THE HYMENOPTERA. 37 



ones being invariably held captive by the workers until the 

 rest have emerged, when they are all allowed to fly away 

 and form fresh colonies as in the last species. 



Family FORMICID^E. 



Atta antarctica (Plate III., fig. 5 £ , 5a $, 5b, larva). 



This is another very abundant species, found occasion- 

 ally amongst rotten wood in very large communities. Its 

 larva, which is represented at Fig. 5b, does not form any 

 cocoon, the pupa being quite naked and defenceless. It is 

 a beautiful little object when examined with a microscope 

 of moderate power. The annual migration of the winged 

 males and females of this species usually takes place on a 

 hot day in the last week of March, at which time I have 

 observed the air throughout a day's journey absolutely 

 swarming with these little insects. Many specimens are 

 captured in the spiders' webs, while the logs, fences, and 

 ground are covered with ants in the proportion of about ten 

 males to one female. At other seasons of the year the 

 winged individuals of Atta antarctica are seldom observed. 



Family CHALCIDID/E. 



Pteromalus, sp. (?) (Plate III., fig. 9). 



This little insect was reared, in company with thirteen 

 others of the same species, from a pupa of Eurigaster 

 marginatns, which had been procured from a larva of 

 CEceticus omnivorus, and is consequently a true hyperpara- 

 site. 1 Its curious habits will be better understood by the 

 reader after perusal of the life-histories of those two 

 insects, which I have given on pages 60 and 74. The 

 method by which the females of the Hymenoptera whose 

 larvae are parasitic on insects inhabiting other insects, 



1 Hyperparasite is an animal parasitic in a parasite. 



