On a sunny, cool day as fall gave way to winter, a team of biologists and technicians dragged white cloths through the underbrush at Lord Creek Farm in Lyme. They were looking for blacklegged ticks, which carry Lyme disease and four other deadly illnesses. As ticks attached to the cloth, the team counted them and put them in jars for further study at their lab at the Connecticut Agricultural Experiment Station in New Haven. Japanese barberry bushes grew thickly beneath the trees at this private horse farm that for years has cooperated with Lyme disease researchers. As the group dragged cloths, they noticed ticks on each other’s pant legs and coats, and began to pick them off.