VESPARI^. 149 



'builds its cells of clay, and, according to Waterhouse, "the 

 work is exceedingly beautiful and true." Another species, 

 .according to Smith, makes its nest of sandy loam, the exterior 

 being so hard that a saw used in opening one of its sides was 

 blunted. 



The larva of Vespa arenaria is long and cylindrical, not 

 so much curved as in Polistes. Its position in its cell corre- 

 sponds to its form, as the cell is longer and narrower than that 

 of Polistes. Each segment of the body is posteriorly some- 

 what thickened, as is the lateral (pleural) ridge of the body. 

 The tip of the abdomen is rather blunt, the last steruite be- 

 ing large and transverse. The pupa is provided with a single 

 tubercle on the vertex, where there are two in the Crabron- 

 idce and Sphegidce. 



By the time the nest of V. arenaria is large enough to 

 contain ten full-grown larvae, and has about fourteen cells in 

 all, being about an inch in diameter, the occupants of the two 

 or three central cells will have changed to pupae, and one wasp 

 will have been excluded. 



In a nest of the same species two inches in diameter, there 

 were a second brood of larvae. The outer row of cells were 

 occupied by pupae, while the central ones, emptied of the first 

 brood, were filled with a second brood of larvae. Evidently as 

 soon as an imago leaves its cell, the female deposits an egg 

 therein, as very minute larvae were found occupying cells next 

 to those containing large full-grown larvae. 



In comparing a number of pupae from a large nest, they 

 will be found to be in all stages of perfection, from the 

 larva which has ceased feeding, and is preparing to transform, 

 to the imago, still veiled by its thin subimago pellicle. It is dif- 

 ficult to draw lines between these stages. Also when com- 

 pared closely side by side, it is difficult, if not impossible to find 

 any two pupae just alike, the development proceeding very un- 

 equally. Thus the limbs may be more perfect than the antennae, 

 or certain parts may be less perfect in some than in others, while 

 the limbs may be more highly colored like the imago. 



Like the bees, Vespa suffers from numerous parasites, includ- 

 ing Rhipiphorous paradoxus, which is a beetle allied to Stylops, 

 and Lebia (Dromius) linearis. The larva of Volucella is said 



