Biology Reference
In-Depth Information
Paratylenchus (
Gracilacus
) anceps On Cali-
fornia-laurel.
Paratylenchus dianthus
Carnation Pin Nema-
tode
. First reported on carnation in 1955 in
Maryland, now well distributed through the
Northeast.
Paratylenchus elachistus On Boehmeria.
Paratylenchus (
Gracilacus
) epacris
California
Sessile Nematode
. Associated with a decline of
black-walnut trees in California.
Paratylenchus hamatus
Celery Pin Nematode
,
Fig Pin Nematode
. On azalea, bean, boxwood,
celery, chrysanthemum, clover, corn, fig, gera-
nium, gladiolus, turf grasses, hemlock, holly,
horse-radish, iris, oak, onion, parsley, peach,
pieris, pine, mountain-pink, prune, rose, soybean,
strawberry, and tomato. This species is responsi-
ble for celery losses in New England, plants being
stunted and chlorotic, and with decline of fig in
California, symptoms being chlorosis and leaf
drop and undersized fruit. On mint it has caused
one-third reduction in growth. The nematodes
can be starved out of celery fields by a 2-year
rotation with lettuce and spinach.
Paratylenchus micoletzkyi On marigold.
Paratylenchus macrophallus On mint.
Paratylenchus projectus Reported from Mary-
land in 1955 on pasture grasses, also found on
roots of alfalfa, bean, clover, corn, spruce, and
soybean. A serious decline of celery and parsley
in New Jersey was attributed to this species.
Preplanting fumigation has produced a striking
growth response.
Paratylenchus penetrans On snapdragon.
Meadow Nematode
. On corn, grasses, cereals,
asparagus, avocado, citrus, collinsia, dogwood,
peanut, pieris, pine, pineapple, potato, soybean,
strawberry, and tomato. Unsightly lesions are
formed on peanut shells, and the nematode sur-
vives through curing. Preplanting soil fumigation
has increased yield.
Pratylenchus coffeae (
P. musicola
) Associated
with strawberry black root and decline,
in
Arkansas.
Pratylenchus crenatus Associated with many
kinds of nursery plants.
Pratylenchus fallax Lesion nematode on grass.
Pratylenchus hexincisus Described from corn
roots, Maryland.
Pratylenchus minyus On pear and grape, in
California. Also, on filaree.
Pratylenchus musicola On banana, fig, olive,
and walnut.
Pratylenchus nannus Lesions nematode; On
zinnia.
Pratylenchus negelectus Lesion nematode on
potato.
Pratylenchus penetrans
Cobb's Meadow
Nematode
. Associated with decline in alfalfa,
amaranth, apple, arborvitae, azalea, bean, black-
berry, blueberry, boxelder, cabbage, carrot,
cedar, celeriac, celery, cherry, chrysan themum,
clover, corn, cucumber, eggplant, fern, garden
balsam, gayfeather, gladiolus, grass, hemlock,
holly, horseradish, lettuce, lily, maple, mock-
orange, onion, parsnip, peach, pear, peony, pep-
per, pieris, pine, mountain-pink, phlox, plum,
peach, pear, potato, raspberry, rose, safflower,
sequoia, soybean, spinach, spirea, strawberry,
sweet potato, tobacco, tomato, turnip, zinnia,
and yarrow. This species is distributed throughout
the United States. Apples have necrotic black or
amber spots on white rootlets; roots may be
stunted and distorted; tree vigor is reduced; leaves
are small. The disease has been called “little leaf”
and “rosette.” The nematodes invade cortex only;
secondary fungi may play a part in symptoms.
Control measures include root dips and soil fumi-
gation, hot-water treatment for strawberry stock
plants, and removal of all old roots on lilies before
forcing. Marigolds produce a chemical toxic to
nematodes and can be used in rotations.
Pratylenchus
Pratylenchidae. Lesion nematodes, sometimes
called root-lesion or meadow nematodes, widely
distributed migratory endoparasites; males and
females wormlike, small, 0.3 to 0.9 mm, with
short stylet. Conspicuous necrotic spots are
formed on roots, and eggs are deposited in root
tissues or in soil. Feeding punctures afford
entrance to pathogenic microorganisms.
Pratylenchus brachyurus (
P. leiocephalus
)
Godfrey's Meadow Nematode
,
Smooth-Headed
