82 INSECT ARTIZANS AND THEIR WORK 



the clay or mud it needs for its building. In most 

 species of this genus the large cells are formed one 

 against another, in number varying from ten to 

 fifty, and the whole are consolidated into one 

 mass by plastering further mud or clay into the 

 intervening spaces and rounding the composite 

 structure off. It stores the cells with small spiders, 

 and appears to kill these outright by its sting. 

 When the first of the series is dropped into the 

 cell the egg is laid on it, so that the wasp grub 

 begins to feed on the least fresh of its food, and 

 has to work through the whole series before de- 

 composition begins, though one might suppose 

 this would not take long in a fireplace. Spirifex 

 on an average allows eight spiders to each grub, 

 and these are consumed in about ten days. 



Some of these Sceliphrons have learned to disguise 

 their carefully constructed nests. Thus, an Indian 

 species (S. madraspatanus), that comes into houses 

 and decorates walls and furniture with its nests, 

 appears to be desirous of meriting the name of 

 Mud-dauber, for after the nest is complete as a 

 comfortable habitation for the grubs, she some- 

 times gives a few artistic touches in the shape of 

 radiating streaks of mud, which make it look as 

 though a handful of mud had been thrown against 

 the wall and had splashed. There are only from 

 four to six cells in this nest, and each cell as a rule 

 contains a score of spiders. 



An Australian species {Sceliphron Icetus), whose 

 habits are very similar, adds to the finished nest a 



