ORTHOPTERA 



251 



what like a hand or a foot of a mole ; they are terminated by strong, 

 blade-like teeth, termed the dactyls (Fig. 274). 



Two of the tarsal segments -are blade-like and so situated that 

 they can be moved across the dactyls like the 

 cutting blades of a mowing machine (Fig. 275). 

 Sharpe ('95) states that this organ enables the 

 mole-cricket to cut the small roots it meets in 

 digging its burrows ; but this is doubted by Morse 

 ('20), who believes that the roots are cut by the 

 powerful mandibles. 



The antennas of mole-crickets are much shorter 

 than the body; the hind femora are but little 

 enlarged, not well fitted for jumping; and the 

 ovipositor is not visible externally. The name of 

 the type genus, Gryllotalpa, is from Gryllus, a 

 cricket, and talpa, a mole. 



Two genera of mole-crickets are found in the 

 United States: Gryllotalpa, in which the front 

 tibiee are furnished with four dactyls; and Scap- 

 ienscus, in which each fore tibia bears only two 

 dactyls. Each of these genera is represented in 

 our fauna by several species. 



Our best-known and most widely distributed ^^^-^l^- —Gryllotai. 

 • ^ 77 ,v/7 7 7^ _. 7 /-rv- \ -T^i • pa hexadactyla. 



species IS Gryllotalpa hexadactyla {rig. 274). ihis 



species has been generally known in this country as Gryllotalpa 



horedlis; but this name is now be- 

 lieved to be a synonym. The 

 range of this species extends from 

 British America to the southern 

 part of South America. The 

 length of the body is 20-30 mm. 

 The mole-crickets are not 

 common insects in this country; 

 but occasionally they are found 

 in great numbers in a limited lo- 

 cality. They make burrows in 

 moist places from six to eight 

 inches below the surface of the 

 ground, and feed upon the tender 

 roots of yarious plants, and also 

 on other insects. The eggs are 

 deposited in a neatly constructed 

 subterranean chamber, about the 

 size of a hen's egg. 



Fig. 275. — Front leg of a mole-cricket; 

 A, inner aspect; B, outer aspect; e, 

 ear-slit. (From Sharp.) 



Subfamily TRIDACTYLIN^ 



The Pigmy Mole-Crickets 



The members of this subfamily resemble the mole-crickets in the 

 form of the body and in their burrowing habits; but they are much 



