﻿154 [December, 



altogether. The stored larva? had all been eaten, their heads alone 

 remaining, just as when eaten by the wasp grub. The larva then spun 

 a cocoon, which 1 know to be typical of G. ignita. This was the only 

 occasion on which I had a feeding larva of G ignita, and the rapidity 

 with which it fed up astonished me. None of my C. neglecta or biden- 

 tata fed up so rapidly ; but the warm sunny wall on which O. parietum 

 had built her nest may partly account for this, my larvae of the other 

 two species having been kept comparatively cool. 



G. neglecta begins to emerge from the pupa state at the same time 

 as O. spinipes, namely, about the middle of May ; and, by the first 

 week in June, all of both species have emerged. On examining a 

 bank colonised by O. spinipes at this period, the cocoons of the previous 

 year are found empty ; but, if the day be dull, G. neglecta will often be 

 found hiding away in the empty cocoons of O. spinipes, and usually a 

 pair together. When the sun is out, 0. spinipes is busy constructing 

 her canals and granular tubes, and G. neglecta is actively running and 

 flying about the burrows. G, bidentata, however, is not to be seen ; 

 and, on closer examination, it will be found that of this parasite the 

 cocoon of the previous year still contains the perfect insect, which does 

 not emerge until the last of the spinipes brood are coming out, nearly 

 three weeks later than G. neglecta. I have not seen the egg of the 

 latter, and do not know how or where it is laid ; but it supplants that 

 of O. spinipes, as, a few days after the mother wasp has closed her cell, 

 stored with green grubs, it contains a young larva of G. neglecta busily 

 eating that store, and no trace remains of the egg or larva of the 

 Odynerus. Early in July, the larvse of O. spinipes and G. neglecta are 

 to be found full-fed, and spinning their cocoons. As the season ad- 

 vances, the later stored cells appear to escape the attack of G. neglecta ; 

 for, in the middle of July, whilst 0. spinipes is still busy in storing, 

 there are comparatively few specimens of G. neglecta to be seen. On 

 the other hand, G. bidentata is now abundant, though its oviposition 

 has hardly begun. Towards the end of July, 0. spinipes and G. neg- 

 lecta are represented only by odd specimens, which have survived the 

 mass of their brethren, though G. bidentata is still to be found some- 

 what plentifully. 



C. bidentata, when about to deposit her eggs, searches for a full- 

 grown larva of 0. spinipes, at, or immediately after, the period of 

 spinning. O. spinipes, in the completion of her burrow, fills up the 

 mouth with clay long before the most accessible cells can contain full- 

 grown larvse ; but it happens, that, in a large proportion of cases 



