ORTHOPTERA 87 



wedge tapering toward the head. The young tree crickets are 

 somewhat beneficial, as they feed upon plant-lice, but the adults 

 do considerably more injury by slitting the 

 twigs of cane fruits, fruit trees, cotton, etc., 

 in which their eggs are deposited, and beyond 

 which the twigs usually die. 



One small group of crickets, called mole 

 crickets, are usually found in the ground, 

 burrowing here and there by means of the 

 front tibiae, which form shovels admirable for 

 that purpose. Mole crickets are more abun- 

 dant in the South and Southwest, where they 

 feed upon the roots of plants, but are very 

 rarely injurious. In Porto Rico, however, the 

 changa is the most serious insect pest of the 

 island, annually doing one hundred thousand 

 dollars' worth of damage to the staple crops. 



FIG. no. Eggs of a 



tree cricket (CEcanthus 



nigricornis} 



a, blackberry cane, show- 

 ing egg punctures ; l>, the 

 same split, to show the 

 arrangement of the eggs ; 

 c, egg very much en- 

 larged ; d, its tip still more 

 enlarged. (After Riley) 



Earwigs (Euplexopterd). 



The earwigs are nearly re- FlG , changa (Scapteriscus didacty i us Lat r.) 



lated to the Orthoptera, 



though they are often placed 



in a separate order, Euplex- 



optera, which means " well-folded wing," referring to the wing, 



which is folded lengthwise, like that of the grasshopper, and 



then crosswise. They are small insects, our common species 



A mole cricket which is the most serious insect pest 

 in Porto Rico. (After Barrett) 



