Researcher attracts ticks on purpose
Thursday, April 30, 2015 2:00 AM
News
Pittsburg, KS
Most folks in the Four-State region go to great lengths to repel ticks and other summer pests. Ali Hroobi works even harder to attract them.
Hroobi, a graduate student at Pittsburg State University, has been doing research on ticks in southeast Kansas and, it turns out, this is a pretty good place to find them.
Hroobi, who came to PSU from Saudi Arabia, began his research on ticks under the direction of David Gordon, an associate professor of entomology in PSU’s Department of Biology.
Gordon said there is currently a high interest in tick research because of the diseases they carry that can infect humans. According to the CDC, ticks can transmit more than a dozen pathogens that can cause human disease, including Lyme Disease, Tularemia and Ehrlichiosis.
Beginning last summer, Gordon helped Hroobi develop a new cost-effective method of collecting ticks in order to determine their prevalence in southeast Kansas and what pathogens the ticks are carrying. Hroobi’s data is part of a larger study overseen by Ram K. Raghavan, an assistant professor in Kansas State University’s College of Veterinary Medicine.
“I was surprised at the density of ticks in this area,” Hroobi said.
Gordon said that the previous method of sampling was too labor intensive and costly.
“The standard method of sampling ticks is to drag,” Gordon said. “A drag is a three by three-foot piece of white flannel with a chain at the bottom and you just drag it over the brush. Two people carry it and you stop and you pick all the ticks off. You get covered with ticks and it takes an hour to collect a sample.”
Gordon wanted to find a way to attract ticks to a central location where they could be easily collected, so he turned to CO2 traps that use dry ice to generate carbon dioxide that attracts the ticks. Gordon said CO2 traps previously devised were either expensive or difficult to work with.
To come up with practical alternatives, Gordon relied on childhood lessons.
“My dad was a fixit man. He did everything,” Gordon said. “I learned a lot from him.”
Gordon designed a trap made from inexpensive PVC pipe, a piece of wood, a plastic container from the delicatessen and a piece of carpet padding for insulation.
“For $2 to $3 we could make these traps,” Gordon said. “We put them out and it worked! That’s the best part.”
Hroobi set the traps in three residential locations near Pittsburg between May and August last year. In each location, he divided the traps between grassy areas and forest.
“We wanted to look at grass and forest,” Gordon said, “and places where houses are and where deer come into the yard.”
The ticks found the traps irresistible.
“The C02 was quite attractive and ticks began moving towards the traps soon after they were baited,” Hroobi wrote in a poster presentation of his work. “As many as 100 ticks were on the trap container, the wood block or surrounding soil and vegetation the following morning. Ticks surrounding the traps were quickly gathered, dropped into the quart container that was sealed and stored on ice before processing in the lab. Within a two-hour period, large numbers of ticks were easily collected from 60 locations. This sampling technique generated sample sizes that are large enough to enable statistical comparisons of habitat preferences, windows of activity and other ecological and behavioral characteristics of ticks.”
In his study, Hroobi found the Lone Star Tick to be the most common tick at the sites he sampled by an overwhelming margin. The American Dog Tick or Wood Tick was next and the Deer Tick or Blacklegged Tick was a distant third.
He also found the most ticks to be in the forest, not the grass.
Gordon said Hroobi’s research needs to be followed up with additional studies to get a clearer picture of tick diversity and distribution over a wider region. Hroobi’s research and others like it are important, he said, because understanding the tick biodiversity in the region, the distribution of the species and their habitat preferences is basic to assessing the human risks for acquiring tick-borne illnesses and developing strategies for preventing those illnesses.
Since he conducted his early research, Hroobi has continued to work with Raghavan at KSU and he expects to begin a Ph.D. program there this fall.
Gordon said Hroobi’s experience is an example of the way that student research not only helps students learn and grow in their discipline, but also has the potential to offer meaningful contributions to broader research efforts that may affect the health and well being of people around the world.
For more on ticks and tick-borne diseases, visit this CDC website.
For more on the PSU Department of Biology.
