Pest description and damage Mature bulb mites vary from about 0.02 to 0.03 inch (0.5 to 0.9 mm) long and have four pairs of legs. Their bodies are shiny, white, somewhat transparent, and smooth with reddish brown appendages. They are usually found in colonies. Their oval shape and sluggish behavior can deceive the human eye into identifying them as eggs. They avoid the light and hide under damaged or diseased tissue. Rhizomes infested with bulb mites may rot and fail to produce new growth, or new growth may be off-color, stunted, and distorted. Although the bulb mite is not considered a primary pest of rhizomes, it is often responsible for serious losses; the slightest injury to the rhizome will allow bulb mites to enter and become established. Once the mites are inside, they rapidly turn the rhizomes into rotten pulp. Injured or bruised rhizomes are the most susceptible to damage. Not only do mites destroy tissue, but they also carry fungi and bacteria which often spur additional damage. Millipedes may move into the rotting rhizomes which confuses the diagnosis.
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