Victory for the Vectors? Climatic stress decreases tick survival but increases host-seeking behavior
Presentation Type
Poster
Keywords
ticks, acarology, climate change, disease
Department
Biology
Abstract
Ticks are vectors of many diseases including Rocky Mountain Spotted Fever and Lyme Disease, and they are expanding in geographic distribution. However, it is unknown how ticks will fare in rapidly changing environments due to climate change. Therefore, we used a novel method to simulate climate stress on individual ticks of three species - the lone star tick, the American dog tick, and the deer tick - to evaluate their survival, physiology, and behavior. Specifically, we placed ticks in two temperature ranges (15-250C and 25-350C) and three relative humidity treatments (32% RH, 58% RH, and 84% RH). We assessed the ticks daily for survivorship and frequency of questing, which is when a tick is perched with its front legs outstretched to latch on to a host. We measured water loss by comparing the mass of each tick when it died to when it was fully hydrated. We discovered significant differences in survivorship among humidity treatments for all three species. Ticks of all three species consistently died at approximately 30% water loss and were more likely to quest shortly before their death. These results demonstrate that climatic stress increases tick mortality but also increases tick questing. Further investigations of ticks’ behavioral and physiological responses to abiotic stress are necessary to develop robust models of how climate change will affect transmission of tick-borne diseases.
Faculty Mentor
Javier D. Monzon
Funding Source or Research Program
Academic Year Undergraduate Research Initiative, Summer Undergraduate Research in Biology
Location
Waves Cafeteria
Start Date
25-3-2022 2:00 PM
End Date
25-3-2022 3:00 PM
Victory for the Vectors? Climatic stress decreases tick survival but increases host-seeking behavior
Waves Cafeteria
Ticks are vectors of many diseases including Rocky Mountain Spotted Fever and Lyme Disease, and they are expanding in geographic distribution. However, it is unknown how ticks will fare in rapidly changing environments due to climate change. Therefore, we used a novel method to simulate climate stress on individual ticks of three species - the lone star tick, the American dog tick, and the deer tick - to evaluate their survival, physiology, and behavior. Specifically, we placed ticks in two temperature ranges (15-250C and 25-350C) and three relative humidity treatments (32% RH, 58% RH, and 84% RH). We assessed the ticks daily for survivorship and frequency of questing, which is when a tick is perched with its front legs outstretched to latch on to a host. We measured water loss by comparing the mass of each tick when it died to when it was fully hydrated. We discovered significant differences in survivorship among humidity treatments for all three species. Ticks of all three species consistently died at approximately 30% water loss and were more likely to quest shortly before their death. These results demonstrate that climatic stress increases tick mortality but also increases tick questing. Further investigations of ticks’ behavioral and physiological responses to abiotic stress are necessary to develop robust models of how climate change will affect transmission of tick-borne diseases.