A survey for nymphs of host-seeking Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) on tree trunks in deciduous forests.

Trunks of 83 trees in a mixed deciduous forests in Maryland were sampled for the presence of nymphs of the blacklegged tick, Ixodes scapularis Say, and the lone star tick, Amblyomma americanum (L.). Although one or more nymphs of either I. scapularis or A. americanum was found in leaf litter and substrate < or = 1 m from the bases of 47% of the trees sampled, a total of 6 I. scapularis nymphs was found on the trunks of only five trees. No nymphs were found on the trunks of 12 dead trees. No A. americanium nymphs were found on any tree trunks. The trunks were sampled to 2.5 m above the soil, but the nymphs were found < or = 1 m from the ground. More than 50% of I. scapularis nymphs found in the leaf litter < or = 1 m from bases of living trees were north of the trees sampled, whereas few I. scapularis were found west of trees. These findings suggest that the I. scapularis nymphs' presence on tree trunks is of little ecological consequence, unless nymphs were being removed from tree trunks by acquiring hosts at such a rapid rate that nymphal numbers on trunks could not accrue.