Ditylenchus dipsaci is widespread in southern Italy. It reproduces on several wild and cultivated plant species. Among vegetables, the most severely damaged are onion and garlic, but broad bean, pea, and celery also suffer damage. In the Mediterranean area the nematode mainly infects host plants from September to May, but reproduction is greatest in October, November, March, and April when soil moisture, relative humidity, and temperatures are optimal. Symptoms of nematode attack are apparent in the field in late February to April and in nurseries in October and November. As a result, early crops are damaged more than late crops. Nematodes survive in the soil and in plant residues. However, seeds from infested plants, except those of broad bean and pea, have rarely been found to harbor nematodes. The use of seeds, bulbs, and seedlings free of nematodes is a prerequisite for successful crop production. Cropping systems, soil treatments with fumigant and non-volatile nematicides, and s
