About 2000 species of plants worldwide are susceptible to infection by root-knot nematodes and they cause approximately 5% of global crop loss.

Four Meloidogyne species (M. javanica, M. arenaria, M. incognita, and M. hapla) are major pests worldwide, with another seven being important on a local basis.

[4] If root-knot nematodes become established in deep-rooted, perennial crops, control is difficult and options are limited.

[8] Vegetable crops grown in warm climates can experience severe losses from root-knot nematodes, and are often routinely treated with a chemical nematicide.

Root-knot nematode damage results in poor growth, a decline in quality and yield of the crop and reduced resistance to other stresses (e.g. drought, other diseases).

[8] However, with changing farming systems, in a disease complex or weakened by other factors, nematode damage is likely to be associated with other problems.

[15] Concomitant with giant cell formation, the surrounding root tissue gives rise to a gall in which the developing juvenile is embedded.

[20] As the gelatinous matrix ages, it becomes tanned, turning from a sticky, colourless jelly to an orange-brown substance which appears layered.

[23] Embryogenesis has also been studied, and the stages of development are easily identifiable with a phase contrast microscope following preparation of an egg mass squash.

Preceded by induced changes in eggshell permeability, hatching may involve physical and/or enzymatic processes in plant-parasitic nematodes.

[24] Cyst nematodes, such as Globodera rostochiensis, may require a specific signal from the root exudates of the host to trigger hatching.

Root-knot nematodes are generally unaffected by the presence of a host, but hatch freely at the appropriate temperature when water is available.