There are nearly 900 species of ticks in the world. With so many ticks, it’s easy to assume they don’t all look alike. Nature is diverse and the tick participates fully in that diversity. From their color, appearance and the diseases they carry, ticks are all different. In the US, there are 7 tick species we see most often.
There are four stages in a tick’s life cycle. Egg, larvae, nymph and adult make up the stages of the tick’s cycle. The average tick life span in the US is 2 years. Another common thing about our ticks is that they all need a blood meal to move onto the next stage of their life cycle. It is during this search for blood that they become infected with bacterial infections.
No tick is born infected. Lyme Disease, Anaplasmosis, Babesiosis, Rocky Mountain Spotted Fever, Ehrlichiosis, Tularemia and other infections are all ones they may contract from one of their blood meals as they mature. If the animal they receive the blood from is infected, they will become infected also. Some ticks never get an infection. A tick’s probability for an infection is proportional to the degree that their blood hosts are infected.
Since no tick is born infected, tick eggs carry no infection. When an egg develops and the tick needs to move onto the larvae stage, a blood meal is needed. Since most of the tick eggs that hatch are in the nests of white-footed mice, the mice are often the larvae ticks’ first blood meal. Both female and male ticks need this meal, so both are susceptible to an infection. Larvae ticks are very small and are often not seen by us.
White-footed mice have an infection rate for the Lyme bacteria of 90-95% in many areas. It is at this stage that ticks first become infected with Lyme Disease.
In the spring of the tick’s second year, they molt into nymphs and need a second blood meal. This also is often taken from the white-footed mouse. But nymph ticks are now mobile. Male and female ticks both may hitch a ride and be dropped off the back of the mouse outside the nest and may need to feed on more than one animal to get a complete blood meal. It is at the nymph stage that both male and female ticks are most likely to infect humans. They are no larger than a poppy-seed so still difficult to spot on our skin. They have also taken two blood meals, often from more than one animal, and their probability of having an infection is the highest it will be in their life cycle.
In the fall of their second year, nymph ticks are now adults. Females are quite large and they are in search of a blood meal sufficient to give them the energy to produce their eggs, often more than 1,1000 of them. Because of the size of an adult tick they need a larger blood meal, therefore a larger host. In MA and most of the areas where ticks are prevalent, that large host in the environment is the white-tailed deer and occasionally a human or pet. One adult deer can provide blood meals for hundreds of female ticks. Since the male tick will not be laying eggs, they will attach to deer in order to mate with the females. Male ticks in their adult stage have no need for any of the deer’s blood.
When you find a tick, it is helpful if you can identify the specie. The chart here will help the next time you find a tick on yourself, a family member or a pet. Knowing the specie will help your physician know the diseases in which you may have been exposed. If you do find a tick and are concerned about a tick infection, it’s always a good idea to seal it in a plastic bag with a moist cotton swab. Identifying he tick specie will narrow the likely type of infection you may have and it can be tested for the bacteria it carries.
You can see from the chart that ticks look very different before being engorged from their blood meal versus after they have taken it. Note the round smoothness of the Deer Tick and the indentations on the other species. Both the Dog Tick and Lone Star Tick have reddish brown and brown legs. The Deer Tick has black legs, as its other name suggests.
We are approaching the time of year that females will be looking for their last blood meal. Their larger size now allows us to find them on our skin more easily than earlier in the summer when they were nymphs. However, they are just as likely to be infectious to our pets and us if we are bitten.
Mosquito Squad of the North Shore provides barrier treatment services to homeowners that will protect you from both tick-borne and mosquito-borne infections. Our barrier treatment is effective in eliminating 85-90% of the ticks and mosquitoes around your home. The best way to know you won’t get one of these infections is to prevent yourself from ever being bitten. Our barrier treatment is an effective step in providing that protection.
To learn more about our highly effective tick tube program and barrier sprays, contact Mosquito Squad of the North Shore.