Spider Mites

Spider mites are so small that you sometimes cannot see them with the naked eye. They are classed in the spider family and not the insect order. 

Spider mite colony-Clemson University, Spider Mites-University of California

Description 
They are always found in colonies. Full grown mites have 8 legs and immatures have 6. They can be different colours and almost resemble aphids. Indications of severe infestation is the presence of webbing.

Spider Mite Eggs-University of California

Habitat and Lifecycle
They are found in all parts of the world. They lay their eggs in the spring and overwinter as adults in leaf trash and ground litter. In some warmer climates mites may feed all year. Eggs are translucent and resemble tiny droplets of water. Females can lay up to 12 every day for weeks in summer months. Spider mites peak in the summer months and flourish in the heat. Their lifecycle can be finished in less than1 week if conditions and food is abundant.

Damage-University of California

Diet and Damage
They are sucking pests and can be found on the undersides of the leaves. These mites spin small webs so that is an indication as to what you have bothering your plants. They will attack almost any plant including house plants, ornamentals, trees, shrubs and veggies. The first sign of leaf damage is small dots on the top side of the leaves. Eventually leaves will turn yellow and fall off. Eventually the plant will die. Damage can be severe where the colonies are numerous.

Control
1) Hand Pick
Flip over the leaves and gently shake them off into soapy water. They will move rapidly once they are disturbed so act quickly.
2) Garden Sanitation
Keep your garden free of debris and remove all debris from your property. Sometimes it helps to put your wastes around the perimeter of your property to make shelter for the beneficial bugs to overwinter in.
3) Natural Predators
Pedatory mites, pirate bugs, big eyed bugs, lady bugs and lacewings are among the natural preditors.
4) Water
A hard spray of water will knock them off and keep dust from accumulating on the leaves.
5) Insecticidal Soap
A soap spray will kill mites at the earliest signs before webbing occurs.
6) Horticultural Oils
Plants treated with organic horticultural oil will help prevent colonies from developing.