Temperature
The life cycle of a red spider mite can range from a few weeks to a month, depending on the temperature of their environment. In temperatures in the upper 80s and above, mites are born, become adults, lay eggs and die, all within a week or so. In lower temperatures, the process slows down, though the number of eggs produced is roughly the same.
Eggs
Eggs are typically laid in small groups on the underside of leaves, often near its veins. During her lifespan, one adult red spider mite can lay more than 100 eggs.
Middle Stages
Eggs hatch after four to seven days, depending on warmth and humidity. At this larval stage, mites have six legs. Within about six days, they will pass through the protonymph and deutonymph stages, during which they add two more legs.
Adults
Adult spider mites can live anywhere from 10 to 30 days. The female will begin laying new eggs after about three days as an adult, producing five or more eggs in one day.
What They Eat
Throughout their lives, spider mites feed on plant cells. Plants and flowers that have an infestation of mites will show feeding marks: small, yellow specks. A silken web can also often be detected. Plants left untreated will turn brown and die.