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Tick, Tick, Tick Index


The University’s Tick Index was created and is maintained by Tom Daniels, Ph.D., of the Vector Ecology Laboratory. The index is an estimate of the risk in Westchester County of being bitten by a nymphal or adult deer tick, both of which are carriers of Lyme disease.

After several weeks of low risk, the index begins to climb again this weekend as the adult ticks emerge. There are three stages in the tick life cycle: larvae, nymph and adult. The nymphs peak in June and July and cause the largest number of Lyme disease infections because their greatest numbers coincide with increased activity of lightly dressed humans in the woods, and because the nymphs are much smaller than adults (about the size of a poppy seed) and so are harder to spot.

Adult ticks are active in the fall. Risk of infection from adult ticks will diminish and eventually fall to zero once average temperatures consistently fall below 40 degrees Fahrenheit. For this weekend’s index, go to:

The Vector Ecology Laboratory is housed at Fordham’s Louis Calder Center Biological Field Station in Armonk, N.Y.


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