Meloidogyne fallax and Nacobbus aberrans
False root‑knot nematodes are soilborne microscopic roundworms that cause galls to form on plant roots, mimicking the symptoms caused by true root‑knot nematodes (Meloidogyne spp.).
They are of particular concern in agriculture as they can affect multiple plant families and may not respond to control methods used to treat true root-knot nematodes.
While much of the documented impact has been observed in large-scale crop production, home gardeners should still be aware of the symptoms, host plants, and strategies for control.
Read on to learn more about false root-knot nematodes.
Here’s what I’ll cover:
What Are False Root-Knot Nematodes?
The two species commonly known as false root-knot nematodes are Nacobbus aberrans and Meloidogyne fallax.
Nacobbus aberrans was first described in the 1930s and later identified on sugar beets in Nebraska in 1949.
Although it is treated as a single species, mounting evidence suggests it should be considered a species complex, a group of closely related but genetically distinct populations.
Unique pathotypes have been documented that exhibit differing host preferences such as beans, potatoes, or sugar beets, and occur across a wide range of habitats.
Its known distribution includes several US states such as Nebraska, Wyoming, Colorado, Utah, Montana, and South Dakota, as well as parts of Mexico and South America.
Meloidogyne fallax, sometimes called the false Columbia root‑knot nematode, was first documented on potatoes in the northern United States in the 1980s.
It has since been reported in regions of Europe, Africa, Oceania, and other parts of the Americas. Like other Meloidogyne species, it affects numerous agricultural crops including tomatoes, carrots, leeks, as well as turf grasses.
Since both species can infect a wide range of plants including many common vegetables and ornamental species they are increasingly relevant to home gardeners, particularly in regions where these pests are spreading or becoming established.
