CHAPTER XXVI 

 THE HOMOPTERA 



The Homoptera is a large group containing insects of many forms, 

 often showing little resemblance to one another. ' They suck sap from 

 plants through a beak, apparently very similar in structure to that al- 

 ready described for the Hemiptera, but it is attached, not to the front but 

 to the hinder part of the under surface of the head which is very closely 

 joined to the prothorax so that the beak frequently appears to arise 

 between the front legs. In some instances where the adults do not feed, 

 this structure is lacking. The wings are often absent but when present 

 are usually held, while at rest, sloping over the body like a house roof. 

 They are of the same thickness and usually, though not always, trans- 

 parent. In this group (except the male scale insects) the metamorphosis 

 is incomplete. These facts may be summarized as follows: 



The Homoptera are sucking insects with the beak (when present) arising 

 from the back part of the under side of the head which is very closely joined 

 to the prothorax. The wings (frequently absent) are of uniform thickness 

 throughout and when not in use are held sloping over the body. The meta- 

 morphosis (except in male scale insects) is incomplete. 



Few groups of insects show as great differences in their members as are 

 found here. The cicadas, often two or three inches in length and with a 

 wing spread of four inches or more, are among the giants of the order, 

 while some of the white flies and scale insects are hardly more than 

 just visible to the eye. Most of the group move about freely, though 

 some locate in one place soon after they hatch and remain there 

 the rest of their lives. In one section the insect produces a protec- 

 tive scale which covers it, and beneath this, degeneration of some 

 parts of the body occurs. 



Many Homoptera secrete a sweet, sticky fluid called honey-dew, 

 often in such quantities when the insects are in abundance, that in falling 

 it makes a noise like fine rain. Striking on leaves, fruit or bark, it adheres 

 and dries, and a blackish fungus grows in it, giving to such places a sooty 

 appearance. This secretion appears to be produced most abundantly by 

 the soft scales, white flies, plant lice, jumping plant lice and some of 

 the tree hoppers. Ants and honey bees feed on the honey-dew and 

 frequently visit the insects producing it, for this food. 



Nine families of Homoptera are generally recognized, but four of 



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