Control. Commercial growers sometimes use lead arsenate, but the
fruit has to be thoroughly washed; rotenone sprays or dusts are safer for
NARCISSUS BULB FLY (Lampetia equestris).
The fly infests narcissus,
hyacinth, amaryllis, and galtonia and is primarily a grower's problem. I had thought it also a western problem until some neighboring New
Jersey gardeners brought me rotting amaryllis bulbs each containing
a very large, 3/4-inch long, fat, yellowish-white maggot. They said that
whenever they put amaryllis in the garden for the summer the flies,
hairy, yellow and black, about the size of small bumble bees, came around
to lay eggs at the base of leaves or in the neck of bulbs.
The LESSER BULB FLY (Eumerus tuberculatus)
is similar but smaller,
the maggots not over l/2 inch long and occurring several in a bulb. This
species infests onions as well as narcissus and amaryllis.
Control. Standard procedure for growers has been to soak bulbs in hot
water at 110° to 115°F. for 2% hours, but very recently it has been learned
that a 10-minute soaking in heptachlor (at the rate of 1/2 pound to 64
gallons of water) just before planting gives almost complete protection.
It keeps the larvae from entering the bulbs. Aldrin and chlordane are
also effective but require higher dosages and longer treatment.
A gall is an enlargement of plant tissue due to irritation from bacteria, fungi, insects, or other causal factors. Galls formed on red-cedars
by the cedar-apple rust are discussed under Rusts; aphid galls on spruce
have been discussed under Aphids; small galls on chrysanthemum are
mentioned under Midges.
AZALEA LEAF GALL (Exobasidium vacinii).
On azaleas, blueberry, andromeda, rhododendron, and other broad-leaved evergreens the galls
are bladder-shaped enlargements of all or part of a leaf. They are white
or pink and succulent when first formed, later brown and hard. Normally
this is not a serious disease, but in wet seasons and especially in the South,
the number of deformed leaves becomes rather alarming. It seldom pays
to do anything more than remove the galls by hand.
CAMELLIA LEAF GALL (Exobasidium camelliae).
Symptoms are a striking
enlargement and thickening of leaves, which become 4 or more
times the size of normal leaves and very thick and succulent. The upper
surface is nearly normal in color, the lower has a white membrane which
cracks and peels back. There is seldom more than one diseased shoot
on a stem, and it is easier to cut off affected parts than to do protective
spraying with low-lime bordeaux mixture.