Biology of the Social Wasps of Brazil. 135 



Polyhia scuteUaris it is not easy to discover the males and 

 females. How many times have I not examined the entire 

 contents of the nest without finding any ! In Rio Grande do 

 Sul I several times found females (twelve to fourteen) in the 

 nest of P. scuteUaris, as well as males in considerably larger 

 numbers. The females are not or scarcely larger than the 

 workers ; but the wings, which show a slight brownish 

 sheen, afford a better means of recognition. 



Moreover in this respect the nests exhibit very different 

 conditions, according to the number of the workers. I once 

 examined a rather small nest with only three combs, which 

 nevertheless already contained brood. The number of the 

 workers in this case amounted to only 126. An observation 

 may here also be alluded to which is opposed to what was 

 seen by Janet in connexion with Vespa. The insects brought 

 in by Polyhia scuteUaris are never chewed up into food-balls, 

 but are carried in whole, sometimes more, sometimes less muti- 

 lated, though the wings are always removed. Termites and 

 house-flies constitute the principal quarry, though the latter 

 are seldom captured alive, but are usually carried off when 

 dead or in a half-dead condition. 



In the case also of Polyhia sericea, Oliv., I have frequently 

 seen a new nest commenced in a precisely similar fashion. 

 Once upon a fresh spring morning I observed a swarm that 

 evidently had hibernated without a nest. The wasps, still 

 quite stiff, crawled out from a low bush. The nest had 

 probably been destroyed by inclement weather or by enemies. 

 Among the latter I allude especially to the large " Lagarto " 

 lizard {Twpinamhis teguexin, L.), which is particularly 

 dangerous to the nests of Nectarinia mellificay Sauss., which 

 are always placed pretty low down and are rich in honey. 

 With reference to this it may be remarked that I also met 

 with honey in the nests of Polyhia sericea. 



In the case of the above-named Nectarinia I once observed 

 a nest in autumn which contained about an equal number of 

 males and workers. A large proportion of the latter contained 

 eggs, but one had to regard them as workers on account of 

 the rudimentary receptaculum seminis. It is probable that 

 here also drones are produced from the eggs of workers, and 

 this very circumstance would afford an explanation of the 

 exceptionally large number in the nest referred to. 



In connexion with the differences which have been described 

 in the mode of life of the communities are those which we 

 find in the structure of the nests. In this respect, as regards 

 variety and finish of the edifices, no other region of the earth 

 can compare with Brazil ; for out of the whole of the wasps 



