Vogelknöterich
"D. dipsaci" is a microscopic worm about 1.5 mm long. It penetrates into plants from either the soil or infested planting material and occasionally from seeds. They live between the cells of onion or garlic leaves and between the scales of the bulbs where they feed on cell sap and multiply. The female lays 250 eggs during a season and six generations may develop under optimum conditions when the temperature is in the range 15–20 °C. As the number of nematodes increase, symptoms become visible. Onion leaves start to curl, garlic leaves become yellow and die, bulb scales are loosened, and bulb necks become cracked. Development continues in infested bulbs during storage. "D. dipsaci" is not restricted to onions and garlic. Its other plant hosts include peas, beetroot, vegetable marrow, pumpkin, rhubarb, and ornamental bulbs. Some weeds also act as hosts, including "Stellaria media", "Linaria vulgaris", "Polygonum aviculare", "Fallopia convolvulus", and "Galium aparine".