Tag: windscorpion

Bug of the Week: All About Arachnids

We’ve never discussed arachnids in detail here at Bug of the Week. Let’s find out what we’ve been missing.

Spiders and their relatives belong to the class Arachnida. How can you tell whether a creature belongs to this group? Arachnids have two body regions called the prosoma (part with eyes and legs) and opisthosoma (rear section). Arachnids have eight legs and they do not have antennae, although they do have two short appendages in front called pedipalps that sometimes may be mistaken for antennae.


Although almost anyone can recognize a spider, there are a number of related arachnids that are less well known.

Scorpions (Order Scorpiones)


Scorpions have are pincer-like pedipalps  and their opisthosoma is elongated into a relatively thick tail with a stinger on the end.

Like most other arachnids, scorpions are nocturnal. They come out at night to catch insects and other arthropods.

Related posts:


(Public domain photograph by Alex Wild)

These tiny creatures have pinchers like scorpions (red in this photograph), but have no tail and no stinger. They are often found in compost heaps where they feed on even smaller insects and mites.

Wind Scorpions or Sunspiders

sunspider1These desert arachnids have large chelicerae or jaws that they use for catching insects. They can also use their jaws to stridulate, or make a noise. They don’t have a tail.

Related post:  Sunspiders

Whip Scorpion or Vinegaroon


Unlike all other arachnids, the whip scorpions have a thin tail at the end of the opisthosoma. The pedipalps are robust. In contrast the first pair of legs are thin and have a sensory function similar to antennae.

Vinegaroons have vinegar in their names because they can spray high concentrations of acetic acid if threatened.

Never seen one before? BBC Earth Unplugged has a video of one spraying.


Mites and Ticks (Order Acarina)

mite-red-closeThe two body regions are difficult to see in mites and ticks. Their bodies are unsegmented, like small blobs. Also, their legs tend to be quite short relative to their body size.

Certain kinds of mites are among the few arachnids that feed on plants. The red mite in the photograph is an insect predator.

Daddy Long-legs or Harvestman (Order Opiliones)

daddy-long-legLike the mites, the harvestman have what looks like a single oval body region. Unlike the mites, they have long thread-like legs.

Harvestmen differ from spiders by possessing fewer eyes, having only two rather than six or eight. They also lack both venom and silk glands.

Some species of harvestmen are omnivores or scavengers rather than true predators.

Want to learn more?

A few spider identification basics

Check out our growing list of children’s books about spiders


What would you like to know about arachnids?

Bug of the Week: Sunspiders

“What is it?” the woman asked, and handed me this creature. “Cool,” I said, which is probably not what most people would say :-).

It turns out I knew exactly what it was. This fearsome-looking invertebrate has a number of common names, such as sunspider, windscorpion, camel spider, solfugid or solpugid. It belongs to the order Solifugae, which contains approximately 12 families.

Sunspiders are unique to deserts. They are not true spiders nor scorpions, but they are arachnids. They have eight legs, plus a pair of leg-like appendages in the front called pedipalps. The pedipalps have sensory functions, like the antennae of insects, and also hold and manipulate food items.

The features that catch most people’s attention, however, are the large jaws or chelicerae. They use the chelicerae to catch insects and other small animals.

Can you see the dark spots in the middle of the head behind the chelicerae? Those are the eyes.

Sunspiders hunt at night, like most other arachnids. They can move very quickly to grab prey. They are also thought to be scavengers, eating dead insects as well as live ones.

The good news is that sunspiders are not venomous and most of the small ones are pretty much harmless to humans. They are likely to run away if startled. In fact, little is known about these shy desert inhabitants.

Have you ever seen a sunspider?


To find out more about camel spiders, see National Geographic.

Author Sandra Markle has a new children’s picture book, with the slightly misleading title:  Wind Scorpions: Killer Jaws (Arachnid World). (I guess they are killer jaws if you are a cricket.)

Library Binding: 48 pages
Publisher: Lerner Publications (February 1, 2012)
ISBN-10: 0761350489
ISBN-13: 978-0761350484

Disclosures: The book was from our local library. Also, I am an affiliate for Amazon. If you click through the linked titles or ads and make a purchase, I will receive a small commission at no extra charge to you. Proceeds will be used to maintain this self-hosted blog.