Vacationers on Martha's Vineyard and Nantucket may have an ally in their attempt to avoid Lyme disease next summer -- a tiny wasp the size of this i.

The Massachusetts Food and Agriculture Department plans to release between 20,000 and 50,000 of the wasps on the islands off Cape Cod, where Lyme disease is rampant, in an attempt to control the deer tick that transmits the disease. The wasps are natural parasites of ticks.

Female wasps of the species Hunterellus hookeri like to lay their eggs in the larvae of hard-shelled ticks, such as wood ticks and deer ticks. Deer tick larvae feed on small mammals such as mice before becoming big enough to feed on deer. When the eggs hatch, the larval wasps feed on the larval ticks, eventually killing them.

"The hope is that if we repeatedly release {large numbers of} this wasp, it will knock down the overall tick population, thereby reducing disease transmission," said Dennis LaPointe, a technician working on the project.

Lyme disease is caused by a species of bacteria that lives in blood. People get the disease when they are bitten by a tick that has fed on the blood of an infected mammal. The tick bite may be hard to detect, but as the disease develops it can cause fatigue, arthritis, headaches, and, less commonly, heart problems, meningitis and other chronic neurologic problems. Between 5,000 and 8,000 cases of Lyme disease are reported in the United States each year.