Feeding, Egg-Laying, and Embryology of the Columbia Lance Nematode, Hoplolaimus columbus

Feeding and egg-laying of Hoplolaimus columbus were observed on excised alfalfa (cultivar 'DuPuits') root cultures in 1.0% nutrient agar. Feeding was ectoparasitic on cortical cells in the maturation zone of the root. Oocytes were first observed in the anterior ovary of the feeding female 8-9 days after feeding began. Globular secretions emanating from the vagina and vulva preceded migration of the posterior-most oocyte of the anterior gonad into the columella. The egg shell was formed within 8 h, and the egg was laid within 12-24 h. The eggs differed from those of other plant-parasitic nematodes in having a stalk on the distal end. The average time required from egg-laying to hatching was 12 days in water and in alfalfa root cultures.