84 HYMENOPTERA 



CHAP. 



constructive efforts. In the British Museum collection there is 

 a nest said to be that of the Japanese hornet, V. japonica. This 

 is completely covered by a paper envelope, and has apparently" 

 only a single small orifice for ingress and egress. In the same 

 collection there is a nest from Bahia (believed to be that of 

 a social wasp, though of what species is unknown), the outer 

 wall of which is apparently formed entirely of earth, and is a 

 quarter or half an inch thick : the comb inside appears also to 

 be formed of clay, the whole forming an elaborate construction 

 in pottery. One is tempted to believe it may prove to be the 

 production of a social Eumenid. 



Habits of Social Wasps. We have already briefly noticed 

 the way in which a colony of wasps is founded, but some further 

 particulars as to the mode in which the society is increased and 

 developed may be mentioned. The queen-wasp makes at first only 

 a very small group of three or four incomplete cells ; each cell is at 

 first circular, or nearly so, and moreover is of smaller diameter than 

 it will afterwards be. In each of the first three or four incomplete 

 cells an egg is laid, and more cells are commenced ; but as the 

 eggs soon hatch and produce larvae that grow rapidly, the labours 

 of the queen-wasp are chiefly directed to feeding the young. At 

 first she supplies them with saccharine matter, which she pro- 

 cures from flowers or fruits, but soon gives them a stronger diet 

 of insect meat. This is procured by chasing living Insects of 

 various kinds. Some species of wasps prefer particular kinds of 

 Insects, and the hornet is said to be very fond of the honey-bee, but 

 as a rule Diptera are the prey selected. When an Insect has been 

 secured, the hard and innutritions parts are bitten off, and the 

 succulent parts, more especially the thorax which contains chiefly 

 muscular tissue, are reduced to a pulp by means of the mandibles; 

 this is offered to the larvae, which are said to stretch out their 

 heads to the mother to receive the food, after the manner of nest- 

 ling birds. When a larva is full grown it spins a cocoon in the 

 cell and changes to a pupa. It is said by some entomologists 

 that the queen-wasp closes the cell for the purpose of the larval 

 metamorphosis; but -this is contradicted by others, and is prob- 

 ably erroneous. In about a month, or a little less, from the 

 time of deposition of the egg, the perfect Insect is ready for issue, 

 and almost immediately after leaving its cell it assists in the 

 work that is going on for the development of the society. The 



