Dermacentor andersoni

style="background:#Template:Taxobox colour;"|Dermacentor andersoni
style="background:#Template:Taxobox colour;" | Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Arachnida Subclass: Acari Superorder: Parasitiformes Order: Ixodida Family: Ixodidae Genus: Dermacentor Species: D. andersoni
Binomial name
Dermacentor andersoni Stiles, 1908
File:Dermacentor andersoni range map.svg

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Dermacentor andersoni, commonly known as the Rocky Mountain wood tick, is a species of tick well known for its transmission of Rocky Mountain spotted fever, Colorado tick fever, and tularemia. It can cause tick paralysis.

Life Cycle

General Tick Life Cycle

This image displays an example of the tick lifecycle, based on stages and the months that they are most likely to occur during.

• A tick's life cycle is composed of four stages: hatching (egg), nymph (six legged), nymph (eight legged), and an adult.
• Ticks require blood meal to survive through their life cycle.
• Hosts for tick blood meals include mammals, birds, reptiles, and amphibians. Ticks will most likely transfer between different hosts during the different stages of their life cycle.
• Humans are most often targeted during the nymph and adult stages of the life cycle.
• Life cycle is also dependent on seasonal variation.
• Ticks will go from eggs to larva during the summer months, infecting bird or rodent host during the larval stage.
• Larva will infect the host from the summer until the following spring, at which point they will progress into the nymph stage.
• During the nymph stage, a tick will most likely seek a mammal host (including humans).
• A nymph will remain with the selected host until the following fall at which point it will progress into an adult.
• As an adult, a tick will feed on a mammalian host. However unlike previous stages, ticks will prefer larger mammals over rodents.
• The average tick life cycle requires three years for completion.
  • Different species will undergo certain variations within their individual life cycles.

Spread of Tick-borne Disease

• Ticks require blood meals in order to progress through their life cycles.
• The average tick requires 10 minutes to 2 hours when preparing a blood meal.
• Once feeding, releases anesthetic properties into its host, via its saliva.
• A feeding tube enters the host followed by an adhesive-like substance, attaching the tick to the host during the blood meal.
• A tick will feed for several days, feeding on the host blood and ingesting the host's pathogens.
• Once feeding is completed, the tick will seek a new host and transfer any pathogens during the next feeding process.

Key features

• The larva only has three pairs of legs.
• The nymph has four pairs.
• A single pair of spiracular openings (stigmata) are seen close to the coxae (leg bases or segments) of the fourth pair of legs (except in larvae).
• A terminal capitulum (mouthparts) is visible from above in all hatched stages.
• A large sclerite called the scutum is present dorsally behind the capitulum. The scutum almost entirely covers the back of the male, but only partly covers the back of the female.
• Eyes, if present, are on the scutum.
• Sexual dimorphism in size and colour is frequent. The female is often larger.
• The posterior margin of opisthosoma is usually subdivided into sclerites called festoons.
• The pedipalps are rigid along the chelicerae, and are not leg-like.

Dermacentor andersoni Transmitted Diseases

The Rocky Mountain wood tick is known to transmit the following tick-borne diseases:

• Rocky Mountain spotted fever
• Colorado tick fever
• Tularemia

Geographic Distribution

• Rocky Mountain states
• Southwestern Canada 4,000 to 10,500 feet

Gallery

• Common name: Rocky Mountain wood tick
• Scientific name: Dermacentor andersoni
• Reservoir: small rodents (larvae and nymphs); large mammals (adult ticks)
• Geographic distribution: Rocky Mountain states
• Disease transmitted: Rocky Mountain spotted fever, tularemia

• 
  Rocky Mountain wood tick (Dermacentor andersoni)
  Adapted from CDC
• 
  Approximate distribution of the Rocky Mountain Wood tick
  Adapted from CDC