74 



aphis can inflict is quite trivial, but when this is multiplied by the 

 large numbers which may exist, the e\ul reaches large proportions. 

 Sometimes the aphides can be eradicated without great difficulty, 

 sometimes they defy all efforts with any known insecticide. They 

 all have a beak with which they puncture tiie plant upon which 

 they have settled and having thus made an outlet for the sap they 

 feed upon it. This drain upon the plant weakens it, and when the 

 leaves are attacked they may swell, crumple or become covered 

 with galls so that their natural function is hindered or pi"evented, 

 and the plant suffers if it does not perish. The aphides are emi- 

 nently plant parasites, and almost all species are infested by one 

 or more species of aphis, which are often peculiar to it. 



The " honey dew" found, it may be to a disagreeable extent, 

 about plants infested w'ith aphides, comes from the repletion ofthe 

 insects. They suck up the sap ofthe plant on which they have 

 located until they are full and more. In many species there are 

 on the upper, hind parts of the abdomen two little tubes which 

 serve as outlets for the sap, and this is distributed as a transparent, 

 milky or colored liquid of a sweet, sticky nature, much liked by 

 ants and some other insects. .This " honey dew" is sometimes 

 produced to an astonishing extent, considering the very small size 

 of the insects which produce it. Last August it was literally 

 showered down from some ofthe elms in Burlington, so that the 

 fences, walks or whatever was beneath them were bespattered 

 thickly with the sticky ffuid which turning black as it was exposed 

 to the sun and air and became exceedingly unpleasant. As will be 

 shown later the metamorphoses ofthe aphides and their allies are 

 much more numerous than is usual, even among insects, and the 

 differences are sometimes so great that it is difficult to recognize 

 the same insect under its varied disguises. Not only are- there dif- 

 ferent broods, each different from the others, but within the lim- 

 its of each brood the changes from the egg to the adult are often 

 great. So, too, in their reproduction they vary. One brood lays 

 eggs, which perhaps develop into forms unlike the parent, all of 

 which produce living 30ung, there being no sexual distinctions, 

 and in course of time from these, or their descendants, come true 

 males and females which jxiir and again hermaphrodite forms ap- 

 pear tor a series of generations, and so on. Fortunately for man 

 the aphides are weak and slow moving Insects, and are easily 

 seized by their numerous enemies. 



