318 HALF HOURS WITH INSECTS. [Packard. 



typical example is the Spliex (Fig. 59) whose habits have 

 already been doscribecl. The mud dauber {PelopcBus Jlavi- 

 pes) is a slender form, brightly banded and spotted with 

 yellow, and is found all over the country. Her cells of pel- 

 lets of mud plastered on the wall of a house are common 

 objects known to every school boy. These cells are built 

 of la3-ers of mud of unequal length, the pellets being placed 

 in two rows, diverging from the middle. Tliey are a little 

 over an inch in lengtli and about half as wide, and arc seen 

 in section to be triangular in outline. Tiie larva within 

 spins a brown silken cocoon, after eating up the store of 

 paralyzed spiders, whose remains may often be found tucked 

 away at one end of the cell. Several cells usually occur 

 together, covered over with a common layer of mud. 



Tliis habit of collecting materials for their nests is shown 

 more distinctly in the black Sphex {S. tibialis) which forms 

 its nest in the tunnels previously made by the carpenter bee- 

 in a piece of pine board. In an example described in my 

 "Guide to the Study of Insects," the hole was six inches 

 long, and the oval, cylindrical cocoons were packed loosely, 

 either side by side, where there was room, or in a single 

 row. The interstices between them were filled with bits of 

 rope, which appeared as if they had been bitten in pieces b}' 

 the wasp itself, while the end of the cell was filled for a dis- 

 tance of two inches with a coarse sedge arranged in layers, 

 as if rammed in like gun wadding. 



Another exception to the burrowing habits of the sand 

 wasps is afforded by a Brazilian species of Larrada, which, 

 according to Mr. Bates, builds a nest "composed apparently 

 of the scrapings of the wooll}^ texture of plants ; it is at- 

 tached to a leaf, having a close resemblance to a piece of 

 German tinder, or a piece of sponge." In thus availing 

 itself of the scrapings of the bark of plants, we have a 

 slight anticipation of the paper-making wasps. The wood 

 wasps evince fully as much, if not more, architectui'al skill 



30 



