PSYCHE. 



BIOLOGICAL NOTES ON AiMERICAN GRYLLIDAE. 



BY SAMUEL H. SCUDDER, CAMBRIDGE, MASS. 



Gryllotalpa BOREALIS. 



The burrows of this mole cricket are 

 in the main very superficial, lying just 

 beneath the surface of the soil and run- 

 ning in entirely irregular directions. 

 The insects seem to push their way 

 where the soil yields most readily and 

 take advantage of natural furrows and 

 crevices. The burrows are generally 

 so near the surface that the earth is 

 pushed up above them into ridges 

 which can be easily traced, and when 

 the soil dries after a rain portions of the 

 ridges fall in and expose the binrows. 

 They frequently fork and occasionally 

 turn abruptly downward into blind 

 passages, in which I have failed to find 

 anything. Apparently one insect, or at 

 most a pair, ^ and 9, occupy a single 

 burrow, and males are rarely found 

 nearer together than thirty feet, never 

 apparently nearer than ten or fifteen 

 feet. Rathvon, however, says (Rep. 

 dep. agric, 1S62, 37S) that in a 

 meadow near Lancaster, Penn., over a 

 hundred specimens were once taken in 

 a piece of ground about six feet square. 

 Usually the burrows are just large 

 enough for the crickets to move in (and 

 these insects move backward as readily 



as forwartl) ; but they occasionally 

 enlarge into lateral chambers seldom 

 larger than a pigeon's egg, which 

 enables them to turn around ; and in 

 such chambers the eggs are laid in 

 masses of a hundred or thereabouts 

 adhering to the rootlets of Potentilla 

 and other plants. The eggs are spher- 

 ical, white or almost colorless, and 

 have a diameter of 0.7 mm. The newly 

 hatched larva can leap like a Tridac- 

 tylus. 



TrIDACTYLUS TERMIN'ALIS. 



Messrs. Sanborn and Thaxter once 

 found mature specimens in burrows of 

 Gryllotalpa borealis on the shores of 

 Winter Pond, in Winchester, Mass. I 

 found on visiting the spot that their own 

 burrows were made in gravelly, sandy 

 soil and were very superficial, not more 

 than an inch below the surface. I saw 

 one come out of its burrow, which it 

 did rather slowly, but as soon as its 

 body was three-fourths in sight, it 

 leaped away. They leap in a lively 

 manner to the distance of one or two 

 yards ; and when disturbed move either 

 backward or forward with sudden starts 

 after the manner of Gryllotalpa. The 



