Data from: A novel laboratory method to simulate climatic stress with successful application to experiments with medically relevant ticks

Ticks are the most important vectors of zoonotic disease-causing pathogens
in North America and Europe. Many tick species are expanding their
geographic range. Although correlational evidence suggests that climate
change is driving the range expansion of ticks, experimental evidence is
necessary to develop a mechanistic understanding of ticks’ response to a
range of climatic conditions. Previous experiments used simulated
microclimates, but these protocols require hazardous salts or expensive
laboratory equipment to manipulate humidity. We developed a novel, safe,
stable, convenient, and economical method to isolate individual ticks and
manipulate their microclimates. The protocol involves placing individual
ticks in plastic tubes, and placing six tubes along with a commercial
two-way humidity control pack in an airtight container. We successfully
used this method to investigate how humidity affects survival and
host-seeking (questing) behavior of three tick species: the lone star tick
(Amblyomma americanum), American dog tick (Dermacentor variabilis), and
black-legged tick (Ixodes scapularis). We placed 72 adult females of each
species individually into plastic tubes and separated them into three
experimental relative humidity (RH) treatments representing distinct
climates: 32% RH, 58% RH, and 84% RH. We assessed the survival and
questing behavior of each tick for 30 days. In all three species,
survivorship significantly declined in drier conditions. Questing height
was negatively associated with RH in Amblyomma, positively associated with
RH in Dermacentor, and not associated with RH in Ixodes. The frequency of
questing behavior increased significantly with drier conditions for
Dermacentor but not for Amblyomma or Ixodes. This report demonstrates an
effective method for assessing the viability and host-seeking behavior of
tick vectors of zoonotic diseases under different climatic conditions.