ABSTRACT

Nematodes hatch from eggs and grow by molting the old cuticle. Nearly all species have four juvenile stages followed by the adult stage. The adults are larger than juveniles, and in some groups, females may be swollen, primarily for increased egg production. Most nematodes are observed easily under a dissecting microscope at 40-60× magnification. The detailed observations needed to identify nematode species, however, must usually be made at much higher magnifications (600-1000×). The egg-to-egg life cycle of plant-parasitic nematodes takes a few weeks to more than a year, depending on nematode

Concept Box

species, plant host status, and environmental conditions, especially soil temperature. Some bacteria-feeding nematodes can complete their life cycle in as little as 4 days.