Animals: Ditches & Itches

Officials of Chicago’s suburban Des Plaines Valley Mosquito Abatement District know the difference between a mosquito drainage ditch and a hole in the ground. Furthermore, they prefer the hole. In a century-old pestilent swamp in Palos Park one afternoon last week they blasted out a vast sump, of which they planned to make a mosquito-proof “wildlife oasis.” If mosquito larvae in the abaters’ sump don’t watch out, the bladderwort plant will get them. If insectivorous plants don’t get them, whirligig beetles, back swimmers, dragonfly nymphs and top-water minnows will. Ditches get stagnant and mosquito-filled. It is hoped and expected that from Palos Park’s hole in the ground no single adult mosquito will fly—for which the valley’s residents may thank their itching stars, for a single female mosquito can beget in a single season 75 times as many bloodthirsty offspring as there are human beings to bite on the face of the earth.

All this was very important news to wildlife conservationists, 2.000 of whom—trout fishermen, farmers, Camp Fire Girls, scientists, sentimentalists—gathered in Baltimore last week for the third North American Wildlife Conference, welcomed news of the Des Plaines Valley experiment. Mosquito control was the subject of the conference’s bitterest debate. According to conservationists, drainage ditches of Eastern and Southern States, which end-to-end would belt the world almost 2½times, have dried away vegetation, starved wildlife. Said Audubon Societies’ William Vogt: “Intelligently conceived, expertly prosecuted, adequately maintained, and completely justified mosquito control is as rare as the Eskimo curlew.”