Spider mites are a distant cousin of the spider. But unlike their cousins, spider mites are very hard to see with the naked eye. Because of this, it can be hard to tell if your plant has a spider mite infestation until they have damaged your plant. Fortunately, most plants do not end up dying from spider mite infestations and this disease can be fairly easy to control.
Damage to the plant
As mentioned before, the spider mite is mainly recognized by the damage they impose on a plant. Spider mites are often found on the bottom of plant's leaves, where they absorb the plant's nutrients. This causes many brown dots to form on top of the plant's leaves, which over time, turn yellow and fall from a lack of nutrition. Like larger spiders, spider mites also leave a trail of webs, which are not directly harmful to plants, but don't look very pleasing to the eye.
If the spider mite infestation is not too large, remove the infected leaves, taking care not to infect the healthier ones. It can also help to spray your plants with cold water. A good solution is to add 2% hand soap and 1% spirit to a water sprayer filled with water, which you can then spray over your plant. The spider mite can reproduce extremely quickly, so it is also very important that any spider mite eggs are also sprayed and removed from the leaves. Spray and check your plant's leaves several times a week until the disease is gone. If none of this works, look for a biological pesticide.
Spider mites prefer a warm and dry environment, where they can reproduce better. Old potting soil is one of their favourite nesting places, as well as unhealthy plants. Spider mites enter the house in the same way as most other diseases; through drafts, clothing or pets.
Spider mites dislike high humidity and cooler temperatures. So spraying your plant with water every now and then is a great idea. And replacing your plant's potting soil or re-potting your plant every few months can also help prevent spider mites.