Ditylenchus dipsaci
(Kühn, 1857) Filipjev, 1936
Bulb and Stem Nematode
Photo Gallery- Utah alfalfa
Anguillula dipsaci Kühn, 1857
Anguillula dipsaci (Kühn) Gerv. et. v. Ben., 1859
Tylenchus dipsaci (Kühn) Bastian, 1865
Anguillula devastatrix Kühn, 1868
Anguillula secale Nitschke, 1868
Anguillula putrefaciens Kühn, 1877
Tylenchus havensteini Kühn, 1881
Tylenchus hyacinthi Prillieux, 1881
Tylenchus alii Beijerinck, 1883
Tylenchus devastatrix Ritzema Bos, 1888
Ditylenchus phloxidis Kirianova, 1951
Ditylenchus fragariae Kirianova, 1951
Anguillula dipsaci var. dipsaci Steiner and Scott, 1935
Anguillula dipsaci var. communis Steiner and Scott, 1935

Female:  1.0-1.3 mm; a = 36-40; b = 6.5-7.1; c = 14-18; V = 80
Male:  1.0-1.3 mm; a = 37-41; b = 6.5-7.3; c = 11-15; T = 65-72

Body marked by transverse striae, about 1 u apart, which are easily visible under the oil immersion at any point on the body.  Lateral field marked by four incisures.  Deirids usually visible near base of neck.  Hemizonid adjacent to excretory pore, about six annules wide.  Phasmids rarely visible and then only from a dorsal or ventral view on favorable specimens.  Amphid apertures on apices of lateral lips, where they appear as minute refractive dots which can be seen only from a face view.  Spear with strongly developed knobs from which protrudor muscles lead to the well-sclerotized cephalic framework.  Basal esophageal bulb with the usual three prominent and two inconspicuous, gland nuclei.  Intestine connected to esophageal lumen by a very small valvular apparatus.
     Ovary outstretched, sometimes reaching to median esophageal bulb, but more often near basal bulb, rarely with one or two flexures.  Oocytes lie largely in tandem and develop into eggs which are two to three times as long as the body diameter.  Rudimentary posterior uterine branch present, extending about half-way back to anus.  Vulva-anus distance equal to 1 3/4 to 2 1/4 times tail length.  Teminus always acute.
     Testis outstretched, with spermatocytes arranged in single file except for a short region of multiplication.  From a perfectly  lateral view the spicula exhibit a sclerotized pattern that apparently is characteristic of the species, but the proper angle of observation is so difficult to obtain that the pattern is rarely of taxonomic value.  Bursa rising opposite proximal ends of spicula and extending about three-fourths the length of the tail.  Lateral incisures ending in a pattern as illustrated.

Type host:  Dipsacus fullonum L., fuller's teasel

Dimensions (from various sources):
    Females:  L = 1.0 - 2.2 mm, a = 36-64, b = 6.5-12, c = 11-20, c' = 3-6, V = 76-86, stylet = 10-13 um
    Males:  L = 1.0-1.9 mm, a = 37-74, b = 6-15,c = 12-19, stylet = 10-12 um.

    Description:  Body straight or almost so when relaxed.  Lateral field with four incisures.  Head unstriated, continuous with adjacent body part.  Stylet cone about half of stylet length, knobs rounded.  Median esophageal bulb muscular, with thickenings of lumen walls about 4-5 um long.  Basal bulb offset or overlapping intestine for a few micrometers.  Excretory pore opposite posterior part of isthmus or glandular bulb.  Postvulval part of uterine sac about half of vulva-anus distance long or slightly more.  Male cloacal alae envelop about three-quarters of tail length.  Spicules 23-28 um long.  Tail of both sexes conical, always pointed.

Distribution and Economic Importance
    Ditylenchus dipsaci is one of the most devastating plant parasitic nematodes on a wide range of crops.  In heavy infestation crop losses of 60-80% are not unusual; e.g., in Italy up to 60% of onion seedlings died before reaching the transplanting stage and for garlic crop losses of about 50% were recorded from Italy and more than 90% from France and Poland.  In Morocco D. dipsaci was found in 79% of seed stocks of Vicia faba examined (Schreiber, 1977).
(Description- Manual of Agricultural Nematology, Nickle,ed.  1991)