INSECTS 



379 



escaping the notice of certain predaceous Ichneumon- Flies which 

 lay their own eggs within those of other insects. But it is known 

 that this ingenious device is not always successful. Sharp (in 

 The Cambridge Natural History) makes the following remark 

 about one species: " These eggs are not deposited in any care- 

 ful way, but are discharged at random, simply dropping from 

 the female; the noise caused by the dropping of the eggs of 

 Diapheromera femorata from the trees on which the insects are 

 feeding to the ground is said to resemble the pattering of rain- 

 drops. The eggs of this species often remain till the second year 

 before they hatch." 



The eggs of Locusts 

 and Grasshoppers (Acri- 

 diicUe) are usually de- 

 posited in the ground, a 

 hole being excavated for 

 the purpose. The tip of 

 the abdomen in the female 

 is provided with some 

 hard-tipped rods which 

 serve as spades for doing 

 this work. A number of 

 eggs are laid in the hole 

 (fiV. 808), and with them 



\ o s ]> and closed above. 



is discharged a sort of 



fluid, which subsequently hardens to form a protective case. All 

 these devices are very necessary, as the eggs furnish much- 

 appreciated articles of diet to a number of predaceous insects 

 and other animals. 



In Green Grasshoppers {Locustidce), which are distinguished 

 from the members of the preceding family by the great length 

 of their feelers, the female possesses a long protrusible egg-laying 

 tube or ovipositor, which is used for digging a shelter for the 

 eggs, and afterwards directing them into it. The ground is 

 usually selected for this purpose (fig. 899), but in some cases 

 small twigs are chosen. 



The Crickets (Gryllidce) usually possess ovipositors, which 

 are used for the same purpose as those of the Green Grass- 

 hoppers. The burrowing Mole -Cricket (Gryllotalpa campestris] 

 is an exception to the rule, for in it all the digging is done by 



Fig. 898. Red-legged Locust (Melanoplusfemur-rubrum] 



a, , a, Females laying their eggs ; b, egg-case opened ; c, eggs ; 

 d, hole in the ground being filled with eggs ; e, hole filled with eggs 



