To view, tap a leaf over white paper and inspect for crawling dots. Mites are barely visible to the naked eye.Heavy feeding causes yellowing, browning, and even leaf death.Inspect top of leaves for fine stippling and underneath for fine webbing.
Look for fading leaves, especially older ones.Spider mite damaged bean leaves Monitoring It is very difficult to see mites without a hand lens (magnifying glass).There is visible webbing on leaves when mite populations are high.Heavy mite infestations stunt plants and fruits, and premature leaf drop may occur.Plants lose vigor and become unthrifty.Spider mites' puncture-and-suck mode of feeding produces yellow or white stippling and leads to reddish or pale discoloration of leaves.(European red mites feed on tree fruits and ornamentals.) Also found on numerous other vegetables such as beet, carrot, corn, eggplant, parsley, pea, pepper, and sweet potato, as well as strawberry, blackberry, and other fruits.Primarily infest bean, tomato, and cucurbits (cucumber, squash, melons).Populations develop and increase rapidly in hot, dry conditions.Mites also spin fine webbing, hence their name.Feeding occurs primarily on leaf undersides and is visible on the upper surfaces as stippling.Mites suck chlorophyll from leaf tissues, creating fine white spots referred to as stipples.The twospotted spider mite is the most common species in Maryland vegetable gardens.Adults overwinter in plant debris or under bark and produce multiple generations yearly life cycles can be as short as 8 days.