CELERY—CELERY DISEASES 
negro-bug and a thrips. Most conspicu- 
ous of all is the parsley caterpillar, 
which works also on carrots, caroway, 
fennel and other plants of the same 
family—-a naked caterpillar nearly two 
inches long, green or yellow in color, 
with transverse black bands, and spotted 
with yellow. When disturbed, the larva 
protrudes a Y-shaped yellow horn, from 
which emanates a sickening odor, pre- 
sumably distasteful to birds and other 
enemies. The adult is the common black, 
parsley swallow-tail butterfly, a beautiful 
velvet black butterfly having long swal- 
low-tails, and marked by rows of yellow 
spots. 
Control of these insects will depend 
on their feeding habits. Grasshoppers 
should be killed by Criddle mixture, 
which is poisoned and slightly salted 
horse manure. Flea beetles may be driv- 
en away or killed by arsenate of lead, 
while the plants are small, that being the 
time when most injury is done. Cut 
worms like poisoned bran, made by mix- 
ing thoroughly, one pound of Paris green 
with fifty pounds of dry bran and then 
moistening it with a little molasses and 
water. The zebra caterpillar can be 
usually hand-picked profitably, as well as 
the parsley caterpillar. The plant lice 
and negro bugs should respond to a spray- 
ing with strong tobacco tea or with one 
of the nicotine extracts. This is true 
also of the thrips. 
The leaf hoppers will be driven away 
by such a spray, but they will return 
after it evaporates. For the latter, a reg- 
ular practice of clean culture, and the 
burning of all rubbish, after cold weather 
has set in, will gradually get rid of them, 
especially if this treatment be extended 
over a wide area. Many noxious insects 
winter in rubbish, fallen leaves, along 
hedges, etc. 
R. H. Perri, 
Entomologist of Mich. Exp. Sta. 
CELERY DISEASES 
Bad Seed 
There is scarcely a more vital question 
in celery growing than that of the qual- 
ity of seed used. Seed that is of a bad 
strain though true to varietal name, may 
767 
inflict losses of hundreds or thousands of 
dollars on large growers. Hollow celery, 
or that otherwise useless, according to 
present knowledge is very often due to 
the bad seed. 
Black Root 
Found on plants in seed beds. 
Damping Off 
This trouble is caused by a fungus 
which follows careless watering while 
the plants are very small, attacks the 
seedlings at the point where they emerge 
from the soil, causing them to decay at 
this point. This disease may be avoid- 
ed by starting the plants in trays, and 
subwatering them by setting the trays 
in a shallow trough containing about 1 
inch of water, allowing the water to en- 
ter through the drainage holes in the 
bottom of the tray. In this way the sur- 
face of the soil will remain slightly dry, 
while the roots of the plants receive 
plenty of moisture. Where it is imprac- 
ticable to apply subwatering methods it 
will be necessary to water very carefully 
and to avoid extremes of drought and 
moisture. It is best to prevent too rapid 
evaporation by partial shading with lath 
screens. 
Early Leaf Blight 
Cercospora apti 
Plants may develop this disease in the 
seed bed, and it is most prevalent in early 
summer. 
Control 
Keep young plants coated with 4-4-50 
Bordeaux mixture, later using the non- 
staining ammoniacal copper carbonate 
solution. Well-drained, half-shaded fields 
seem to suffer less than others. 
Heart Rot 
Heart rot is a very destructive decay 
of the inner, or heart, portions of the cel- 
ery plant after blanching has begun. The 
inner parts rot very suddenly, emit a 
penetrating odor and the market value 
of the affected celery is destroyed. 
The decayed parts are teeming with 
motile bacteria to which this form of 
decay has been attributed. The heart rot 
prevails too in very hot, steamy weather, 
but preventive measures are about all 
