232 



ORTHOPTERA 



I tried to chase one of them up to a corner where on a wall 

 a large cockroach-eating spider stood motionless looking out for 

 his prey; the cockroach would rush away from me in the 

 greatest fear, but as soon as it came within a foot of its mortal 

 foe nothing would force it onwards, but back it would double, 

 facing all the danger from me rather than advance nearer to its 

 natural enemy." To this we may add that. cockroaches are the 

 natural prey of the fossorial Hymenoptera of the group Ampuli- 



FIG. 127. Nocticola simoni. A, male ; A ]t tegmen and rudiment of wing ; A?, front 

 of head ; B, female. The cerci are broken, in B the right one is restored in out- 

 line. (After Bolivar.) 



cides, and that these wasps sometimes enter houses in search of 

 the Insects. 



We have already noticed the considerable difference that 

 exists in many cases between the sexes of the same species. 

 This is sometimes carried to such an extent that nothing but 

 direct observation could make us believe that the males and 

 females are of one kin. Fig. 118 (p. 220) shows a case of this 

 kind. Though the young as a rule are excessively similar to the 

 adults, yet this is by no means invariably the case. In some 

 of the more amply winged forms, such as Blabera, the young is 

 about as different from the adult as the female of Heteroyamia, 



