Tick Management

Overview

Ticks are obligate blood sucking ectoparasites (external parasites) that require an animal host to survive and reproduce. Depending on the species, several ticks may have different hosts of warm-blooded creatures, such as humans, mammals, birds, reptiles, and amphibians. There are about 867 species of ticks distributed worldwide, 80 USA species and 13 Minnesota species.

People react differently to tick bites. Typical bites normally trigger skin irritation, which is itchy. However, in animal farms, severe infestations on animals can cause anemia, weight loss, and even death from the consumption of large quantities of blood. Besides itching, a few species of ticks (not more than 10%) are vectors of a large range of disease-causing pathogens of domestic animals and humans.

In North America, the pathogens associated with the following diseases can be transmitted by tick bites: Lyme disease, human granulocytic and monocytic ehrlichiosis, babesiosis, relapsing fever, Rocky Mountain spotted fever, Colorado tick fever, tularemia, Query fever, and tick paralysis.

Three species of ticks are likely to be encountered by people: black-legged (deer) tick, American dog ticks, and brown dog ticks. There are three major disease-causing organisms are transmitted through the bite of an infected deer tick. These are Lyme disease, human anaplasmosis, and babesiosis. The American dog tick is responsible for transmitting Rickettsia rickettsii, which causes Rocky Mountain spotted fever in humans. This tick can also transmit tularemia. Brown dog ticks are not known to transmit diseases to humans, but may transmit disease among dogs.

To avoid tick bites, it is important to be prepared before it is too late. Like mosquito and other insects, the onset of the tick's season is temperature dependent issue, the warmer the spring temperature, the faster insect pests can develop. Therefore, if you live in known tick infested areas, watch the weather and be prepared for these bloodsuckers. Usually, adults of deer ticks (the most common Lyme Disease tick vectors) can emerge in patchy snow at temperature of 40°F and more.

Identification

Ticks are not insects, but are arthropods more closely related to mites, spiders and scorpions. There are two groups of ticks: the "hard" ticks and "soft" ticks. The major morphological differences between the two groups that hard ticks (Family Ixodidae) have a hard shield just behind the mouthparts as well as the mouthparts are readily visible from above. Whereas, soft ticks (Family Argasidae) do not have the hard shield and mouthparts are not readily visible from above. Tick larvae have six legs (sometimes called seed tick), while nymphs and adults have eight legs.

Black-legged (Deer) Tick

Adult deer tick females are red- brown in color with black shield near the head. They are less than 1/8 inch long. Males are darker and smaller than females. Larvae and nymphs are much smaller and paler in color.

American Dog Tick

American dog ticks are the largest of the eastern wood ticks, and among the most common tick found in Minnesota. A female American dog tick is brown to reddish-brown in color with gray or silver markings on the upper front part of the body, while the male has the markings on the enter body. Males are about 1/8 inch long, and the fully engorged females will get about 1/2 inch after a blood meal.

Brown Dog Tick

Brown dog ticks are about 1/8 inch long and red-brown in color with no markings. After feeding, an engorged female is ½-inch long.

Biology

Ticks have four different developmental stages: egg, larva, nymph and adult. All life stages require a blood meal for development. Depending upon the tick species, ticks may have one-host life cycle (all stages staying and feeding on only one animal host before the female drops off), or multi-host lifecycles (ticks have a different host animal at each stage of their life). One-host ticks may have more than one generation per year, while the life cycle of multi-host ticks may be completed in one, two or three years.

Deer Tick Life Cycle

Deer ticks have two-year life cycle: In year 1, eggs hatch in spring into larvae, which feed once and molt into nymphs. Nymphs become dormant for the winter. In year 2, nymphs feed from May through July. In the fall, nymphs molt into adults. The females feed on deer and other large mammals, mate, lay eggs, and die. If females don't feed in the fall, they try to find a large mammal host in the following spring. Male black-legged ticks attach to a host to wait for females, but do not take a blood meal.

American Dog Tick Life Cycle

The life cycle of American dog tick requires three different hosts and requires about two months to complete, but can take up to two years depending on the host availability, host location and the temperature. Following mating, females feed for five to 14 days to repletion. Fully engorged females drop themselves into the ground and lay 4,000 to 6,500 eggs within four to 10 days. Males usually die after mating, while females die after they lay their eggs. Eggs hatch in 26 to 40 days depending on the temperature. Larvae attach to small mammals, such as mice and feed on blood for two to 14 days and then drop to the ground to digest their blood meal and molt into the nymphs within a week or more. Nymphs attach to a larger host, such as skunk, raccoon, etc. Upon attachment, they feed for three to 10 days before they drop to the ground to digest the blood and develop into an adult. This usually takes from three to several months depending on temperature conditions. Adults then will attach to wandering dog or larger mammals as available. Mating occurs on the host and the life cycle repeats itself.

Brown Dog Tick Life Cycle

The adult female tick feeds on a dog's blood, engorges, and then drops off the host to deposit a mass of 1000-5000 eggs. These eggs are usually found in cracks and crevices around dog's sleeping and wandering areas. The eggs hatch in 19-60 days. The larvae attach to dogs when they are available and feed for 3-6 days, become fully engorged with blood, and then drop to the floor. After dropping from the host, larvae hide for 6-23 days before molting into nymphs. The nymphs attach to dogs, drop off, and molt to an adult in 12-29 days. Similarly, adults seek a blood meal from dogs and repeat the life cycle.

Habits

Mating behavior: For most ticks, mating occurs on the host, as the male tick also requires a blood meal. However, since male deer ticks do not need to feed prior to mating, mating of this species may occur on or off the host.

Feeding behavior: Ticks feed solely on blood of warm-blooded creatures, including humans. Females feed slowly, remaining on the host for several to many days; when they are fully engorged with blood, they drop off the host to lay eggs and die. Male ticks feed occasionally, take small blood meals, and may remain on a host for weeks before dying. Hungry (unfed ticks) can stay for a long time without food under unfavorable environmental conditions, such as low temperatures, or when hosts are not available in winter. For example, American dog tick larvae, nymphs, and adults can survive up to 11 months, six months and two years without feeding, respectively; however, they would quickly feed on suitable hosts when available.

Habitats: Most ticks usually hide in grassy areas and in areas where fields/lawns meet wooded areas. They also found near foundations of buildings, in crevices of siding, or beneath the porch waiting for suitable hosts. Conversely, brown dog ticks are indoor problems; they do not breed in the woods or in open places. This species can be found indoors hiding behind baseboards, window casings, window curtains, bookcases, inside upholstered furniture, and under edges of rugs.

Host finding and attachment behavior: Ticks use several cues to locate their hosts. These include carbon dioxide, ammonia, lactic acid, and other specific body odors as well as body heat, moisture, vibrations, and visual signs, such as a shadow. In order to increase the chance of coming into contact with a suitable host, ticks exhibit a questing behavior. A questing tick usually climbs up a blade of grass, vegetation, structure, etc and then waits patiently with its front legs outspread. This position will enable the tick to grab a passing by host that brushes against its legs. Once on a host, a tick may attach quickly or crawl over the host for some time. Some ticks attach on certain areas like the ear or thin-skinned areas, while other species may attach almost anywhere on the host. Most species are three-host ticks; that is, each stage seeks special hosts, feeds, and then detaches before developing into the next stage. For example, American dog tick larvae typically seek small animal such as mice, while nymphs attack larger animals, such as raccoon, and adults attach to dogs or larger animals. Conversely, it has been known that the brown dog tick seldom attacks animals other than dogs. All life stages of the brown tick can found on dogs in the U.S.

Management

1. Tick Identification

Since some tick species could be disease vectors, it is very important to properly identify the tick species you are dealing with in case of future illness.

In addition, proper identification will reduce the risk of unnecessary treatment actions.

2. People And Pet Treatment

If you live in an area known as tick-infested area and can't control the way your pets wander outside, they will be constantly exposed to ticks. Consult with your veterinarians for direct pet treatment and recommendations.

3. Tick Repellents

Apply tick repellents on clothes and shoes before entering wooded areas or areas known with tick infestations. DEET and Duranon (0.5% permethrin) are commonly used tick repellents. Both products have pros and cons and possible human side effects; therefore, carefully follow label directions and use caution. Avoid treating sunburned, damaged skin and eyes with DEET, as it is usually applied directly to the skin and can be absorbed through the skin. On the other hand, Duranon is applied to clothing only and should not contact skin and eyes.

4. Habitat Modification and Host Exclusion

Habitat modification means making environments around a structure unfavorable to ticks and their natural hosts survival. This management method includes, but is not limited to, the following practices: Keep your lawn mowed regularly, thin vegetation near woodlands, along pathways, and areas where people and pet may come into contact with ticks, cut tall grass, trim back overhanging shrubs and trees, remove leaf litter and plant debris in wooded and landscaped areas, and remove woodpiles, fallen trees stumps, and any clutter which provide harborage for rodents.

The removal and exclusion of tick natural hosts, such as mice and rats in and around buildings is an important step of any tick management program. If not removed, they will serve as a reservoir of ticks and cause a treatment failure. Regularly seal all possible rodent entryways in and around a structure.

5. Pesticide Treatment

When pesticide applications are needed, communicate with your pest management professional (PMP) to apply a thorough treatment to all tick-infested areas.

If ticks were found indoors and a pesticide treatment is deemed necessary, your PMP will apply crack, crevice and spot treatments using an EPA approved residual product labeled for managing ticks to areas where ticks are known to be sighted or hiding. For heavy infestations or when egg masses of ticks (i.e., brown dog tick) hatch, space / Ultra-Low Volume (ULV) treatments can be applied to give a quick knockdown of tick population accompanied with applications of residual insecticides in cracks, crevices and spots where ticks are sighted. To manage ticks in outdoor areas, the PMP will carefully apply an EPA approved residual product to achieve a thorough coverage and penetration of the vegetation and leaf litter. Outdoor applications should target all tick's habitats and areas near tick "hot-spots" or along the "tick zone". Treating open fields and lawns is not necessary. Outdoor tick treatments should include, 1) areas where the lawn meets the woods, stonewalls, or ornamental plantings. 2) Several yards into bordering woodlands, 3) Groundcover vegetation like Pachysandra near the home or walkways, 4) Perimeter of areas used by people, such as play areas, gardens, outside storage areas, walkways paths to neighbors or mailboxes. Anyhow, general use commercially available pesticides for public are less effective, breakdown rapidly, and multiple applications may be required.

All pesticide applications should be done at the right time of year. For deer ticks, it is recommended to treat for ticks early May or early June targeting nymphs or on October targeting adults. For American dog ticks, treat anytime after the adults emerge in the spring. In heavily infested areas, especially where re-introduction of ticks are most likely to occur from surrounding areas by host animals, begin treating in the spring and continue treating until the frost at 2-4 week intervals targeting both adults and nymphs.

Similar to other pesticide applications, people and pets should be kept off treated surfaces until dry.

FAQ

Q. I live near a wooded area with many ticks around my house. Any recommendations for minimizing the risk of encountering the terrible ticks would be appreciated.
A. In the fall and early in the spring, call your PMP to apply an EPA approved pesticide around the perimeter of your house as well as to all tick habitats, especially where the lawn and wooded area meets. In addition, do the following recommendations:

• Always check you pets for the presence of ticks.
• Immediately remove ticks from pets and humans as soon as they are noticed. It is recommended that ticks should be grasped with tweezers at the point where their mouthparts enter the skin and pulled straight out with firm pressure.
• When entering tick-infested areas, keep clothing buttoned, shirts inside pants, and pants tucked inside boots.
• Do not sit on the ground or brush against any vegetation, especially in bushy areas.Use tick repellents, such as DEET or Duranon (0.5% permethrin) to lightly cover exposed skin and clothing. Read the product's label for instructions. Never apply repellents to cuts, wounds, or inflamed and irritated skin. Do not over treat (saturate) the skin or apply beneath clothing.
• It is important to treat your pets for ticks. There are a variety of commercially available products for you to use on your pets. Be extremely careful not to allow chemicals to get into the eyes, nose, or mouth of the pet. See your veterinarian for proper products and recommendations.