Heterodera trifolii Goffart, 1932
Synonyms: Heterodera shachtii var. trifolii (Goffart,
Heterodera trifolii trifolii (Goffart, 1944)
Heterodera (Heterodera) trifolii (Skarbilovich, 1959)
Lip region set off from neck,
rounded, with 6 annules.
Stylet well-developed with knobs slightly backward
glands less well-developed than in
infective second-stage juvenile.
pore posterior to esophago-intestinal valve.
The is hemizonid
6 to 14 annules in from of the excretory
pore (Norton 1967).
Testis single; spicule
curved, blades with truncated
or oblique lips, not appearing bidentate. Gubernaculum
simple, proximity arcuate. According to Norton (1967),
the spicules appear to be bidentate.
Second-stage Juvenile: Head offset,
with 4 annules, head skeleton heavily sclerotized.
Stylet robust, anterior surfaces of knobs concave.
Dorsal gland duct opening 5-9 Âµm posterior to spear
glands, particularly the subventrals,
well-developed, extending ventrally or ventro-laterally
well posterior to esophago-intestinal valve.
Tail conoid, tapering uniformly to a finely rounded
terminus. Posterior half of tail hyaline. Phasmids
usually obscure, located near middle of tail.
esophageal bulb rounded, with distinct valve.
Ovaries paired, greatly extended and nearly filling
the body cavity of the adult female.
Vulval cone covered with a gelatinous matrix
containing as many as 200 eggs (Thorne, 1961).
Surface of female and newly-formed cysts typically
encrusted with a material termed "subcrystalline
layer." Transitional stage between white female and
brown cyst distinctly yellow. The yellow color varies
with the strain of the host plant, being constant in
females developing on any one host strain (Norton, 1967).
Cyst: Brown to dark brown containing
a few to several hundred eggs, eventually becoming
detached from the roots to lie in the soil where the
protected eggs may remain viable for several years.
Identification of species of Heterodera is
based largely on the cone top structures, including
fenestra (thin-walled areas around the gonopore of the
cyst), vulval slit length, underbridge and
bullae (see Mulvey, 1972).
H. trifolii can be separated from H.
trifolii by its heavier and more strongly
pigmented underbridge, with bifurcate ends, its greater
fenestral length, and shorter vulva-anus distance.
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:
Cosmopolitan species, occurring widely throughout northern
Europe and Spain, Italy, southern France, Soviet Union, Canada,
U.S., Israel, India, Australia and New Zealand.
in California Nematode Pest Rating System.
Feeding site establishment and development
typical of genus.
Attacks legumes (86 species in 9 families). Several forms of clover are
reported as hosts of H. trifolii in New Zealand (Mercer and Woodfield, 1986). A species thought
to be H. trifolii is a serious pest of carnation in Italy
and in glasshouses in southern France.
There may be several pathotypes of H. trifolii.
Root leachates stimulate hatching and attract juveniles to
Eggs are produced early by the adult white female; the first
eggs are laid in a gelatinous matrix adhering to the vulval cone.
Most eggs, however, mature within the extensive gonad as the cyst
develops, and are retained within the brown cyst.
First-stage juveniles molt to the second, infective stage
within the egg. Hatching of the eggs retained within the
protective cyst, however, occurs progressively over a period of
years in the soil in response to moisture and root leachates.
Emergence from juveniles in cysts may be seasonal and influenced
by diapause and temperature. Juveniles emerge over a relatively
wide range of temperatures (4.2 to 31.4 C), with 17.2 C being
optimum (Oostenbrink, 1967).
Multiple infections may kill root tip.
Freckman & Chapman (1972) showed that, with mixed
infestations of H. trifolii and M.
syncytia and giant cells occurred side-by-side with no
Methods for controlling other species of Heterodera
are generally applicable for this species, although seldom
is known in some white clovers (Kuiper,
1960) and soybeans (Mankau & Linford, 1956).
Endo & Schaeffer (1967) discovered that applications of
the chemical azauracil consistently arrested further development
of early third-stage juveniles in red clover under greenhouse
Nematicides: In France, also in greenhouses,
applied in November and February at doses of 45, 7.5 or 19 kg
a.i./ha, resulted in reduced infestation and increased flower
yield in carnation nurseries (Cuany, 1970).