PLANT-SUCKING INSECTS. 127 



using their long hind legs as oars, and thus they dart on any drowning fly that 

 happens to attract their notice. 



The Water-Scorpion (Nepa), an inhabitant of every pool, procures its 

 food upon the stems of submerged plants, or creeps in search of it about the 

 bottom of the pond. This insect is able to inflict a very painful wound if 

 seized incautiously, by means of its strong well-armed beak. 



PLANT-SUCKING INSECTS. ORDER HOMOPTERA.* 



As the Hemiptera were obviously designed to obtain their food 

 by imbibing the juices of dead or of living animals, it can be no 

 matter of surprise to find races of insects much more numerous 

 and important, appointed to feed upon the sap of plants, and 

 that by means of a mouth of a very similar construction. 



The Homopterous Insects, or Plant-suckers, as they have 

 been named, are furnished with four large wings, all of which are 

 transparent and but loosely veined. By means of these they fly 

 from plant to plant, the juices of which seem to be specially 

 appropriated to their use. Such are 



The Tree-hoppers (Cicada], some of them celebrated for their noisy 

 music. The Cicadas pass their lives upon trees or shrubs, upon the sap of 

 which they live. 



The Plant-Lice (Aphides) are small Homopterous insects. They abound 

 in every garden, living on trees and 

 plants in countless multitudes ; indeed, 

 the fecundity of these creatures seems 

 absolutely boundless. It has been cal- 

 culated that if a male Aphis were to 

 live to see his progeny of the fifth gene- 

 ration gathered around him, he would 

 find himself the great -great -grand- 

 father of nine billions nine hundred 

 and four millions of Aphides ; or, in 

 other words, of a family about fifty times 

 more numerous than all the human in- 

 habitants of this globe. With such a 

 fact before us, we leave our readers 

 to judge what might be the result of 

 their undisturbed multiplication. In 

 the course of a few months, even these 

 apparently despicable plant-lice would FIG. 131. LIME-TREE APHIS. 



become a plague as terrible as any with ( The lines Wlder **fe sh tlie ******* 

 which the world has been visited. For- 

 tunately, even here, the balance between increase and destruction is held with 

 an unwavering hand, so that when we notice the innumerable enemies by 



* ofj.bs, homos, simitar ; Trrtyov, pteron, a iving. 



