Spider mites

Spider mites are very small spiders that appear on the backside of the leaves and destroy them by sucking. You can see the spider mites with a loop; they are reddish or yellow.
Spider mites attack mainly the leaves of the roses who are growing in conditions with low relative humidity; roses in pots are an example.
Frequent mulching and watering and applications of sulfur are very beneficial to avoid spider mites attacks.
Application of chemicals is sometimes inevitable.