Spider mites are not spiders but a tiny insect that forms webs (hence the name):
This photo is an enlargement of another so that you can see the individual mites and the start of a web structure. These, and most of the photos in the gallery, were taken in our polytunnel where the mites have become a rather large infestation on our cucumber plants.
In this second image, you can see how just one leaf has become a huge colony of these tiny mites. A web has been created over a leaf forming an almost complete plastic-like sheath. Most of the mites are within the sheath but there are a few outside it. From examining the photos, most seem to have two spots on the fawn-coloured body but some appear to be plain and others are orange as you can see below – apparently there are hundreds of different types.
When I first started taking these photos I was puzzled as to why most of the mites were quite fuzzy – then I realised it was because they were inside of the sheath which seems to offer them a lot of protection from predators and, I think, a controlled environment.
In this third photo, you can see the formation of the sheath-like web – there is so much of it that it does look like some polythene sheet stretched across the plant. This one is across some of the stem and stalks of the cucumber plant. Look carefully and you can just make out the two dark spots on the bodies.
This final photo shows how I photographed these mites in the polytunnel (you can see the polytunnel frame behind the camera):
The camera is mounted on a focussing stage to aid the fine control I needed to get the insects in focus. The macro lens (an old Canon lens bought second hand 15 or more years ago) is attached to the camera with some non-Canon extension tubes. This helped to increase the enlargement (but I really need to obtain higher magnifications such as you can get with a higher powered macro lens but I cannot afford the £840 required…)
The full set can be seen in the pests section of the garden gallery.