FLORIDA TICKS & MITES
A source for information on ticks
SOFT TICKS Family
After the egg stage, six-legged soft tick
larvae immediately seek blood meals and undergo a molt. Following this molt, soft ticks enter the
nymphal stage, during which time they undergo several more molts. Soft ticks grow larger after each molt and
feed many times during this stage of development.
Unlike hard ticks, soft ticks do not have a protective scutum.
Their mouthparts also are not readily visible when viewed from above. These mouthparts consist of two palps and one
hypostome. The barbed hypostome is capable of penetrating human skin and is not easily removed. In some cases, the
hypostome may remain within the host even after the soft tick has been removed.
Some common soft tick species are the fowl tick and the
relapsing fever tick. Like hard ticks, soft ticks are known to be vectors of various bacteria and diseases. Among
them are Lyme disease, Rocky Mountain spotted fever, babesiosis, ehrlichiosis, tularemia and tick-borne relapsing
fever. Proper removal of soft ticks is necessary to prevent infection.
A pair of bent-nose tweezers should be used to remove the
tick. Take care not to puncture the body of the tick, as this can release more harmful bacteria.
Characteristics and Habits SOFT TICKS (Family Argasidae)
Male and female soft ticksare similar in
appearance, with no dorsal plate (scutum) to distinguish the sexes as in hard ticks. The capitulum which
bears the mouth parts is located beneath the anterior margin of the body. The spiracles or respiratory
openings lie on the sides of the body above the third and fourth pairs of legs. Although some species of soft
ticks feed on humans, they are more common on birds and occasionally are found on bats and other small
mammals. The sexes can be distinguished by the shape of the genital opening which in males is circular or
crescent-shaped and in females is a transverse split, wider than long.
Ornithodoros is the most important of the four genera of soft ticks. The ticks in this genus have
a more globular body without the sutural line found in the various species of Argas. The body is roughened or
warty in appearance with tiny protuberances, called "mammillae." The hypostome has well-developed teeth.
Several species are known in the United States, including Alaska and Hawaii, of which four are known vectors
of relapsing fever in the United States.
The relapsing fever ticks,
Ornithodoros species, are
seldom seen by the average person since they are primarily "nest ticks" which can survive starvation for
months or even years. Human beings are occasionally bitten by these hungry ticks and contract cases of
relapsing fever in mountain cabins, in caves, or near wild animal burrows. For example,
O. hermsi is found at high
elevations in the West, particularly Idaho, Oregon, Washington, California, Nevada, and Colorado, where it
parasitizes small mammals such as the western chipmunk (Eutamias) or tree squirrels
Occasionally, people sleeping in mountain cabins come in contact with infected ticks and contract relapsing
fever. Ornithodoros parkeri is a large species which attacks man and rodents and is found in nine western states.
It is an efficient vector of relapsing fever and can transmit Rocky Mountain spotted fever.
Ornithodoros Turicata, also a
large tick, is found in the southern and western United States. It is found in caves, holes made by burrowing
animals and at campsites. Its hosts include rodents, snakes, terrapins and various domestic animals, as well
as man. Even after long starvation, it is an efficient vector of relapsing fever. Both
O. Turicata and
O. parkeri transmit the
spirochete of this disease to their offspring as far as the fourth generation. Ornithodoros talaje occurs in southern