find an even more readily recognizable indication of an aquatic environment, the shells of half a dozen tiny fingernail clams, ranging in size from an aighth to three-eights of an inch. The shells are huddled where the last of the season’s water collected as summer came on. Fingernail clams inhabit a wide variety of permanent wetland habitats, but they are also able to live in pools that dry up every year. Adults and young burrow into the substate during the dry season and emerge when their pools refill.
The casing of the larval caddis fly and the shells of the fingernail clams lie to close the base of a tussock of grasslike growth. A number of symmetrical mounds of inflated sedge have colonized a deeper pocket of the two-acre basin.