TICKS
Click on a species of ticks below to learn further information.
Ticks are leathery-bodied, eight legged arthropods with mouthparts that are suited for holding tightly in
the skin and sucking blood. Ticks feed exclusively on the blood of warm blooded animals; and they can
transmit diseases. All ticks, as well as mites, spiders and scorpions belong to Class Arachnida with the Phylum
Arthropoda.
There are two general types of ticks: The hard ticks belonging to the Family Ixodidae, and the soft ticks
belonging to the Family Argasidae. The ticks of primary concern in structural pest control are a few species of
hard ticks. These are addressed in the next few pages.
The soft ticks are different from the hard ticks in that their entire skin cover (integument) is of the same
bumpy or granular texture throughout; their mouthparts are on the underside of the body and do not protrude out
in front; and they invariably are associated with the nest or dwelling place of their host animal. The hard ticks,
however, do no wait passively in the host’s nest or dwelling place for their food to come to them. Most of
them stand perched on a wall or blade of grass or shrub ready to pounce of their host when it comes near.
The hard ticks that are primary concern to the PCO are the brown dog tick, and couple of "wood ticks".
Their biologies are similar, but the indoor habitat of the brown dog ticks makes it different from the other hard
ticks. The brown dog tick feeds mainly on dogs, and not on man. The other hard ticks feed on man as well as
other animals. Because of this, the control methods for the brown tick differ somewhat. And this makes
identification very important. Wall surfaces around windows and doorways in a residence is the best place to
treat for brown dog ticks.
The hard ticks are so named because they have a hard shield (scutum) on their dorsal side. This shield
covers the front one—third of the dorsal side of the non-engorged female, and the entire dorsal side of the male.
When the male feeds, it does not become dramatically enlarged as does the female.
General Life Cycle of the Main Species of Hard Ticks
(The brown dog tick, and two wood ticks: the Rocky Mountain wood tick-also known as Rocky Mountain
spotted fever tick; and the American dog tick)
There are four stages in the life cycle of these ticks: egg, larva, nymph and adult. These hard ticks are
called “3-host-ticks", as can be understood from the following abbreviated life cycle description:
"Female lays many eggs. Eggs develop into —legged larvae (called "seed ticks"). These larvae attack the
1st host, thereby receiving their 1st blood meal. Larvae then drop from 1st host to late emerge from the larval skin
into 8-legged nymph. These nymphs attack 2nd host, receiving 2nd blood meal, and then drop from 2nd host.
Next, adults emerge from the nymphal skin. These unfed adults attack the 3rd host getting a third blood meal
and becoming engorged - and then they mate. The engorged, fertilized female drops from the 3rd host, lays her
several hundred or a few thousand eggs, and then dies." Each of the three hosts could be the same animal or a
different animal. A 3-host tick requires a blood meal fro each of the 3 hosts. Ticks are said to have a very good
sense of smell, so that they can detect when the proper host animal draws near and then move toward it.
An unusual thing about these particular ticks is the change in the appearance of the adult females that
comes from feeding. The adult males do not change very much. But as the females become engorged, they
become much larger (about 1/2") and tum gray. At this point they are relatively immobile because of their
unwieldy size. The smaller 8-legged nymphs of both sexes also turn gray when they become engorged.
The tick prefers a warm, dry indoor environment. It seldom develops heavy infestations outdoors and
does not live in the woods. Instead, it has its habitat wherever dogs occur.
Diseases Transmitted by Brown Dog Ticks and Wood Ticks
Ticks are very efficient transmitters of diseases for a number of reasons. Among these reasons: They
attach firmly to the host and suck blood; they feed slowly and can transmit pathogens (germs) from one
generation to the next by their eggs;. and also from one life stage to the next (egg to larva to nymph to adult).
Among the diseases transmitted are Rocky Mountain spotted fever and tularemia; and they also can cause tick
paralysis.
Notes on Tick Control
- American dog ticks occur primarily outdoors, so control should be done outdoors in addition to indoors (although the tick cannot complete its life cycle in a dwelling unit).
- If unchecked, successive generations of brown dog ticks can develop in dwelling units.
- Crack and crevice treatment using a long-lasting residual insecticide is the best way to control a tick infestation inside a residence.
- For effective tick control the infested areas should be treated with a residual acaricide, and, if a dog lives there, the dog should be treated at the same time. Treatment of the dog alone or the premises alone will not provide control.
- Space sprays of pyrethrins or DDVP are not effective indoors except when used in conjunction with a residual application. After applying the residual, a fog or mist can drive many ticks out of hiding and over the residual application.
- For entrenched infestations, its best to plan on one re-treatment. Some ticks may remain hidden for several days or a few weeks and not emerge until after the pesticide has lost its effectiveness.
- The Western black-legged Tick is a bloodsucking ectoparasite and is a vector known to carry and spread Lyme disease in California.
- The best preventative measures to take for tick control in and around a residence is to keep the grass and weeds cut short, remove bird and rodent nests around structures and seal entrance points of hosts.
Click on a species of pest below to learn further information.