Tick Population Plummets in Absence of Lizard Hosts

Researchers at the University of California, Berkeley, recently conducted a study to determine what the effect would be on juvenile Lyme infected ticks when their host, the Western fence lizard, was removed from their habitat. The Western fence lizard is known for its ability to reduce the threat of Lyme disease. The results of the study were quite surprising, not what the researchers had expected. One of the lead researchers Andrea Swei thought the removal of lizards would increase the risk of Lyme disease, which in turn, caused a decrease in the risk of Lyme disease in humans.

In an earlier study that was conducted in 1998, it was discovered that the Lyme infected ticks who fed on the Western fence lizard's blood were eradicated of the disease. The lizard's blood was actually killing the bacteria in ticks that caused Lyme disease. The Western fence lizards have been credited with the low levels of Lyme disease in many parts of the United States.

This recent study, conducted prior to the 2008 tick season, had researchers capturing and removing 447 lizards from 6 to 14 plots in two designated areas in California. The remaining 8 plots were used as control. For the next few months, researchers trapped other potential tick hosts, such as the woodrat and deer mouse, to see if they hosted more ticks than usual as a result of the removal of the lizards. Researchers discovered that 95% pf ticks who could not feed on the Western fence lizard's blood preferred no other host.

This study would suggest that the role of the lizards in reducing the risk of Lyme disease is quite significant, but it must be pointed out that the study focused on juvenile ticks only. What the results would be on adult ticks is uncertain but it is known that there is already a lower infection rate for adult ticks because of their earlier feasting on the lizard's blood. So what is the more effective way to reduce the threat of Lyme disease- remove the Western fence lizard's who are known for their ability to reduce infection in ticks or increase their population so there are more hosts for the ticks to feed on?


Source: http://www.sciencedaily.com/releases/2011/02/110215191631.htm