Skip to main content
Entomology 2021 Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Presentation Icons
In-Person
In-Person
Livestream
Livestream
On-Demand
On-Demand
Student Competition
Student Competition
Video Chat
Video Chat
Ticketed Event
Ticketed Event
Poster Icons
Student Competition
Student Competition
In-Person
In-Person
Poster
Poster
On-Demand
On-Demand
Back
Video Q&A ViewAttendees 2

Medical, Urban, and Veterinary Entomology

Section Symposium

Opportunity, Constraint, or Mishap? Exploring Forces of Selection Acting on Parasitic Arthropods On-Demand Presentations

Geographic variation in phenotypes of Ixodes scapularis, the blacklegged tick, and impacts on current and future Lyme disease risk

On-Demand
On-Demand
In the United States, the blacklegged tick (=deer tick) (Ixodes scapularis) is responsible for the majority of vector-borne disease. The blacklegged tick is widely distributed across the eastern US, but the distributions of cases of diseases it causes are restricted to the northern part of its range.  Many factors vary over the geographical range of the tick, including climate, vegetation, vertebrate hosts, landscape and land use, and tick genetics.  Thus, it is not surprising that phenotypic variation of traits might arise throughout the tick’s range, but how might such variation be related to the latitudinal gradient of I. scapularis-borne diseases?  Here we focus on variation of one trait – the host-seeking behavior of the nymph, the epidemiologically most important life stage.  We present data from common garden experiments with laboratory-reared nymphs originating from 15 locations throughout the range of I. scapularis that support the hypothesis that southern nymphs tend not to quest above the leaf litter and how that is related to lower Lyme disease incidence.  We briefly explore two factors that might select for the “less risky” questing phenotype in the South: finding refuge from a greater risk of mortality from desiccation and increased likelihood of feeding on a preferred host, Plestiodon spp. skinks.  Understanding factors that might influence tick questing behavior is important for predicting future risk of I. scapularis-borne disease, because northern ticks are expanding southwards and warming climates may make some northern regions more like the current South.