[All pictures of garden wildlife on this page are thumbnails. Click on any thumbnail for a large format to be displayed.]

Spiders and the like (Araneae etc.)

The contents concerning spiders is split into multiple pages: 1 House Spiders, 2 Garden Spiders, 3 Mites and Ticks, 4 Harvestmen, 5 Pseudoscorpions

Introduction to spider-like arthropods

It is considered to be easy: all small animals with 6 legs are insects and all small animals with 8 legs are spider-like arthropods. But actually possessing 8 legs does not mean that these animals are closely related as the insects are. Yet it is a practical solution to group the numerous species found in taxonomic class 'insects'. Small creatures walking on 8 legs are usually well known: spiders, harvestmen, scorpions and ticks. Yet the animals differ considerably from one another. Spiders have a body consisting of three parts. Similarily to insects have: head, thorax and abdomen. The head and thorax have fused into one visible structure called the cephalothorax. Ticks have only two bodyparts: head and body. Harvestmen's body has one part, the body itself. These differences make it obvious that these animals are not closely related whatsoever. To make it even more compliceted, these 8 legs are not always there. A newly born mite or tick has only 6 legs. Worldwide there is a considerable number of various spiders. The same goes to mites even though many species can hardly ever be seen. They are small and most live as parasites on mammals, birds or insects. There are far less harvestmen species. Of the pseudoscorpions only some 15 species are present in the Benelux. Many spiders and harvestmen are relatively big in size while pseudoscorpions and mites are much smaller. Many species can hardly be seen by the naked eye.

The size of the House Spider to the left is about 18 mm which makes it a true giant in this part of the world. Mites, like the ones on the bumblebee to the right, often hardly reach a length of one millimeter.

Spiders belong to the arthropods, just like insects and many other animals do. Many people therefore think that spiders are insects, but that is not true. Spiders have 8 legs, insects only 6. Spiders have 6 or 8 ordinary eyes, insects have two compound eyes. Although spiders are much smaller they are more related to scorpions and crabs. Many spiders, though not all, are capable of producing threads. Some use these wires to enwrap the eggs or the young. Other species build a web used to catch prey. Underneath the web you can sometimes find a bone yard full of body parts of insects the spider can not eat. These are, for instance, legs or wings. Especially under the web of the vibrating spiders you'll see such remnants of their vistims.

To the left: spiders may be quite beautiful but most of us find them very scary! To the right a bone yard under the web of possibly a vibrating spider.

Spiders are not among the easiest animals to identify. Many bear no markins or if they do the markings they are identical to those of other species. The colouring does not help either. Young animals' colours differ from the adults'. Moreover, many spiders show either all kinds of colour, such as the European Garden Spider and the Goldenrod Crab Spider, or have completely indistinct colouring. Adult female spiders can be identified by looking at the epigyne. This is the part of the sexual organs outside the spider's body. Sometimes you even need a microscope to see it, but in some cases it is visible to the naked eye. Especially orb-web spiders have an epigyne that can easily be seen. This little organ is situated in a rather peculiar place: somewhere half way the body, just behind the legs. You probably expected it somewhere near the end of the body, for that's the place the sexual organs of for instance insects are at. However, spiders use the end of their bodies other important function which is spinning threads for their webs. Therefore the end parts of their bodies are reserved for for other organs called the spinnerets.

To the left the spinnerets, to right the epigyne, just behind the legs. In this case both belong to the European Garden Spider.

Many people suffer from 'arachnophobia' which means they have a fear of spiders. In Europe there is no real need to be scared of spiders because only very few spiders are capable of penetrating the human skin. Those which can, will only bite if they feel threatend. Actually spiders should be treated with respect because they are very useful animals that help tremendously to control the number of insects. Without spiders we wouldn't be able to be outdoors in summer as it would be swarming with nasty mosquitoes, gnats, flies and wasps. Also mites are quite useful because many species eat aphids. Some mites however are quite a nuissance, those that suck blood of mammals, birds or insects. Humans suffers from the ticks because of their bites and from the consequences of their bite: the dangerous Lyme disease. Certain mites are a nightmare to bee-keepers as they can be extemely devastating to bee populations. Pseudoscorpions are too small to be a bother to humans. All spiders are active hunters, especially the harvsetmen. Some daddy long legs are deliberately introduced in agriculture areas to get rid of harmful insects as a biological weapon and an alternative to using pesticides.

Both the small pseudoscorpion to the left and the much bigger harvestmam to the right are fanatic hunters.