Canadian Orthoptera. 399 



with four wedge-like pieces, placed in pairs above and 

 below, and opening and shutting opposite to each other. 

 "When about to deposit her eggs, the female forces these 

 wedges into the earth, these being opened and withdrawn 

 enlarge the opening ; the operation being repeated until a 

 hole is formed large and deep enough to admit nearly the 

 whole of the body. The eggs of locusts are generally de- 

 posited in the ground ; those of the Rocky Mountain locust 

 Caloptenus spretus, according to Prof. Riley, are voided in a 

 glistening and glutinous fluid which holds them together 

 and binds them into a cylindrical pod. 



Prof. Thomas states that he has obtained the eggs of 

 Caloptenus femur-rubrum in rotten wood, in which they were 

 placed without any apparent regularity, and without any 

 connection by any glutinous secretion. 



The sounds made by locusts are produced in two ways. 

 First, by rubbing the hind thighs up and down on the wing- 

 covers; and second, by snapping together the edges of the 

 wings and wing-covers during flight. 



Our Canadian locusts fall into two sub-families, Acridince 

 and Tetigince. To the first belong all the species in which 

 the pronotum (upper surface of thorax) extends only to the 

 base of the wing-covers. This group contains the greater 

 number of our species. To the second belong a small group 

 of species in which the wing-covers are aborted, appearing 

 as small pads, while the pronotum extends as far as, or 

 past, the extremity of the abdomen. 



As regards the time of appearance of our locusts, there is 

 a constant succession of species from early spring until late 

 in the fall. A few species (Tetix) hibernate as imago or 

 perfect insects, a few others as larvae, and some as pupae, 

 but the greater number pass the winter in the egg, not 

 attaining the perfect condition until August or September. 



The first to appear are the species of Tetix, which having 

 hibernated in the adult form, may be found as soon as the 

 snow has melted. About the same time, specimens of 

 Tragocephala infuscata, and its variety viridifasciata in the 

 larval condition, make their appearance, attaining the per- 

 fect form by the middle or end of May ; and with them 



