—, 


402 THE INSECT WORLD. 
insects of leaden balls contained ‘in cartridges prepared for war. 
M. Milne Edwards read to the Académie des Sciences a short 
Report on these works. 
The insect which had produced the perforations observed in. 
the balls sent to the Crimea in 1857, and which M. Dumeril par-_ 
ticularly studied, was the Sirex, juvencus, and had been taken from 
France in the wood forming the boxes which contained the 
cartridges. In the other case of which we are speaking, that is to 
say, of the cartridges which were sent in 1861 to the Académie 
by Captain Heriot and by M. Bouteille, the perforations had been 
produced by another species. Mr. Milne Edwards, who found the 
insect that had caused this strange damage, had no trouble in. 
recognising it as the Sirex gigas, which, in its larva state, lives, 
in the interior of old trees or pieces of wood, and which after it 
has gone through all its metamorphoses, comes out of its retreat, 
to reproduce its kind. To clear themselves a way, they cut 
away with their mandibles the ligneous substances or other hard 
bodies they meet with on their road. It was in pursuing this 
object that the insects, imprisoned accidentally in the packets of 
cartridges when they were yet only in the larva state, must have | 
attacked the leaden balls, as also the paper and the other matters | 
which they met with on their road, and which opposed their 
passage. M. Bouteille proves, in his Me- 
moir, that M. Dumeril had committed an 
error in saying that the perforating organ 
employed by the Siew to attack the leaden 
balls in the cartridges in the Crimea was 
the auger situated at the extremity of the 
cutting into that part of the wood where 
it is to lay its eggs. M. Bouteille has 
established, in fact, that they were not 
\ only the females which attacked the car- 

abdomen of the female, and intended for | 
Fig. 379.—Larva of aSaw-fy  tridges, but that the males, which have no 
Lenthredo). 1 
( Zenthredo) auger, had occasioned the same damage. 
The Tenthredinete are called “saw-flies,” because the females 
are furnished with a double auger, notched like a saw, with 
which they cut into the vegetables in which they lay their eggs. 


