Cockroaches, Locusts, Grasshoppers, and Crickets 161 



much reduced, being nearly lost, and as this cricket crawls rather than 

 leaps, the hind or leaping legs are not so disproportionately larger than the 

 others as in the above-ground crickets. The males make a sharp chirping 

 loud enough to be heard several rods away. The common species, called 

 the northern mole-cricket, Gryllotalpa borealis, has the wing-covers less than 

 half the length of the abdomen, while the wings extend 

 only about one-sixth of an inch beyond them. A less 

 common species, G. Columbia, the long- winged mole- 

 cricket, has the hind wings extending beyond the 

 tip of the abdomen. The mole-crickets like rather 

 damp places near ponds or streams, where they make 

 channels with raised ridges which resemble miniature 

 mole-hills. These "runs" usually end beneath a stone 

 or small stick. The insects are infrequently seen, as 

 they remain mostly underground, only occasionally 

 coming out at night. The female deposits from two 

 hundred to three hundred eggs in masses of from 

 forty to sixty in underground chambers, and the young 

 are about three years in reaching maturity. When 

 present in any region in large numbers mole-crickets FIG. 230. The Porto 



become seriously destructive because of their attacks ? ic ^ , mol e-<jncket, 

 ' bcaptenscus didacty- 



on plant-roots. In Porto Rico a mole-cricket, Scap- lus. (After Barrett; 



teriscus didactylus (Fig. 230), called "changa," dam- natural size.) 



ages tobacco, sugar-cane, and small crops to the value of more than 

 $100,000 annually and is by far the most serious insect 

 pest in the island. 



Much smaller than the true mole-crickets are the 

 pygmy, burrowing crickets of the genus Tridactylus, 

 of which several species occur in the United States. 

 The largest species, T. apicalis (Fig. 231), is about 

 inch long. They resemble the mole-crickets in general 

 body characters, but are more brightly colored, and the 

 fore feet, although broad and flat for digging, differ in 

 being curiously armed at the end with three spurs; hence 



FIG. 231. 'I ridactylus fa e generic name. They can leap amazingly, so that 

 apicahs. (After . 



Lugger; natural size they seem, on jumping, to disappear most mysteriously, 



indicated by line.) the eye not being able to follow them in the air. 



The most aberrant of all the crickets are the tiny flat and broad-bodied 

 species of the genus Myrmecophila, which live as commensals or mess- 

 mates in the nests of ants. They are found only in ants' nests, have no 

 compound eyes, and the hind femora are much swollen and enlarged. 





