In a particular location, adults from the previous generation are active from March to July and then newly moulted from nymphs adults are active from September to December. The nymphs are active from May to November and they are the worst - smallest (~1 mm), most numerous and infectious. The larvae are active from July, when the hatch starts, until November - but they are no hazard, non-infectious until after their first meal of infected mouse blood (thank goodness, they're smallest ˝ mm, most numerous).
We anticipate an exceptional year for numerous adult and nymph ticks with high rates of infection due to high prevalence in their mouse hosts. We've already had at least four reportable cases of Lyme Disease in a population of <1000. The first association of Lyme Disease with Borrelia Burgdorferi was in Wisconsin in 1986.
I recommend Ecology and environmental management of Lyme disease, edited by Howard S. Ginsburg (Rutgers, 1993). Ginsburg is eminent. My first training was in medical entomology in 1967/8.
For tick eradication I recommend Tick Tubes by Daminix ($4/ea, $2.50/ea in 1000's). My outdoor work clothes are soaked with Permethrin.