July 31st, 2013
Except for spiders, no other critter gives people the heebie jeebies more than ticks. Ticks are well known bloodsucking external parasites of humans, pets, livestock and wild animals. They are also vectors of a wide variety of disease-causing organisms to animals and are second only to mosquitoes in terms of public health importance.
Ticks are wingless and possess a single, oval body region that is relatively flat (except when filled with blood). Adults and nymphs have eight legs; larvae have only six legs.
The most common ticks in our area are:
Blacklegged (Deer) Tick: These are widely distributed throughout the upper Midwestern U.S. They transmit Lyme disease among other types of diseases. The greatest risk of being bitten is in the spring, summer and fall.
American Dog (Wood) Tick: East of the Rocky Mountains. This tick can transmit Tularemia and Rock Mountain Spotted Fever. The highest risk of being bitten is spring and summer.
Lone Star Tick: This tick can be found in the southeastern and eastern U.S. However, they are now being found in the upper Midwest as well.
Where Are Ticks Found?
Ticks are found in habitats that support large numbers of vertebrate hosts such as mammals and ground-dwelling birds. Some of the most productive habitats are moist woodlands and areas of vegetation around the edge of forests, along forest trails and in grassy fields. Additional habitats include areas surrounding power line routes made through forests, in and around campgrounds, and in abandoned grassy yards in urban areas. Ticks also are found in tall grass associated with interstate rest areas where pets are allowed to walk.
How Do Ticks Find a Host?
Being flightless, ticks “wait” for us or our pets to walk by. They detect carbon dioxide, host odors, vibrations, and warm, moist air currents. Tick larvae usually remain on the ground, where they encounter small animals such as rabbits, rats and mice. Adult ticks commonly climb up vegetation, from which they grasp a passing host. They can often be seen at the tops of grass blades or on lower leaves of bushes engaging in “questing.” Questing is a behavior in which the tick reaches upward with waving front legs ahead of an approaching host. Adult ticks tend to feed on larger hosts such as deer, livestock, dogs and humans.
As it begins to feed, a tick secretes saliva containing compounds that increase blood flow, prevent clotting and suppress the host’s immune response. Ticks imbibe the blood that pools in the wound. At the same time, they regurgitate excess water that has been extracted from the blood meal into the wound. This process increases the possibility for the transmission of pathogens from a tick to its animal host. Transmission of a pathogen typically does not occur until an infected tick has attached and fed for at least 24 hours, which is why early detection and removal is so important.
The safest and most effective way to remove an attached tick is to grasp it behind the mouthparts with forceps and pull gently and steadily until the tick releases its hold. Pulling too strongly or twisting while attempting to remove a tick may result in tearing of the tick, leaving the mouthpart embedded in the skin. This can lead to bacterial infection in the feeding wound and, potentially, to the risk of contamination of the feeding wound by tick body fluids that may harbor pathogens.
Do not attempt to remove an attached tick with caustic chemicals or by applying heat. This can kill the tick before it disengages its mouthparts. It can also cause the tick to regurgitate into the feeding wound and, therefore, increase the chance of transmitting a pathogen.
The best way to prevent tick bites is to avoid certain habitats during the peak of tick season. If you do need to enter an area that is a likely or confirmed tick habitat, wear light-colored clothing, including a long-sleeved shirt tucked into pants and long-legged pants tucked into socks. This will not only help to prevent ticks from reaching your body, it will also enable you to spot any adult ticks on your clothing.
Apply a repellent containing DEET, and consider treating clothing with permethrin, which initially repels and eventually kills ticks that contact clothing. As soon as possible after an outing in tick habitat, remove clothing and conduct a thorough check of your body. Male and female adult ticks can wander on a host for up to several hours before they attach. This is why a thorough body check, paying particular attention to areas such as the head, underarm, and groin, can discover adult ticks before they begin to feed.
For More Information:
There are numerous sites that provide information on tick biology and control. The following sites are recommended as accurate and current sources of information.
Centers for Disease Control and Prevention www.cdc.gov
Tick Encounter www.tickencounter.org
Illinois Department of Public Health www.idph.state.il.us
Wisconsin Department of Entomology http://labs.russell.wisc.edu/wisconsin-ticks
Shane McCoy is an Associate Certified Entomologist with 17 years of experience in Pest Management and is the Technical Training Director for Wil-Kil Pest Control servicing the Upper Midwest. To learn more about Wil-Kil, visit http://www.wil-kil.com/ or contact your local office at 800-236-8735. Follow Wil-Kil on Facebook and Twitter (@WilKilPest).