HYMENOPTERA. 



395 



have a sickle-shaped abdomen. They lay their eggs on the skin 

 of caterpillars, which they attack with the short cutting auger with 

 which they are provided. 



The Cynips, or Gall-insects, are small black or tawny Hymen- 

 optera, the females of which have an auger, rolled up spirally and 

 hidden in a fissure of the abdomen, with which they prick the young 

 shoots of plants. A peculiar liquid which they pour into the hole 

 round the egg they have laid, causes an excrescence to grow, which 

 is called a " gall." The larva is developed in the centre of this gall, 



Fief. 375. Gall insect 

 (Cynips guercusfolii). 



Fig- 37 6 - - ak Galls, produced by 

 Cynips qrtercusfolii. 



Fig- 377. Tnterior 

 of a Gall. 



and transformed into a pupa, and afterwards into a perfect insect, 

 which makes its exit by a hole in the wall of its prison. Fig. 375 

 represents the Cynips of the oak tree (Cynips queraisfolii), and 

 Figs. 376 and 377 the galls it produces. The galls of the rose are 

 hairy, and are sometimes called " Robin's Cushion." The gall-nut, 

 rich in tannin, which is used in the manufacture of ink, is the produce 

 of a foreign Cynips, which lives on an oak found in the East. Apples 

 of Sodom, which travellers bring back from the shores of the Dead 

 Sea, are large galls* full of dry dust and larv?e. 



The Urocerata and the Tenthredinetcz form two tribes of insects, 



Made by Cynips insana. ED. 



