400 THE SAND WASPS. 
The Rhyssa persuasoria 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 
Rusy-TaiL Fires, or Cuckoo Fiiks, 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 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 larva 
of sundry solitary bees and wasps. 


Crabro cribrarius. Philanthus 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 larvee solitary and feeding on other insects; the Soddles, where the fore-wings are not 
folded, and the larvee are social ; and the Dipl6ptera, where the fore-wings are folded, and the 
larvee (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 larvee of one of the leaf-rolling 
caterpillars that lives in the oak, and is scientifically known by the name of Tortriz chlorana. 
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 (Aphréphora spumaria), 
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. 
In 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 
