ARTHROPODA 



200 



lice and bark-lice; the Mallophaga, parasitic bird-lice which eat hair and feathers; 

 the Physopoda, or thrips; the Dermaptera or earwigs; the Neuroptera, the Dobson 

 flies, ant-lions, and lace- winged-flies; the Trichoptera or caddice flies, which in the 

 larval stage cements around itself a protecting case made of sand or other particles 

 of matter. 



FIG. 139. 



FIG. 139. Katydid (Cyrtophyllus perspicitlatus), natural size. Photo by Folsom. 



Questions on the figure. How many pairs of appendages are visible in the 

 figure? How many pairs are present ? To what order of insects does the Katydid 

 belong? What are its feeding habits ? What can you find of its development? 



FIG. 140. 



FIG. 140. Periodical Cicada. Natural size. Photo by Folsom. 



Questions on the figure. To which order of insects does Cicada belong? 

 Which -of its habits are most familiar to you? What are its nearest relatives 

 among the insects? 



Order Hemiptera (half -wing}. Hexapoda with an incomplete metamorphosis, 

 and having two pairs of wings, or none. Mouth parts are modified for piercing 

 and sucking. Here are included the true bugs, as the squash bug, chinch bug, bed- 

 bug, the water boatman, etc.; the lice; the plant-lice; the scale insects ; and the 

 cicadas (sometimes called "locusts"). These should not be confused with the 



