Ticks can be serious pests in and around homes and can transmit numerous pathogens that cause disease in humans and animals. In the United States, both ticks and tick-borne diseases have been on the rise over the last 20 years. Cooperation between both homeowners and pest management companies is essential in managing ticks on properties.
TICK BIOLOGY AND DISEASE
All tick species have four different life stages: egg, larva, nymph and adult. The larvae of ticks are 6-legged and often referred to as seed ticks. Except for eggs, each life stage must have a blood meal to survive. The tick lifecycle may take up to three years to complete from egg to adult. Some tick species will choose different hosts for each life stage, while other species will feed on a single host to complete their life cycle. Several tick species have a three-host life cycle where the larvae, nymphs and adults each feed on a different host. Feeding typically lasts a few days. Ticks spend most of their time off the host within the environment, either molting or seeking out their next host.
Ticks feed exclusively on blood and must feed on an animal to survive, develop and reproduce. A single female, depending on the species, will lay a batch of eggs ranging from 1,000 to 18,000 eggs and then will die. Ticks can be a nuisance, causing irritation from their bites and even paralysis, but the most serious problem with ticks is the diseases they can spread to humans, pets and livestock. The pathogens that ticks can transmit while feeding include protozoans, viruses and bacteria.
Ticks find their host through a process called questing. The tick will move to the tip of a blade of grass, or cling to other vegetation using their back legs with their front legs stretched outwards to grab onto a host. Ticks detect a host using body odors, carbon dioxide, body heat, moisture, vibrations and even by shadows. Once a host comes near, their questing becomes more rapid as they move their front legs, seeking host attachment. However, some tick species, i.e. A. americanum, are considered hunter ticks and will walk or crawl rapidly for meters in search of a host. These ticks do not have to wait around for a host and tend to distribute further distances.
In 2017, United States health departments reported record numbers of human tickborne disease to the Centers for Disease Control and Prevention (CDC), an increase of over 10,700 cases from the previous year (48,610 in 2016 compared to 59,349 cases in 2017). The most prevalent tickborne disease in the United States is Lyme disease, followed by anaplasmosis/ehrlichiosis, then Rocky Mountain spotted fever. Lyme disease is caused by the bacterium Borrelia burgdorferi and is transmitted by two tick species: the black legged tick and the western blacklegged tick. When present, symptoms localized to the bite site occur within a few days to weeks and then other symptoms (fever, rash, facial paralysis and arthritis) may occur months to years following a bite. A localized rash may occur shortly after the bite with a characteristic bulls-eye pattern appearance. Ehrlichiosis is caused by a group of several bacteria that invade white blood cells. Symptoms of ehrlichiosis in humans include fever, headache, muscle pain, nausea, vomiting and restlessness. The symptoms occur within 5-10 days of a tick bite. Rocky Mountain spotted fever is caused by the bacterium Rickettsia rickettsii. Symptoms typically occur within nine days after a tick bite and may include a rash, fever, headache and muscle pain.
PERSONAL PROTECTION FOR CLIENTS AND TECHNICIANS
Personal protection should be communicated to customers as a part of any tick management program and be a first line of defense from ticks and disease. Education is key in helping customers understand how to protect themselves and can also build trust leading to a great working relationship between the customer and pest control company. The recommendations for customers below should also be followed by pest control technicians working regularly outside who may be potentially exposed to ticks.
Encourage the use of repellents for ticks when customers are outdoors but only recommend repellents that are EPA registered and proven to work. The CDC recommends repellent products with the active ingredients DEET, picaridin, IR3535 and/or oil of lemon eucalyptus. When applying a repellent, special attention should be paid to shoes, socks and the bottom of pants legs where ticks would most likely attach. Permethrin-treated clothing can also help to prevent ticks from biting. If a customer wishes to use a permethrin spray, it should only be applied to clothing and not directly to the skin. Allow the clothing to dry before wearing and spray in an open, ventilated area. Always read and follow label instructions when applying any repellent.
When outside, also wear protective clothing that covers arms and legs. Wear light colored clothing to more easily see ticks and tuck pants into socks to prevent them from climbing underneath clothing. If a customer or their family has been outdoors, especially in wooded or grassy areas, encourage them to do a full body check on themselves for ticks when returning inside. Tick checks of persons and animals should occur each time when coming indoors after being outside. If a tick is present on the body, remove it immediately.
If a tick does become attached, it takes approximately 36-48 hours for the transmission of the bacteria that causes Lyme disease. Less time is required for the transmission of other pathogens. For instance, the transmission of the agent of ehrlichiosis can occur within 24 hours. Therefore, the earlier that removal happens, the better. Tweezers should be used for tick removal using slow, steady pressure, pulling straight up and as close to the skin as possible, so that the entire tick and mouthparts are likely to be removed.
Pets can also be a source of ticks, especially if the customer has pets that live indoors but spend a lot of their time outdoors. Ticks may bite a pet and alternatively hang onto the fur and drop off when the pet comes indoors. Brown dog ticks can live for weeks or months inside a home without food or water after they have dropped off. Other kinds of ticks have been reported surviving several days indoors in humidity above 65%. Tick prevention should be used on pets after customers consult with a veterinarian on recommended products for tick control. Vacuums can be used on pet items indoors as well as outdoors. Communication with the customer by the pest management professional should be conducted to encourage laundering and drying of pet items on high heat to kill all life stages of ticks.
INTEGRATED PEST MANAGEMENT STRATEGIES
Standard tick management practices should be implemented to prevent and treat for ticks. Landscape management around structures can go a long way in providing a tick free zone near buildings, but applications of pesticides may be necessary to provide full protection.
Landscape management can provide substantial tick control for a customer and should be implemented as part of an integrated pest management strategy around buildings. There is a strong correlation between landscape features and tick abundance. High risk areas for ticks include the perimeter area around yards with dense vegetation, wooded lots and the unmaintained areas between the yard and forested areas. Limiting suitable environments for ticks and wildlife that may carry ticks is highly effective for tick management.
There are several practices customers can implement to reduce tick populations around a structure:
- Keep bushes trimmed and grass cut low around the house to minimize tick habitats around the yard.
- Reduce vegetation in the lawn and keep areas open to sunlight.
- Rake or blow leaf litter and plant debris from areas that are highly traveled by people.
- Introduce hardscape (patios, decks, paths) into the landscape to reduce vegetation and areas that could harbor ticks.
- Restrict use of groundcover only to areas where people do not frequent.
- Keep play areas (swing sets, playgrounds) away from woodland areas and in sunlit areas if possible.
The use of insecticides, or if for ticks specifically, acaricides, is still an extremely effective means of tick control when combined with habitat modification practices. Early applications of chemicals—in May or June—will help target developing nymphs, while fall applications would be more targeted for the control of adult ticks. Targeted applications of insecticides to the “tick-zone” should be performed in areas where ticks are most likely, such as lawn and woodland edges and perimeter areas where foliage is less maintained. The use of both liquid and granular insecticides is encouraged. All products should be used per the label after evaluating the habitat and tick conducive conditions. Liquid insecticides can be applied with backpack misters or hydraulic sprayers. Focus treatments where ticks would be expected, typically no higher than three feet above the ground. Granular insecticides can be beneficial in areas where leaf litter and organic matter are abundant to penetrate deeper into areas where ticks could be harboring. Consider “raking-in” the treatment where areas of mulch or leaf litter are particularly thick to ensure penetration of the granules.
Consider the following guidance regarding the use of chemicals by pest control applicators:
- Only use products registered for the site in which the product will be used and specifically labeled for tick control.
- Appropriate licensing and certification for outdoor tick control should be attained by the pest control firm prior to treatment.
- Only treat areas that are conducive to tick habitats:
- Areas where the lawn meets woods, stone walls and some ornamental plantings.
- Spray several yards into woodlands where tick density is highest.
- Spray perimeters of the yards where people frequent (pathways, gardens, mailboxes) but not on play areas or edible plants.
- Sufficient spray volume and pressure should be used to thoroughly cover and penetrate vegetation and leaf litter where ticks may be hiding.
- Treatment is usually not necessary and not effective in open, sunny lawns.
- Do not directly spray the flowering parts of plants to prevent harming visiting pollinators.
- Do not surface spray any insecticides onto impervious surfaces.
- Information on the service agreement or ticket should include the name of the pesticide product being used, the active ingredient in the product and the amount of product applied.
- Always read and follow pesticide label instructions.
Wildlife around a home can harbor ticks and present a challenge for tick control. A wildlife management program can be implemented with tick control to reduce rodents and other wildlife. Alternatively, chemical treatments that specifically target wildlife can also be used to kill ticks that are feeding on wildlife. Tick tubes that contain a cotton material treated with a pesticide can be used to kill ticks on small nest-building rodents. When the rodents use the cotton material for nesting or it comes into contact with the rodent’s fur, the ticks become exposed to the chemical and die.
If using tick tubes, consider:
- Placing tubes twice a year.
- Place tubes every 10 yards in places that mice and other rodents frequent (flower beds, bushes, woodpiles, stone walls and sheds).
- Replace tubes that are empty.
- If the tubes aren’t being touched in an area, move them to another area that is getting rodent activity.
- Always read and follow label instructions.
Another rodent targeted method available is bait boxes. These systems use non-toxic rodent bait to attract mice and chipmunks. When the rodent feeds inside the box it is exposed to a cotton wick treated with a pesticide commonly used for topical pest applications. When the rodents leave the bait box, attached ticks will become treated and will die with some added protection from future ticks. Tick control boxes should be placed in the “tick zone” in shaded areas where rodents frequent and conditions are conducive to tick activity. The boxes should be placed according to label instructions—typically, 30 feet apart and approximately 10 boxes should be used per one-half to one acre of land.
Tick Infestations Indoors
While rare, it is possible for infestations of ticks to occur inside of a home. There is only one species of tick, the brown dog tick, that can complete its entire life cycle indoors. Unlike other ticks, the brown dog tick doesn’t have high moisture requirements and can live in drier indoor conditions. Indoor infestations of ticks typically begin from a pet that has brought in a few ticks, particularly a pregnant female tick, with the infestation going largely unnoticed until the ticks are larger and more numerous.
Once the tick species has been correctly identified, integrated pest management strategies should be implemented indoors to ensure control and elimination of the infestation. If concerned about ticks, customers with indoor and outdoor pets should consider using a tick preventative prescribed by a veterinarian. Kennels should be washed and treated with a disinfectant or an appropriate pesticide. Blankets, dog bedding and other fabrics that are infested should be washed and dried on high heat to kill all life stages of ticks. A vacuum can be used in areas where ticks are harboring, including baseboards, walls and other cracks and crevices. The structure can then be treated with a product labeled for tick control in areas specified by the label including treating bedding or pet materials. Again, do not apply any pesticides to these items unless the label permits it. These products should never be directly applied to a pet. In addition to treating indoors, habitat modification and targeted insecticide applications outdoors as described above should be performed to help prevent future indoor infestations.