The means which the individual may use in endeavoring to control his insect enemies are many and varied. They may he classed as me chanical methods, farm practices and the applica tion of mate rials commonly called insecti cides.
Mechanical methods.
It is often practicable to hand-pick or dig out insect pests. This is largely prac ticed in coun tries where cheap labor is available. No cheaper and ef fective method has yet been found for com bating borers and many pests (a s cutworms and white grubs) working in gardens and on other small areas. Children have done very effective work in collecting eggs of tent-caterpillars and tussock moths on shade trees. A box-like covering of wire screen or mosquito -netting is often placed over hills of squashes, melons and cucumbers to protect them from the ravages of the striped beetle and stink-bug. Seed-beds of cabbages, radish beds and various choice or rare plants can be thus protected from insects at slight expense. Bushels of young grasshoppers and swarms of small leaf-hoppers are often collected on the western prairies by drawing large iron pans smeared with tar or containing ker osene, and called " hopper-dozers." (Fig. 59.) Thous ands of grape leaf-hoppers can be collected on stinky shields held near while the vines are jarred.
(Fig. 60.) Sticky bands have long been used effec tively to prevent the wingless female moths of canker-worms ascending trees to lay their eggs. (Fig. 61.) For a quarter of a century before the advent of spraying, the principal means em ployed to reduce the numbers of the codling-moth were various kinds of cloth or hay-rope bands around the trunks of the trees to form more attrac tive places for the caterpillars to transform. Large numbers of the caterpillars gather under these bands, where they are easily killed. This effective banding method can now be used with profit to supplement the poison spray when a second brood of the insect occurs. Farmers often use the barrier method to prevent chinch-bugs, cutworms or army worms from marching intoother fields.
Two furrows plowed to gether and a narrow strip o f coal - tar poured along the ridge thus formed, effec tively stop chinch - bugs. (Fig. 62.) To stop army worms a deep furrow is plowed with the perpendic ular side to ward the field to be protected, and post-holes are then dug in the furrow at intervals of a rod or less. The caterpil lars can not readily scale the furrow and so wan der along it, finally dropping into the holes, where they can be killed with kerosene or crushed ; bushels of the worms are often killed by this bar rier method. Some insects may be jarred on sheets or into catchers. (Figs. 63, 64.) Farm practices.
The American farmer who grows field crops mostly, must depend largely on im proved or different methods in growing his crops, or on what may be called farm prac tices, to prevent and control the ravages of insect pests. Often the horticulturist or
gardener can also use these methods to good advantage.
Thorough and frequent cultivation, especi ally in early autumn, discourages and finally effectively controls wireworms and white grubs more than anything yet devised. One rarely sees a well-cultivated orchard seriously infested with canker-worms, as many of the pupa in the soil are thus destroyed. A fre quent rotation of the crops is one of the most effective methods of controlling insects which attack field crops, as corn, clover, wheat, potatoes and similar crops. The in sects are starved out by finding their favorite food-plant replaced by some crop they do not like. Many field crops may suffer for a season or two from wireworms or white grubs if planted in fields, as pastures or old meadows, that have been in sod for several years and are the favorite breed ing grounds of these pests. But thorough cultiva tion of such crops will soon discourage the insects.
Clean culture, or the destroying of weeds and clearing away of rubbish, will often help in the warfare against insect pests. Many insects find favorable hibernating quarters in rubbish, old stone walls, near-by clumps of bushes or forest lands. One fruit-grower has largely eliminated the plum curculio from his peach orchard by planting it away from such favorable hibernating quarters. The removal or burial of old cabbage stumps, old squash or cucumber vines, and other garden refuse, so as to leave the ground clean in the fall, will help much in controlling garden insects, like the cabbage, radish- and onion-maggots, cutworms, and other serious pests. Sometimes an attractive plant is used early in the season as a decoy, to be de stroyed when it has served its purpose and become well infested with the pest. Then the main crop to be protected is planted later and often escapes serious infestation. A strip of mustard or early cabbages may be sown early in spring to attract the hibernated harlequin-bugs, which can then be killed with kerosene before the main crop of cab bage is put out. A strip of wheat sown in August will often attract a large proportion of the autumn brood of the hessian fly. This infested strip can then be plowed under in September, or just before the whole field is prepared for the main crop, which should be delayed in planting as long as local conditions will permit. This "farm practice" method of an early decoy strip and late planting will usually circumvent this serious wheat, barley and rye pest. Gardeners who grow cucurbitaceous vines sometimes plant a strip of early squashes along one side of the field and delay putting out the main crop, so as to at tract many of the striped beetles, stink-bugs and borers to the decoy strip.