. The animans and man; an elementary textbook of zoology and human physiology. vapor of bisulphide of car-FIG. 92. San Jose scale bon is a very effective insecticide,insect removed from The bisulphide of carbon can be its waxen under cover- •, i , T -j • j j ing. (Much enlarged.) b°U§ht aS a ll(lUld m drUS St°reS and a little of it poured into an open saucer which can be placed in a closed closet, or bin ortrunk or even in a tight room. It volatilizes rapidly and thefumes are deadly. As the fumes are heavier than air thesaucer should be placed in the upper part of the closet orbin. On
. The animans and man; an elementary textbook of zoology and human physiology. vapor of bisulphide of car-FIG. 92. San Jose scale bon is a very effective insecticide,insect removed from The bisulphide of carbon can be its waxen under cover- •, i , T -j • j j ing. (Much enlarged.) b°U§ht aS a ll(lUld m drUS St°reS and a little of it poured into an open saucer which can be placed in a closed closet, or bin ortrunk or even in a tight room. It volatilizes rapidly and thefumes are deadly. As the fumes are heavier than air thesaucer should be placed in the upper part of the closet orbin. One dram of the liquid will suffice for each cubicfoot of space in the receptacle. The vapor is inflammableand explosive and cannot be used where it can come intocontact with fire. This remedy is very convenient andeffective for clothes moths. For some kinds of insects simple methods of killing byattracting them to light or to poisoned food can be used. Preventive remedies for insects such as the screening ofwindows, the covering of special plants with netting, or the. FIGHTING INSECT PESTS 187 encircling of tree trunks with bands of some sticky substanceto prevent the crawling up of wingless insects have theirplace in insect fighting. There still remains one other class of the so-called arti-ficial remedies to be mentioned. They are really, howevernatural remedies. These are all those included under thegeneral term of clean farming and high cultivation. Theresult of their use is to make the plant better fitted to with-stand the attacks of their insect enemies. In nature almostall plants have to sustain more or less severe insect is naturally the weakest plants that succumb first. Whereman has gathered together many plant individuals of onekind and has by that very act invited all the kinds of insectsthat normally feed on these kinds of plants to come andfeast, he is, we might say, morally bound to protect his plantwards from the too serious appetites of their g
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Keywords: ., bookcentury1900, bookd, booksubjectphysiology, booksubjectzoology
