Pratylenchus convallariae
Seinhorst, 1959
Syn. Pratylenchus pratensis in Slootweg, 1956
(prob.) Tylenchus pratensis in Van Poeteren, 1920; Cobb, 1921
Photo Gallery- Konza Prairie

Measurements (from Seinhorst, 1959)
L = 0.58-0.61 mm; a = 23-27; b = 6-9; c = 17-28; V = 78-81; Stylet = 16-17 um.
L = 0.49-0.58 mm; a = 27-36; b = 5.2-6; c = 20-23; T = 25-51%; Stylet = 15-17 um.

Description (from Seinhorst, 1959)
 Cuticle marked by fine striae, about 1.5 um apart.  Lateral fields with 4 incisures.  Lip region slightly set off from body and bearing 3 annules.  Lateral margins of cephalic framework extending posteriorly for about half a body-annule.  Spear 17 um long.  Dorsal oesophageal gland opening into lumen of the oesophagus about 3 um from spear base.  Excretory duct opening ventrally at level of junction between oesophagus and intestine.  Hemizonid situated just anterior to this opening.  Deirids not seen.  Female tail sometimes bluntly rounded and with striations around the tip as in P. pratensis but mostly more or less split into two irregular lobes.  Phasmids at middle of tail.  The inner two incisures of the lateral field go past the phasmid as in P. penetrans.
 Ovary single, outstretched, with a single row of oocytes.  Spermatheca round.  Uterus short.  Postvulvar uterine sac extending backwards 1.4-2 times the body width at the vulva and about as long as the tail.
 The male does not differ anatomically from the males of P. penetrans.
Type host: Roots of Convallaria majalis.
Type locality: Wassenaar, Netherlands.
Relationships:  The species resembles P. penetrans most closely, in size and form.  It differs from this species in the tail tip being irregularly lobed and having incisures.  The latter are less regular than in P. pratensis from which species P. convallariae is also different in having a spermatheca.  P. convallariae causes lesions in the root cortex of Convallaria majalis; in heavy attacks the lesions may lead to a serious root rot.  The species was also found in sandy soil at Wageningen and Graveland (both in the Netherlands).

Measurements (from Loof, 1960)
L = 389-597 u; a = 20.6-30.4; b = 5.6-7.6; c = 17.1-22.7; V = 75.6-81.2
L = 380-521 u; a = 23.5-33.8; b = 5.1-6.4; c = 17.1-21.5; T = 36-55

Description (from Loof, 1960)
    Body moderately slender; long specimens were found to be more slender than short ones.  Body almost straight when killed by gentle heat.  Annulation of cuticle fine.  Lateral field with 4 incisures, the outer ones weakly crenate, the inner ones amalgamating at about level of phasmid.  Lip region with 3 annules; outer angles rounded.  Labial framework as in P. penetrans.  Stylet knobs high and rather narrow, Hemizonid distinct.
    Female: Ovary with oocytes in single row, except for short zone near anterior end.  Spermatheca round.  Posterior uterine branch a little over one body width long.  Phasmid about middle of tail, rather inconspicuous.  Tail with coarsely, irregularly annulated posterior edge, truncate in most specimens.
    Male: Very similar to that of P. penetrans.  In some specimens the tail tip appeared bifid, in others the bursal edge was slightly irregular immediately before the tail tip.  Bursal edge coarsely crenate.  Testis shorter than vas deferens in the specimens studied the demarcation between these two parts was more distinct than in other species of Pratylenchus.
    Diagnosis: P. convallariae resembles P. pratensis, P. crenatus and P. penetrans.  From pratensis it may be distinguished by the truncate tail and round spermatheca, from the second by the presence of a spermatheca and numerous males, by the weaker body annulation, 4 incisures in lateral field, more anterior position of vulva, and tail shape; from P. penetrans by the annulated tail tip and position of vulva.  This last difference is small, but on examination of 50 females of  both species was found to be highly significant (difference 6 times its standard error).
    Distribution and hosts: P. convallariae is known only from Convallaria, where it causes severe damage (Van Poeteren, 1920).  It has been reported from the Netherlands and from Germany.

Description (from Seinhorst, 1968)
 The stylet is 16-18 um (average 17um).  The distance between vulva and spermatheca is 44% to 66% of that between vulva and anus.  The length of the postvulvar uterine branch is 21% to 25% of the distance between vulva and anus.  There are 16 to 19 (rarely more than 20) rather wide annules on the tail.  The tail tip is coarsely and often irregularly annulated.  It is also often split, the connection between the lateral fields around the tip being shorter than that between the dorsal and ventral side of the animal.