ICHNEUMON FLIES. WASPS. 53 



4. Some, designated by the common name of TEREBRAN'TIA 

 (from the Latin, terebro, I bore), have, in the female, the abdomen 

 terminated by a simple borer, most generally in form of a saw, 

 which they use to deposit their eggs in suitable places. Of this 

 number are the Ichneumon flies, insects which render essential 

 service to agriculture by destroying a great many caterpillars ; 

 the Cynips, which have a small head, and a large, raised up 

 corselet, which gives them the appearance of being hump-backed. 

 The females make excavations in trees for depositing their eggs, 

 and the juices effused at the wounded spot often produce excres- 

 cences named galls. The gall-nut, of which considerable use is 

 made in dyeing black, and in the manufacture of ink, is developed 

 in this manner on the leaves of a species of oak which grows in 

 Asia Minor. 



5. Other hymenop'terae have the abdomen attached to the 

 thorax by a straight peduncle, and in place of the ovipositor there 

 exists in most of the females and most neuters, a retractile sting. 

 They form a group of ACU'LEATES (from the Latin, aculeus, a 

 prickle or sting). The most interesting insects of this division 

 are the wasps, ants, and bees. 



6. Wasps Vespa* are so generally known that it is not neces- 

 sary to describe their form ; but their habits are worthy of atten- 

 tion. These insects, like some other hymenop'terse, live in 

 society. Only the females found new colonies ; in the spring 

 they lay their eggs, from which are derived individuals called 

 workers, who assist their common mother to enlarge the nest and 

 raise the young born afterwards. To construct their nest or 

 vespiary, these insects by aid of their mandibles detach pieces of 

 bark or old wood, which they reduce to a sort of paper-like paste , 

 of this they form the combs or nests, which are generally hori- 

 zontal, suspended by pedicles, and present at the lower edge series 

 of hexagonal cells, serving for the lodgment of the larvae and 

 pupae. These cells are ranged parallel to each other, at regular 

 distances, and are joined together at intervals by little columns 

 which support them (fig. 50) ; the whole is built, sometimes in 

 the open air, sometimes in the hollow of a tree, and some are 

 naked or enclosed in a common envelope, according to the species 

 (Jig- 50). The cells, which vary in number, are sometimes 

 covered and communicate externally by a common aperture. It 

 is only in the beginning of autumn that male wasps are found in 

 the vespiary; the young females make their appearance about 

 the same time. About the month of November the young wasps 

 that have not yet completed their last metamorphosis, are put to 



4. What are gall-nuts ? 



5. What insects arc comprised in the group of Aculeates ? 



6. What are the habits of wasps ? 



