Developments to Watch
THIS PARASITE TAKES A BITE OUT OF TICKS
Tiny parasitic wasps, about the size of a pin head, may help reduce the spread of Lyme disease by curbing the population of deer ticks in the heavily infested Northeast. Researchers from the University of Massachusetts at Amherst released chalcid wasps on Martha's Vineyard and Nantucket last summer by exposing tick-bearing mice to the little buggers. The wasps, which attack only ticks, reproduce by laying their eggs inside tick larvae or nymphs. When the eggs hatch, the wasp offspring eat their host before it can reproduce. Ticks collected on the islands this summer indicate that the wasps have established themselves in their new locations.
UMass entomologist Roy Van Driesche estimates that the wasps could reduce the deer-tick population from New Jersey to Maine by as much as 30%. But "this will not eliminate deer ticks," he warns. "It is a partial biological-control mechanism." Anywhere from 15% to 30% of deer ticks--which feast on the blood of deer, mice, and other mammals--are believed to be carriers of Lyme disease. Left untreated, the malady can lead to arthritis and heart problems.EDITED BY NAOMI FREUNDLICH