The tick…

As blood feeders, ticks can be a nuisance; their bites can cause irritation and, in the case of some ticks, paralysis. Ticks also can transmit several human and animal disease pathogens including Lyme disease, human babesiosis, ehrlichiosis, and Rocky Mountain spotted fever. In Connecticut, the two most common ticks are the blacklegged tick, Ixodes scapularis (formerly known as the deer tick, I. dammini) and the American dog tick, Dermacentor variabilis. Additional information is available from the Experiment Station fact sheets on Tick-Associated Diseases, Ticks, Tick Bite Prevention, and the American Dog Tick.

The blacklegged tick has four stages; egg, larva, nymph, and adult (male and female). Each active stage feeds only once and slowly; requiring several days to ingest the blood. All stages will feed on people and pets. Nymphs, from whom most people acquire Lyme disease, are active during late spring and summer. Therefore, most control efforts are targeted towards the nymphal stage. Adult I. scapularis are active in the fall, warm days of winter, and spring.

By contrast, only the adult stage of the American dog tick feeds on people and pets. These ticks are active from April through August. Manipulating tick hosts, the landscape, and the selective application of pesticides can reduce the abundance of ticks around the home.

Host reduction and exclusion . . .
The establishment of homes in wooded areas has increased the potential for contact with wildlife and their ticks. The abundance of I. scapularis has been directly related to the number of white-tailed deer. The exclusion of deer from large areas by fencing has been shown to reduce tick abundance. Substituting landscape plants, which are less palatable to deer, may discourage browsing around the home. Mouse nesting sites in stone walls and woodpiles should be kept brush free. Move firewood and bird feeders away from the house.
Reduction in abundance of I. scapularis with a 7-strand, high-tensile electric deer fence at an 18 acre property in Lyme, Connecticut, at all plots inside the fence and plots located > 300 feet inside the fence.

Landscape modifications . . .
Ixodes scapularis is most abundant in woodlands where hosts for the tick flourish and where high relative humidities necessary for its survival exists. Ticks also may be found on well-maintained lawns, particularly those adjacent to woodlands. The majority of I. scapularis on lawns has been recovered within 3 yards of woodland or stone wall edge.
Altering the landscape to increase sunlight and lower humidity may render the area less hospitable to the tick. Close-cut lawns with substantial solar exposure appear to have fewer ticks. To reduce ticks, prune trees, mow the lawn, remove leaf litter accumulations, clear underbrush in woodlots, and cut grass, weeds, and brush along edges of the lawn, stone walls, and driveways. Ticks may also be found in groundcover such as Pachysandra.

The removal of leaf litter can drastically reduce the number of I. scapularis nymphs on some properties. Mowing and removing cover vegetation also will discourage host rodents. Wood chip and tree bark borders, gravel, or similar materials between woods and lawn may reduce tick abundance on the lawn by approximately one-half, on average. Results have been found to vary from home to home.

Chemical control . . .
Acaricides (pesticides or insecticides that kill ticks) may be applied to lawns and woodland edges to kill ticks around the home. Commercial applicators can be hired to treat for ticks in the yard. Many pesticide products are restricted to licensed pesticide applicators. The optimum time of application for a spray application to control the nymphs would be mid-May to early June. A fall application may be used to control adult I. scapularis. Both liquid and granular formulations have been reported effective against I. scapularis. For liquid formulations, use sufficient spray volume and pressure for thorough coverage and penetration of the vegetation and leaf litter. Wooded areas adjacent to the home should be treated for maximum effectiveness. Most of these chemicals are highly toxic to fish and other aquatic organisms and application to or near water should be avoided.

Acaricides (pesticides) registered for the control of ticks in Connecticut include the following 11 chemicals.

  1. Bifenthrin (Talstar). Chemical class: pyrethroid. It is available as a spray or granular formulation for commercial licensed applicator use only. Labeled for tick control on the lawn.
  2. Carbaryl (Sevin, other brands). Chemical class: carbamate. A commonly used garden insecticide. Available as a spray or granule for ticks on turf and recreational areas.
  3. Chlorpyrifos (Dursban, other brands). Chemical class: organophosphate. Labeled for tick control on turf and recreational areas. Some products are available for public use, most are restricted to licensed applicators. Available as a spray or granule.
  4. Cyfluthrin (Tempo, other brands). Chemical class: pyrethroid. Labeled for tick control on turf. For commercial licensed applicator use only.
  5. Deltramethrin (Suspend, DeltaGard G). Chemical class: pyrethroid. Available as a spray or granule. Labeled for tick control in residential areas where ticks may be found.
  6. Diazinon (Diazinon, other brands). Chemical class: organophosphate. Some products are available to the public, but many are restricted by label to commercial use.
  7. s-fenvalerate (Zema Lawn Spray). Chemical class: pyrethroid. This product is a hose sprayer kit for homeowner use and may be used against ticks on lawns and backyards.
  8. Fluvalinate (Mavrik Aquaflow, Yardex). Chemical class: pyrethroid. Labeled for tick control on turf and ornamentals.
  9. lambda-cyhalothrin (Scimitar). Chemical class: pyrethroid. For commercial licensed applicator use only.
  10. Permethrin (PermaKill 4Week Tick Killer). Chemical class: synthetic pyrethroid. It is labeled for use against ticks on the lawn. Permethrin is highly effective as a clothing toxicant against ticks as a tick repellent formulation.
  11. Permethrin (Damminix®) Permethrin-treated cottonballs target larvae and nymphs of I. scapularis on white-footed mice, which collect the cotton as nesting material from tubes distributed throughout the mouse habitat. Studies in Connecticut and New York state failed to show any reduction in the number of infected, host-seeking I. scapularis nymphs when this product was used for a three year period in woodland and residential areas of about 4 acres or less. Nymphal reductions were reported in a Massachusetts study with the treatment of one 18-acre site.

Pyrethrin (Pyrenone, Kicker, Organic Solutions All Crop Commercial & Agricultural Multipurpose Insecticide) Pyrethrins are derived from the chrysanthemum plant. They are often combined with the synergist piperonyl butoxide (PBO), which increases the killing power of pyrethrin ten-fold. While insecticidal soap, spreader sticker agents, and other agents can enhance the effectiveness of pyrethrin, pyrethrin and insecticidal soap or pyrethrin and PBO alone is not very effective against ticks. By contrast, pyrethrin and PBO with either insecticidal soap or silicon dioxide (diatomaceous earth) was found effective against ticks when applied with a hydraulic sprayer. Thorough coverage appears vital for these materials to be effective. There is little or no residual activity with pyrethrin and insecticidal soap. However, silicon dioxide works mechanically through abrasion and desiccation and may provide some residual effect.