32 ON SOME HABITS OF A PEL0P02US, 



On the 4th January, 1880, on resuming my observations, I saw 

 to my surprise ; that two cells of a nest of Pelopceus Icetus which 

 which had been finally closed, and were intact on the preceding 

 day, had been broken open. This nest had been finished for some 

 time, so I was at a loss to account for the re-opening, but the 

 whole was explained when another hornet, Larrada Australis, 

 suddenly emerged from one of these cells. This hornet kept 

 running in and out of these cells in a very restless manner, 

 appearing to snatch a mouthful of something each time it entered, 

 I hastily concluded that it must be devouring the food therein, 

 and fearing to lose the specimen I captured and transferred it to 

 my specimen box ; I place it on the table for inspection, together 

 with a specimen of Pelopceus Icetus. 



More of the species Larrada Australis, came about the nests of 

 Pelopceus laitus that I was watching, and I observed several more 

 of their cells broken open by the Larrada, but I could come 

 to no satisfactory conclusion, as to their real object in pursuing 

 this predaceous course ; until the 18th January, 1880. I then 

 saw one of this species deliberately take possession of a cell of 

 Pelopceus Icetus, on which they were at work. No decided attempt 

 was made by the Pelopceus, to regain possession, although this 

 cell contained its own ovum, and three spiders. Both hornets 

 skirmished about for a time, each seeming afraid of the other, at 

 last Larrada Australis entered the cell, and settled down to its 

 work without further opposition ; the aperture of this cell being 

 much larger than the one made by Larrada Australis itself, 

 admitted of more light, so I determined at the risk of a sting to 

 find out what was going on inside ; I accordingly placed my eye 

 right close to the entrance, and saw that the Larrada was 

 dividing the cell into two portions by erecting a wall of mud ; it 

 then became evident to me that this hornet was playing 

 the part of the Cuckoo, by depositing its own egg in the nest 

 of another species, so that its young might be developed at the 

 expense of the labours of another. After this I examined all the 

 cells which had been taken possession of by this hornet, and as I 

 anticipated, I found in every case the ovum of Larrada Australis ? 



