Florida Agricultural Experiment Station


sects, represented by caterpillars, grasshoppers, and beetles,
have jaws for chewing and they eat holes in plants or consume
all of the tissue. The sucking insects, represented by true
bugs, moths, butterflies, flies, and thrips, have mouth-parts
which form a piercing and sucking tube while the crop acts as
a pump. These insects use only the juices of the plants for food.

 INDIRECT METHODS OF COMBATING INSECTS
 Ravages of insects may be controlled by either direct or
indirect methods. Direct methods include the application of
insecticides or poison baits, hand-picking and collecting in pans,
traps, or special appliances. Indirect methods refer to cultural
methods; the use of trap crops, and the protection of the
enemies of insects. As an ounce of prevention is worth a
pound of cure, a few precautionary measures taken at the right
time may forestall outbreaks of insects which it would be more
expensive to fight by direct measures.
 CULTURAL METHODS
 Frequently a slight change in the method of growing a
crop will forestall a serious outbreak of some insect. These
modifications of farm practice may be beneficial to the soil
aside from giving protection against insects. For instance, in
many cases, as soon as a crop is harvested the land should be
plowed for the next crop, turning under the refuse in which
insects may propagate. This will conserve the moisture, add
humus to the soil, and stop the breeding of insect pests by
burying many of them. Many insects spend the quiescent or
pupal stage in the ground. If the land is plowed and har-
rowed, most of these insects will be either crushed outright,
left on the surface where birds or other enemies can pick them
up, have their pupal cells broken, causing the insect to die from
exposure to the elements, or they will be buried so deeply that
emergence is impossible.
 A cover crop should be grown on truck land during the
summer; a crop being chosen which will not harbor the same
pests that infested the crop which has gone before, and, espe-
cially, different from those of the crop which is to follow. If
the land is permitted to grow grass and weeds during the sum-
mer it gets thoroly stocked with cutworms, white grubs, and a
great variety of other undesirable inhabitants.
 Rotation of crops is as important from the standpoint of
insect control as from that of the maintenance of soil fertility.