HALF-WINGED INSECTS 



729 



The True Frog-IIOPPERS are small insects about a quarter of 

 an inch long, found among grass and bushes. The fore wings are 

 of rather a stout consistency and uniform in colour (often yellowish), 

 and the hind wings transparent. The lar\-£e are soft grubs, and 

 live in the masses of froth so common in grass and bushes, which are 

 vulgarly known as " cuckoo-spit." 



Passing over several families of small species, we arrive at two 

 which contain many very destructive insects. The Al'PllDES, Plant- 

 LICE, or Smother-flies are the small green or brown winged or 

 wingless insects which frequently cover the shoots of roses and 

 other trees and plants, and exude a sweet stick)' substance, called 

 " honey-dew," very attractive to ants. One species, known as the 

 American Blight, is extremely destructive to apple-trees, patches 

 of a substance resembling white cotton appearing on the bark. 

 Under these patches the bark rots from the attacks of the insects, 

 the pest being very difficult to eradicate. 



Many of the Aphides exhibit the curious phenomenon known 

 as " alternation of generations." The first 

 brood consists of winged males and females ; 



I , but the eggs which the latter lay produce 



exclusively wingless females, or rather sexless 

 creatures capable of la)-ing eggs, and these 

 multiply indefinitely for a time, till perfect 

 males and females are again reproduced. In 

 some cases the winged forms live on the 

 leaves of trees, and the wingless forms at 

 the roots of grass, etc. One of the most 

 destructive of all these insects is the VlNE- 

 APHIS, which was probably introduced into 

 Europe from America, and which threatened 

 at one time almost to destroy the vine in- 

 dustry in France. Wingless sexless forms 

 live and multiply at the roots of vines ; and 

 in summer winged males and females are 

 produced, which fly up, and lay eggs on the 

 leaves; while some of the wingless insects 

 also quit the ground, and form small galls on the vine-leaves. 

 Although very abundant in America, the insect is not nearly so 

 destructive to the plants which it attacks as in Europe. 



Some species of SCALE-INSECTS are almost equally destructive, 

 especially to greenhouse plants. The male is slender and two- 

 winged, but the female is wingless and often legless, and after de- 

 positing her eggs usually dies above them, thus forming a covermg 

 to protect them from injury. Cochineal consists of the bodies of a 

 species of scale-insect which infests the leaves of a cactus m Mex.co. 

 The True Lice are found on various species of mammals, 

 and imbibe their food through a proboscis. The Bird-lice, or 

 BiTIXG-LICE, form a well-defined group by themselves. They are 

 sometimes regarded as forming distinct orders of msects ; but 

 some authors treat the first group as a degraded family of msects 

 allied to the Frog-hoppers, and the second group as an equally 

 degraded and aberra 

 9- 



* 



P*oIo 4» IV P. Dundo, F.Z.S. 



APHIS 



yS sexual luingless form 



Phola iy If. P. Dand,, F.Z.S. 



SCALE-INSECT 



T/ie females die, coi'erifi^ their c^gs 

 ivith their ozt'fi bodies 



nt family allied to the Lace-winged Insects. 



Phtto by IC.P.Danda, F.Z.S. 



SCALE-INSECTS 



S/to^.uin^ their appearance luhen 

 cro-zvdeJ together on a branch 



