ORTHOPTERA 



53 



are harmless. Roaches in a house do little real destruction, 

 but spoil food by running over it and eating parts of it. 

 They often seriously injure 

 book-bindings by gnawing 

 them. They hide in cracks 

 and crevices and in holes 

 made for plumbing. In old 

 houses it is next to impos- 

 sible to be entirely rid of 

 them. Many roach destroy- 

 ers, usually in the form 

 of powders, are sold and 

 some are said to be effi- 

 cient. Old houses, even if 

 entirely freed from roaches, 

 will always be likely to be 

 soon reinfested from neigh- 

 boring houses. 



There are several spe- 

 cies of roaches but all that 

 live in houses are similar 

 in habits and appearance. 

 Both winged and wingless 

 forms may always be found. 



42. Phasmidae and 

 Mantidae. Two very pe- 

 culiarly formed groups of 

 insects are the Phasmids 

 or " Walking-sticks " and 

 the Mantids or "Rear-horses." The former are elongated, 

 have very long and slender legs and antennae and are 

 wingless.* They are usually green or brown in color and 

 * Many tropical species have wings. 



FIG. 33. Types of Orthoptera. 



1, 2, 3, and 4, Roaches (Blattida;) ; 

 5 and 6, Tree-crickets; 7, Mole-cricket; 

 8, 9, Ground-crickets (all Gryllidas). 



