400 



THE SAND WASPS. 



TheJtTiyssapersuasor/'a is the largest European Ichneumon, and is parasitic on Urocerus 

 juvencus, 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 Rhyssa 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 belonging to this 

 group, we must briefly mention the beautiful 

 RUBY-TAIL FLIES, or CUCKOO PLIES, so plentiful 

 in old walls and similar localities. These are 

 distinguished by the fact that, in the females, 

 the last segments of the abdomen are formed into 

 a telescopic tube, which can be projected or 

 retracted at pleasure, and is furnished with a 

 minute sting. These are, perhaps, the most brill- 

 iant in color of any European insect, and are 

 veritable humming-birds of the insect tribes, their 

 bodies literally Hashing with ruby, sapphire, and 

 emerald, as they nit restlessly in the sunbeams. 

 They are parasitic insects, and haunt the walls for 

 the purpose of depositing their eggs in the larva 

 of sundry solitary bees and wasps. 



Orabro cnbr&riut. 



Philaiithus tridngulum. 



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 is 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 larvse solitary and feeding on other insects ; the Sodales, where the fore-wings are not 

 folded, and the larvse 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 habit 

 of making burrows into the ground or in posts, and placing therein their eggs, together with 

 the bodies of other insects which are destined to serve as food for the future progeny. Spiders 

 are sometimes captured and immured for this purpose. In many instances the captured 

 insects are stung to death before they are placed in the burrow, but it is often found that they 

 only receive a wound sufficient to paralyze them, so that they lead a semi-torpid life until 

 they are killed and eaten by the young grub. Two of these Sand Wasps are given in the 

 illustration. That on the left is one of the wood-borers, drilling its burrow into posts, 

 palings, and similar substances, and feeds its young with the larvae of one of the leaf-rolling 

 caterpillars that lives in the oak, and is scientifically known by the name of Tortrix chlordna. 

 It also employs for this purpose several two-winged insects. One species of these burrowing 

 wasps prefers the well-known cuckoo-spit insect for this purpose (Aphrophora spumdria), 

 pulling it out of its frothy bed by means of its long legs. 



The right-hand figure represents a species that is in the habit of provisioning its burrow 

 with the hive-bee, which it contrives to master in spite of the formidable weapon possessed by 

 its victim, and then murders or paralyzes by means of its sting. M. Latreille mentioned that 

 he saw from fifty to sixty of these insects busily engaged in burrowing into a sandbank not 

 more than forty yards long ; and as each female lays five or six eggs, and deposits a bee with 

 each egg, the havoc made among the hives is by no means inconsiderable. 



Iff the accompanying illustration is shown a Brazilian species, belonging to a genus 

 which is represented in Europe by more than twenty species. In these insects the legs are 



