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         Dolichodorus Cobb, 1914


The genus Dolichodorus was erected by Cobb ( 1914) when he named D. heterocephalus from fresh water at Silver Springs, Florida and Douglas Lake, Michigan.
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Morphology and Anatomy:


Large, slender nematodes with cylindroid bodies.  

No secondary sexual dimorphism, sexually reproducing.  

Cuticle distinctly annulated, lateral field with three incisures (Neodolichodorus is distinuished by having four incisures)..  

Labial region distinctly off-set and annulated (rarely smooth).  Labial sclerotization strong, with very thick basal plate and thick arches.                                                            

Stylet long (50 to 160 �m), strong, cone longer than shaft.

Esophagus with amalgamated pro-metacorpus, short isthmus and pyriform glandular region not overlapping the intestine.  

Lateral field with three incisures, areolated.

Amphid apertures small slits laterally or dorso-ventrally directed.  

No deirids.

Females:  Tail rounded to hemispherical with spike-like extension, rarely elongate-conoid

Females with two genital branches, columned uterus with four rows of cells; vagina very heavily sclerotized.


Males: Caudal alae are wing-like and tri-lobed.  Spicules most generally with prominent flanges.  Gubernaculum apparently protruding.  

Diagnostic characteristics of species

Important morphological diagnostic characters for species of Dolichodorus include stylet length, position of the excretory pore in relation to the median bulb and nerve ring, male tail sharacteristics, including shapes and sizes of caudal alae, spicules and gubernaculum, and female tail shape.
Drawings from Gagarin and Nguyen, 2015.

Body size range for the species of this genus in the database - Click:

Key to the species of Dolichodorus

From Geraert (2011), Jimenez Guirado et al. (2007) and Esquivel et al. (2017)


Subfamily Dolichodorinae



Lateral field with 3 incisures



Lateral field with 4 incisures


1a  Lip region flattened 2
1b  Lip region rounded 7
2a  Excretory pore anterior to median bulb D. pulvinus 
2b  Excretory pore posterior to median bulb 3
2c  Excretory pore opposite median bulb 5
3a  Female tail 62-86 μm D. costaricensis 
3b  Female tail > 100 μm 4
4a  Female stylet length 87-90 μm, spicules length 44 μm  D. kishansinghi 
4b  Female stylet length 77-80 μm, spicules length 63-68 μm D.orientalis 
5a  Female c� < 3 D. nigeriensis 
5b  Female c� = 1-2; L>2 mm 6
6a  L = 2.1-2.5 mm; stylet length = 105-117 μm D. profundus 
6b  L = 2.6-3.6 mm;  stylet length = 132-162 μm D. silvestris 
7a  Excretory pore opposite median bulb 8
7b  Excretory pore opposite isthmus 11
7c  Excretory pore opposite basal bulb D. similis 
8a  Cuticle anterior and posterior to vulva with deep grooves   D. miradvulvus 
8b  Cuticle anterior and posterior to vulva without deep grooves  9
9a  Excretory pore opposite anterior region of median bulb; female tail tapering smoothly to a relatively short attenuated posterior part D. pellegrini 
9b  Excretory pore opposite posterior region of median bulb; female tail tapering abruptly 10
10a  Female tail = 49-92 μm;  stylet length = 90-110 μm D. heterocephalus 
10b  Female tail = 72-122 μm;  stylet length = 78-106 μm D. mediterraneus 
11a  Stylet length = 114-129 μm  D. cobbi 
11b  Stylet length < 105 μm  12
12a  L = 1.3-1.9 mm D. minor 
12b  L > 2mm (but D 13
13a  Stylet length = 62-76 μm  D. aestuarius 
13b  Stylet length > 79 μm 14
14a  Female tail = 50-64 μm, tapering abruptly to an acuminate, often spicate, terminus D. marylandicus
14b  Female tail = 60-145 μm  15
15a  Female tail tapering gradually from anus to terminus  D. longicaudatus
15b  Female tail narroring suddenly at one third to half its length 16
16a  L = 2.5 -3.5 mm;  male spicule length 48-67 μm D. aquaticus
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Currently 19 species described for the genus, mainly from wet, sandy or well-aggregated soil locations with adequate pore space for the activity of these large nematodes (Golden, 1958; Chow and Taylor, 1978; Robbins, 1982; Doucet, 1985; Golden et al., 1986; Jimenez Guirado et al., 2007; Silva et al., 2008a, b; Jagdale et al., 2013; Gagarin and Nguyen, 2015; Esquivel et al., 2017)

In a two-year study of the vertical distribution of nematodes in a crop rotation system in Zimbabwe (Ferris, 1969), several hundred soil samples collected up to a depth of 20 cm were negative for presence of any Dolichodorus specimens. However, in a single soil sample collected in wet sandy soil almost at the level of the water table (about 200 cm) round the roots of a Julbernardia globiflora tree in a neighboring the rotation experiment, a few specimens of Dolichodorus were found (Ferris, unpublished). 

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Economic Importance:

D-rated pest in California Nematode Pest Rating System, except for Dolichodorus heterocephalus which is A-rated..

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 Nematodes of the Dolichodoridae are obligate migratory ectoparasites of plant roots. Root tips have been reported as feeding sites reulting in root-tip curvature and discrete galls and elargement of nuclei in cells at the feeding site (Paracer et al., 1967).

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For an extensive host range list for this genus, click
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Life Cycle:

For Ecophysiological Parameters for this genus, click 


Apart from the studies on D. heterocephalus, there has been no work on the life history attributes of nematodes in the genus.  Interestingly, monoxenic tissue culture techniques have been described which might facilitate such studies (Paracer et al., 1967).

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Feeding of D. miradvulvus at roots of the aquatic plant Anubias nana, can result in complete destruction of the root system (Smart and Khuong, 1984, 1985; Smart and Nguyen, 1991).

The damage caused by D. heterocephalus on a range of plants, including celery, garden balsam and sweet corn, planted in the moist sandy soils are well documented (Christie, 1952; Tarjan et al., 1952; Perry, 1953; Paracer et al., 1967).

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Andrassy, I. 1976.  Evolution as a basis for the systematization of nematodes....

Andrassy, I. 2007. Free-living nematodes of Hungary II.  Hungarian Natural History Museum, Budapest. 496p.

Chow, F.H., Taylor, A.L. 1978. Dolichodorus aestuarius n. sp. (Nematoda: Dolichodoridae). Journal of Nematology 10:201-204.

Christie, J. R. 1952. Some new nematodes of critical importance to Florida growers. Proceedings Soil Science Society of Florida 12:30-39.

Doucet, M.E. 1981. Description de Dolichodorus longicaudatus n. sp. et Neodolichodorus leiocephalus n. sp.(Nematoda: Tylenchida). Revue Nematologie.

Doucet, M.E. 1985. Description de Dolichodorus aquaticus n. sp. (Nematoda: Dolichodoridae). Nematologica 31:143-150.

Esquivel, A., Ferris, H., Cid del Prado, I., Subbotin, S.A. 2017. Dolichodorus costaricensis n. sp. (Tylenchida: Dolichodoridae): a new awl nematode species from the Central Pacific region of Costa Rica. Nematropica 47:143-154.

Gagarin, V.G. Nguyen, V.T. 2015. Dolichodorus orientalis sp. n. (Nematoda, Tylenchida) from mangroves of Vietnam. Zoologichesky Zhurnal 94:303-310.

Geraert, E. 2011. The Dolichodoridae of the World. Academia Press, Gent. 520p.

Germani, G. 1990. Descriptions of Dolichodorus pellegrini sp. n. Nematoda, Dolichodoridae) and Xiphinema fagesi sp. n. (Nematoda, Dorylaimidae) from New Caledonia. Nematologica 36:73-80.

Gillespie, W.H., RE Adams 1962. - An awl nematode Dolichodorus silvestris n. sp. from West Virginia. Nematologica 8:93-98.

Golden, A.M. 1958. Dolichodorus similis (Dolichodorinae), a new species of plant nematode. Proceedings of the Helminthological Society of Washington.

Golden, A.M., ZA Handoo, EJ Wehunt . 1986. Description of Dolichodorus cobbi n. sp.(Nematoda: Dolichodoridae) with morphometrics and lectotype designation of D. heterocephalus Cobb, 1914.  Journal of Nematology 18: 556-562.

Jairajpuri, M.S., Rahmani, S.A. 1977. Dolichodorus kishansinghi n. sp.(Nematoda: Dolichodoridae). Indian Journal of Nematology 7:183-185.

Jimenez Guirado, D., Murillo Navarro, J.M., Liebanas, G., Landa, B.B., Castillo, P. 2007. Morphological and molecular characterization of a new awl nematode, Dolichodorus mediterraneus sp. n. (Nematoda: Dolichodoridae) from Spain. Nematology 9:189-199.

Khan, E., Seshadri, A. R., Weischer, B., & Mathen, K. 1971. Five new nematode species associated with coconut in Kerala, India. Indian Journal of Nematology, 1: 116-127. (Dolichodorus pulvinus described)

Lewis, S.A. 1980. Morphology of a new species of Dolichodorus from Zoysia and observations on the identity of Dolichodorus heterocephalus. Journal of Nematology 12:229.

Lewis, S.A., Golden, A.M. 1981. Description and SEM observations of Dolichodorus marylandicus n. sp. with a key to species of Dolichodorus. Journal of Nematology 13: 128-135.

Loof, P.A.A. and Sharma, R.V. 1975. Dolichodorus minor n. sp. (Nematoda: Dolichodoridae) with a key to the genus Dolichodorus. Revista Theobroma, CEPEC, Itabuna, Brasil 5(4):35-41.

Lopez, R. 1994. Morfologia de Dolichodorus minor (Nemata: Dolichodoridae) asociada al cacao en el sureste de Costa Rica. Agronomia Costarricense 18:87-92.

Luc, M. 1960. Dolichodorus profundus n. sp. (Nematoda-Tylenchida). Nematologica 5:1-6.

Luc, M. Souchaud, B. 1989. Liste Des Types Dans La Collection Nationale De Nematodes Du Sol Et Parasites Des Plantes, Au Museum National D'Histoire Naturelle, Paris. Nematologica.  (Dolichodorus aquaticus Doucet, 1986. Nematologica, 31: 143-150. 

Luc & Dalmasso, 1971. Annls Zool. Ecol. anim., 3: 97-101.( Dolichodorus cassati) (cassati later transferred to Neodolichodorus)

Luc, M., Caveness, F.E. 1963. Dolichodorus nigeriensis n. sp. (Nematoda Dolichodoridae). Proceedings of the Helmithological Society of Washington 30:297-299.

Luc, M., Coomans, A., Sarr, E. 1987. Redescription of Neodolichodorus rostrulatus (Siddiqi, 1976) Siddiqi, 1977 (Nematoda: Tylenchina). Revue de Nematologie, 1987 .

Luc & Fortuner, 1987.  Rev. Nematol. 10(2):177-181.

Paracer, S. M., M. Waseem, and B. M. Zuckerman. 1967. The biology and pathogenicity of the awl nematode, Dolichodorus heterocephalus.Nematologica 13:517-524.

Robbins, R.T. 1982. Description of Dolichodorus grandaspicatus n.sp. (Nematoda: Dolichodoridae). Journal of Nematology 14:507-511.

Perry, V. G. 1953. The awl nematode, Dolichodorus heterocephalus, a devastating plant parasite. Proceedings of the Helminthological Society of Washington 20:21-27.


Smart, G.C., Khoung, N.B. 1985. Dolichodorus miradvulvus n. sp. (Nematoda, Tylenchida) with a key to the species. Journal of Nematology 17:29-37.

Smart G. C., and K. B. Nguyen. 1991. Sting and awl nematodes. Pp. 627-668 in Nickle, W. R. (ed.). Manual of Agricultural Nematology. New York: Marcel Dekker Inc.,

Tarjan, A. C., B. F. Lownsbery, and W. D. Hawley.1952. Pathogenicity of some plant-parasitic nematodes from Florida soils. I. The effect of Dolichodorus heterocephalus Cobb on celery.
Phytopathology 42:131-132.


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Copyright © 1999 by Howard Ferris.
Revised: December 10, 2019.