False Root-knot Nematode
Saccate (0.8 to 1.4 mm long and 0.2 to 0.45 mm wide).
Nacobbus dorsalis differs
from N. aberrans
in the number of annules
between vulva and anus (VA = 8-14 in N. dorsalis
compared to VA = 15-24 in
and a more posterior vulval position in the immature females (94-97%
compared to 91-94 %, respectively). Mature N. dorsalis
females are rounder compared
to the spindle-shaped N. aberrans
Posterior of female - vulva and anus (SEM):
Photograph: I. Cid. del Prado
Vermiform and of the same body length as females.
Spicules and gubernaculum.
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
In California, this species of false root knot nematode is found occasionally in Kern, King,
Los Angeles, Monterey, Riverside, and San Luis Obispo counties. Mainly on
plants not of agricultural importance.
in California Nematode Pest Rating System.
Mainly reported from non-agricultural plants, and quite rare.
Mature females penetrate roots, become swollen and sedentary, cause
formation of root galls and enlarged cells.
Eggs are retained in the female body in N. dorsalis.
Life cycle is approximately 48 days at 25 C.
The nematode migrates through plant tissues as a juvenile; it initiates a
gall and becomes sedentary as a young female.
Host Plant Resistance, Non-hosts and Crop Rotation alternatives:
Manzanilla-Lopez, R. H., M. A. Costilla, M. Doucet, J. Franco, R. N. Inserra,
P. S. Lehman, I. Cid del Prado-Vera, R. M. Souza, and K. Evans. 2002. The genus
Nacobbus Thorne & Allen, 1944 (Nematoda:Pratylenchidae):Systematics,
distribution, biology and management. Nematropica 32:149-227.