Rev 09/13/2023
Tylenchina Tylenchoidea Pratylenchidae Nacobbinae
Nacobbus dorsalis Thorne & Allen, 1944
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 N. aberrans) 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 females.
Posterior of female - vulva and anus (SEM):
Photograph: I. Cid. del Prado
Vermiform and of the same body length as females.
Caudal alae peloderan.
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.
D-rated pest 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.
Ecophysiological Parameters:
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.
Resistance
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.