HOUSE CRICKET. 241 



pair of antennce, and to warn the insect of any danger ap- 

 proaching from behind. The female has an ovipositor, or in- 

 strument for depositing the eggs, which in some species is as 

 long as the body. 



The best known English species is the common House 

 Cricket {Aclieta domestica), which is so well known as to need 

 but little description. Still, the reader will find that a careful 

 examination of this insect will be especially interesting and 

 instructive, as it affords an excellent type of the whole family. 

 The peculiar veining, or ' neuration ' as it is scientifically called, 

 of the elytra is very well displayed, this being a very important 

 point in the economy of the insect. 



Every one is familiar with the shrill noise or ' song ' produced 

 by the Cricket. This sound is not uttered from the mouth, 

 but is caused by the action of the elytra on each other. If 

 the reader will examine one of these elytra taken from the 

 male insect, he will see that there is a very strong vein or 

 nervure, starting from a thickened spot almost one-third 

 of the length of the elytra from the base. In the riglit 

 elytron this nervure is marked underneath with a series of 

 notches like those of a file, and this is the instrument which 

 produces the sound. When the wings are closed, the right 

 elytron lies over its fellow, so that its notched underside comes 

 upon the upper part of the corresponding nervure in the left 

 elytron. The elytra being put in rapid vibration, the notched 

 nervure plays against its fellow, and a shrill sound is produced, 

 strengthened by the form of the elytra, which act as sounding- 

 boards. The action of the notched nervure is exactly the same 

 as that of the iron ' rasp ' which used to supply the place of a 

 knocker in old houses. I may as well mention here that the 

 name Acheta is Grreek, and signifies ' shrill-sounding.' 



The whole arrangement of the nervures, indeed, differs in 

 the two sexes ; so that a single elytron is sufficient to tell the 

 entomologist the sex of the insect from which it was taken. 

 In the Mole Cricket, which will presently be described, this 

 peculiarity is of very great value, as it affords almost the only 

 external characteristic by which the male can be distinguished 

 from the female. In both sexes the elytra do not — as they 

 appear to do at a casual glance — merely lie flat on the back. 

 There is a very strong longitudinal nervure rimning from the 



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