THE SAND WASPS. 



497 



almost every case, the caterpillar bears the seeds of death within its body in the shape of 

 tiny white grubs, like very minute grains of rice. These creatures are the young of an 

 Ichneumon-fly (Microgaster glomerdtus), and retain their place within the caterpillar until 

 the time for it to change into the perfect form. They then simultaneously eat their way 

 out of the skin, spin a number of bright yellow silken cocoons, and in process of time change 

 into tiny flies and set out on their destructive mission. The caterpillar never survives 

 their attacks, and is seldom able to move away from the spot whereon it happened to be 

 when the Ichneumons make their escape, the body being enveloped in their yellow cocoons. 



All the Ichneumon-flies may be distinguished by their fussy restless movements, as 

 they run up and down any object on which they may settle, and the continual quivering 

 of their antennae. The two lower figures in the illustration belong to this family, that 

 on the left showing an example of the long ovipositor with which several species are 

 furnished, and the other being given in order to show the wasp-like abdomen and the 

 curled antennae. 



The Ehyssa persuasoria is the largest British Ichneumon, and is parasitic on Urocerus 

 fuvencus, another species of the same genus as that to which the giant Ichneumon 

 belongs. The larva on which it preys bores deep holes in fir-trees, and, in consequence, 

 the Ehyssa may be seen running up and down the trunks in search of some spot where 

 the ovipositor may be introduced so as to lodge in the hidden larva. So deeply does 

 the insect contrive to force its weapon into the wood, that it sometimes is unable to 

 withdraw it, and may be seen hanging dead and dry to the tree in which it has buried the 

 ovipositor too firmly. 



PASSING by several families be- 

 longing to this group, we must briefly 

 mention the beautiful EUBY-TAIL 

 FLIES, or CUCKOO FLIES, or Chry- 

 sididae, so plentiful in summer about 

 old walls and similar localities. 

 These are distinguished by the fact 

 that, in the females, the last seg- 

 ments of the abdomen are formed 

 into a telescopic tube, which can 

 be projected or retracted at plea- 

 sure, and is furnished with a 

 minute sting. These are, per- 

 haps, the most brilliant in colour 

 of any British insect, and are 

 veritable humming birds of the 

 insect tribes, their bodies literally 

 flashing with ruby, sapphire, and 

 emerald, as they flit restlessly in 

 the sunbeams. They are parasitic 

 insects, and haunt the walls for 

 the purpose of depositing their 

 eggs in the larvae of sundry soli- 

 tary bees and wasps. 



IN the next great division of Hymenopterous insects, the ovipositor of the female is 

 changed into a sharply pointed weapon, popularly called a sting, and connected with a 

 gland in which ?.s secreted a poison closely analogous to that which envenoms a serpent's 

 tooth. These are again divided into the Insectivora, or those which have fore-wings not 

 folded, and the larvae solitary and feeding on other insects ; the Sodales, where the fore- 

 wings are not folded, and the larvae are social ; and the Diploptera, where the fore-wings 

 are folded, and the larvae (in the social species) inclosed in separate cells. 



. The first of these sections comprises all those curious and interesting insects known 

 popularly by the names of Sand Wasps and Wood Wasps. These creatures are in the 

 3. ICK 



Crabro cribrarius. 



PMlanthus tridngulum. 



