Selective Host Attachment byIxodes scapularis(Acari: Ixodidae): Tick–Lizard Associations in the Southeastern United States

Abstract

Questing behavior and host associations of immature blacklegged ticks, Ixodes scapularis Say, from the southeastern United States are known to differ from those in the north. To elucidate these relationships we describe host associations of larval and nymphal I. scapularis from 8 lizard species sampled from 5 sites in the southeastern U.S. Larvae and nymphs attached in greater numbers to larger lizards than to smaller lizards, with differential levels of attachment to different lizard species. Blacklegged ticks are generally attached to skinks of the genus Plestiodon in greater numbers per unit lizard weight than to anoles (Anolis) or fence lizards (Sceloporus). The broad-headed skink, Plestiodon laticeps (Schneider), was a particularly important host for immature I. scapularis in our study and in several previous studies of tick–host associations in the southeast. Blacklegged ticks show selective attachment to Plestiodon lizard hosts in the southeast, but whether this results from behavioral host preferences or from ecological factors such as timing or microhabitat distributions of tick questing and host activity remains to be determined.

Peromyscus leucopus,Mus musculus, and humans have distinct transcriptomic responses to larvalIxodes scapularisbites

“…Relatively little attention has been paid to how any vertebrate-including humans or rodents-interact with larval I. scapularis, though field studies have documented a strong association between larvae and P. leucopus in the northeastern and midwestern United States [21,[26][27][28], as well as birds and reptile hosts in the southeastern United States [21,29,30]. In his 1989 review, Ribeiro stated that their unpublished data demonstrated that larval I. scapularis can feed efficiently on the North American deermouse P. leucopus but not on C. porcellus [6].…”

Changes in the geographic distribution of the blacklegged tick, Ixodes scapularis, in the United States

“…This difference in questing behavior results in far greater risk of human bites by nymphs from northern populations, which is of direct public health importance as most human infections with I. scapularis -associated pathogens in the Northeast and Upper Midwest are considered to be associated with bites by nymphal rather than adult ticks (see Eisen and Eisen, 2016 ). Moreover, immatures of northern population I. scapularis more commonly feed on mammals serving as effective reservoirs for human disease agents, including Lyme disease spirochetes, compared to southern population immatures, which more frequently infest lizards ( Ginsberg et al, 2021 , 2022 ). Consequently, pathogen infection prevalence for questing nymphs and adults of I. scapularis is generally much higher for northern compared to southern population ticks ( Ginsberg et al, 2021 ; Lehane et al, 2021 ).…”