Ticks belong to the arachnid class and are related to mites and spiders. These external parasites feed on the blood of mammals, reptiles and birds. Approximately 850 species of ticks have been identified worldwide and more than 25 species are found in Arizona. Ticks are the No. 1 carriers of diseases to humans in the United States, according to eMedicine Health. The bite of a tick transmits organisms, secretions and toxins through the saliva that spread disease.
Types
The Rocky Mountain wood tick, the brown dog tick and the adobe tick are the three most common types of ticks found in Arizona. The wood tick and dog tick are classified as hard ticks belonging to the Ixodidae family. Hard ticks have a stiff back plate, and tend to attach and feed on a host for hours or days. The transmission of disease from a hard tick usually occurs near the end of feeding when the tick becomes full of blood. The adobe tick belongs to the Argasidae family and is classified as a soft tick. The appearance of a soft tick differs because of a more rounded, soft body without the hard plate. These ticks usually feed for less than one hour, and disease transmission from these ticks occurs in less than one minute.
Life Cycle
The egg, larva, nymph and adult are the four stages of a tick life cycle. In every cycle, ticks require blood from a host in order to live and complete their development. When a tick hatches from an egg, the six-legged larva finds a blood meal from a host and molts into an eight-legged nymph. In the adult stage, a meal of blood allows the female to lay eggs. She deposits as many as 5,000 eggs before dying. At any stage of development, ticks are able to survive for months without feeding.
Disease
Ticks feed by sucking whole blood from a host, extracting the water from the blood and injecting the water back into the host. Among arthropods, ticks spread the widest assortment of pathogens, including viruses, bacteria, protozoa and rickettsiae. The most prevalent tick-borne disease in Arizona is Rocky Mountain spotted fever (RMSF). The brown dog tick carries this disease from host to host with the primary host being dogs, but these ticks also feed on humans. The Rocky Mountain wood tick, found only in brushy areas in the upper northern region of Arizona, also carries RMSF.
Prevention
To control and prevent ticks in Arizona, frequently examine pets and remove any ticks with tweezers or forceps. Maintain a shortly mowed lawn and remove any brush, leaves and woodpiles around the house and at the edge of the yard. Avoid walking in tall grasses and weeds, tuck pant legs into socks, wear light colored clothing so ticks are visible, and use a tick repellent spray.
Tags: from host, Rocky Mountain, wood tick, adobe tick, blood from, blood from host, brown tick