PARASITES THAT ARE FREE WHEN OLD. 167 



ones. For tins purpose the fly establishes itself upon 

 the back of the caterpillar, and mounted thus, without 

 the caterpillar's suspecting the least in the world the 

 danger that it runs, the fly inserts her larv« to the 

 number of ten or twelve. When she has thus deposited 

 these, the fly goes to seek another caterpillar, like the 

 cuckoo in search of a fresh nest every time that she 

 lays an egg. 



The young flies, left to themselves, pierce the skin of 

 their host, and all take their place at the banquet, says 

 Mons. Barthelemy. 



After three moults the fly is completely developed, it 

 devours the interior of the larvas which has nourished it, 

 pierces the skin, and the dead body of its host, which 

 might have been its tomb, becomes, on the contrary, its 

 cradle. 



While not far off from the remains of its feast, its 



own skin hardens till it becomes a veritable shell, and the 



parasitical insect awakes, furnished with wings, ready 



to recommence, after a minute devoted to love, the circle 



'in which pass the unvarying phases of its evolution. 



The female of the Scotia attacks the larva of the 

 large scarai)86us {Orijctes nasicornis), which is found in 

 tan, and pierces it with its ovipositor at the same time 

 that it deposits an egg in the body of the gigantic larva. 

 The larva which will proceed from the egg will suck up 

 the fluid parts of the Oryctes while on the grass, and the 

 skin of its victim will serve in the spring as a cradle for 

 its transformation into a nymph. 



Scohetes also attack the large oryctes which destroys 

 the cocoa-nut trees of the Seychelles Islands. It is the 

 same with a large species found in IMadagascar. 



