86 



ELEMENTARY ENTOMOLOGY 



cannibals. The eggs are laid in the ground in the fall and hatch 

 the next summer. The males have the best-developed musical 



apparatus of all 

 the orthopteran 

 orchestra. The 

 principal vein, 

 which extends 

 along the base of 

 the wing-cover, 

 is ridged like a 

 file, and on the 

 inner margin of 

 the wing-cover, 

 a short distance 

 from the base, 



FIG. 1 08. Female of Gryllus assimilis, with inner and outer the edge is hard- 

 views of auditory membranes on front tibiae, at c and d pried SO that it 

 (After Marlatt, United States Department of Agriculture) rnav be used as a 



scraper, or rasp. Elevating his wings to an angle of forty-five degrees, 

 and arranging them so that the 

 scraper of one rests on the file 

 of the other, he moves them to 

 set the neighboring wing mem- 

 branes into vibration, thus pro- 

 ducing the shrill call or the 

 faint chirp, according to his 

 mood. 



The tree crickets are quite 

 different from the common 

 black sorts and are arboreal, as 

 their name indicates. They are 

 of a creamy-white or light yel- 

 lowish color, often slightly 

 tinged with green, and the wings FIG. 109. A tree cricket ( CEca /////// s fasti- 

 are transparent. The antennae <"" J ) male and female 



are much longer than the body, 



which is about half an inch long, and the ovipositor is well devel- 

 oped. The wings when at rest are usually held so as to form a long 



