Minnesota Arachnids

Arachnids are a diverse class of jointed-legged arthropods (invertebrates) in the subphylum Chelicerata. While often confused with insects, arachnids are distinguished by having eight legs, no antennae, and two main body segments: a cephalothorax and an abdomen.

Arachnids by the Numbers

There are currently (February 9, 2026) 112,291 described arachnid species worldwide in 15,590 genera in 1,056 families in 16 orders worldwide, more than 12,500 species in 28 orders in North America north of Mexico, and at least 420 species in 167 genera in 4 orders in Minnesota.

Orders

In Minnesota, this class is represented by four primary orders: Harvestmen, Mites and Ticks, Pseudoscorpions, and Spiders.

• Harvestmen (Opiliones): Often called "daddy longlegs," these arachnids are characterized by a single, fused body segment and do not possess venom glands or silk-spinning organs.
• Mites and Ticks (Acari): The most diverse group of arachnids, ranging from microscopic soil-dwellers to parasitic species; they are critical to nutrient cycling and regional health ecology.
• Pseudoscorpions (Pseudoscorpiones): Small, secretive predators that resemble true scorpions but lack a stinging tail; they are frequently found in leaf litter and under tree bark.
• Spiders (Araneae): The most prominent order of arachnids in Minnesota, utilizing specialized spinnerets to produce silk for hunting, shelter, and dispersal.