Narrative

Galls found on Artemesia tridentata.

This lifeform is widespread in North America.

Eriophyid mites are tiny creatures hardly visible without some type of magnification. These are worm like with only 2 pairs of legs. Many species are serious plant pests.

Ticks and Mites (Order Acarina) are a large order that has considerable economic importance to man. There are probably more than 30,000 species in this order. Included are several tick species that are known for transmitting serious diseases such as Rocky Mountain Fever and Lime Disease.

Arachnid (Class Arachnidae) consists of nine to eleven different surviving orders depending upon how one divides the Arachnid class. In total, there are about 60,000 to perhaps 75,000 species grouped in the following eleven orders:

Order - - - - - - - Number of Species

Acarina-Mites and Ticks - 30,000
Amblypygi-Tailless Whipscorpions - 60
Araneae-Spiders - 35,000
Palpigrada-Micro Whipscorpions - 50
Ricinulei or Podogona-Ricinulids - 20
Pseudoscorpionida-False Scorpions - 1,000
Schizomida-Short Tailed Whipscorpions - --
Scorpionida-Scorpions - 2,000
Solpugida-Sun Spiders, Windscorpions - 1,000
Phalangida-Daddy Long Legs - 2,200
Uropygi-Whipscorpions - 70

The old order, Pedipalpida (Whipscorpions), has been divided into the following orders:
Uropygi - (Whipscorpions)
Ambylypygi - (Tailless Whipscorpions)
Schizomida - (Short Tailed Whipscorpions)

Jointed Legged Animals (Phylum Arthropoda) make up the largest phylum. There are probably more than one million different species of arthropods known to science. It is also the most successful animal phylum in terms of the total number of living organisms.

Butterflies, beetles, grasshoppers, various insects, spiders, and crabs are well-known arthropods.

The phylum is usually broken into the following five main classes:
Arachnida: - Spiders and Scorpions
Crustacea: - Crabs and Crayfish
Chilopoda: - Centipedes
Diplopoda: - Millipedes
Insecta: - Insects

There are several other rare classes in the arthropods that should be mentioned. A more formal list is as follows:

Sub Phylum Chelicerata
C. Arachnida: - Spiders and scorpions
C. Pycnogonida: - Sea spiders (500 species)
C. Merostomata: - Mostly fossil species

Sub Phylum Mandibulata
C. Crustacea: - Crabs and crayfish

Myriapod Group
C. Chilopoda: - Centipedes
C. Diplopoda: - Millipedes
C. Pauropoda: - Tiny millipede-like
C. Symphyla: - Garden centipedes

Insect Group
C. Insecta: - Insects

The above list does not include some extinct classes of Arthropods such as the Trilobites.