THE RUBY-TAILS. 413 



Now we come to a very remarkable group of Hymenoptera 

 called Chrysididre. This is a Greek word signifying "gilded," 

 and is given to the insects on account of the brilliant colours 

 with which they are adorned. Several species of Chrysididse 

 are inhabitants of our own country, and are popularly known 

 by the name of Euby-tailed Flies. 



If a female Euby-tail be carefully examined, the abdomen 

 will be seen to consist of only three segments, each being of 

 considerable size. Should the specimen be dry, it will not be 

 easy to find out what has become of the missing segments; 

 but if it be fresh, there will be no great difficulty in finding 

 them. If the abdomen be carefully pressed, there will issue 

 from it a long telescopic tube, which will be found to be formed 

 from the other segments. At the end of this tube is the ovi- 

 positor, which is very short and looks much like a sting. It 

 can even be used for defence, and can give a tolerably sharp 

 prick ; but as there is no poison-gland connected with it, no 

 real harm is done. 



The object of this structure is evident. The insect is parasitic, 

 the eggs being deposited in the nests of other insects, generally 

 solitary bees. The egg of the Chrysis is hatched before that of the 

 real owner, and in consec|uence the larva eats up all the food 

 which was prepared for its unintentional host. It will be seen, 

 therefore, that the telescopic ovipositor is needed in order to 

 enable the Chrysis to deposit its egg at the bottom of the nest, 

 and yet to do so without disturbing the work of the insect 

 whose offspring is to be supplanted. 



In the early spring, specimens of the Chrysis may often be 

 found in holes which were originally intended for other insects. 

 Near my house is a park fence which has recently been mended 

 with a number of pine slabs, the bark being still on them. 

 The bark has been pierced by holes, apparently those of the 

 Sirex, and advantage has been taken of them by sundry small 

 solitary bees. One day, while examining the fence, on which 

 the sun was shining brightly, I caught a sudden flash of crimson 

 in one of the holes, and, on carefully cutting away the wood, 

 found a fine Chrysis quite perfect and ready to emerge when 

 the year should be sufficiently advanced. 



On following up the investigation I found great numbers of 

 Ruby-tails similarly situated. They were all curled up after 



