INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 59 



HEMIPTERA (Order) 



HALF-WINGED INSECTS 



CICADAS, LEAF-HOPPERS, TREE-HOPPERS, PLANT LICE, SCALE INSECTS, 

 WHITE FLIES AND TRUE BUGS 



This is the sixth largest order in the number of species, and is one of 

 the most destructive orders of insects. There are nearly twenty thou- 

 sand known species. The front wings of the members of one of the 

 suborders are thickened at the base, the tips being membranous and 

 overlapping and appearing like half wings. This peculiarity probably 

 gave rise to the name Hemiptera, which was applied to the whole order, 

 though the majority of the members do not have such wings and many 

 have no wings at all. The mouth-parts are constructed for piercing and 

 sucking and never for chewing. The transformations or metamorphoses 

 are incomplete, the young or nymphs differing from the adults chiefly 

 in the lack of the development of sexual organs. 



The order Hemiptera is usually divided into the three following sub- 

 orders: Homoptera, Heteroptera and Parasita or Anoplura, only the 

 first two of which will be considered. 



HOMOPTERA (Suborder) 



This suborder includes many insects which are quite destructive to 

 plant life. "Whenever wings are present they are held roof-like over the 

 body and may or may not be membranous. The front of the head is 

 bent under the body, so as to touch the bases of the front coxae. In the 

 families, Psyllidce, Aphididce, Coccidce and Aleyrodidce, however, the 

 head is so fused with the thorax that one cannot demonstrate that it 

 touches the coxae. 



The families of this suborder are : 



Fulgoridce (Lantern flies) 



Cicadidce (Cicadas or Harvest flies) 



Cercopidce (Spittle insects) 



MembracidcB (Tree-hoppers) 



Jassidce (Leaf -hoppers) 



Psyllidce (Jumping plant lice) 



Aphididce (Plant lice) 



Coccidce (Scale insects) 



Aleyrodidce (Mealy wings or White flies) 

 As the Fulgoridce and the Cercopidce are of little or no economic 

 importance in California they will not be considered in this work. 



CICADIDM (Family) 



CICADAS 



The cicadas are well-known insects, being commonly called harvest 

 flies or locusts. The proboscis rises plainly from the head; there are 

 three ocelli present ; the males have musical organs ; the feet have three 

 segments and the antennae are very small and bristle-like. The eggs are 

 laid by the female in small twigs, punctures being made by the ovi- 



