MASON WASP 



263 



In the lower part of the Mahica woods, towards the 

 river, there is a bed of stiff white clay, which supplies the 

 people of Santarem with material for the raanufacture of 

 coarse pottery and cooking utensils : all the kettles, 

 saucepans, mandioca ovens, coffee-pots, washing- vessels, 

 and so forth, of the poorer classes throughout the country, 

 are made of this same plastic clay, which occurs at short 

 intervals over the whole surface of the Amazons valley, 

 from the neighbourhood of Para to within the Peruvian 

 borders, and forms part of the great Tabatinga marl 

 deposit. To enable the vessels to stand the fire, the bark 

 of a certain tree, called Caraipe, is burnt and mixed with 

 the clay, which gives tenacity to the ware. Caraipe is an 

 article of commerce, being sold, packed in baskets, at the 

 shops in most of the towns. The shallow pits, excavated 

 in the marly soil at Mahica, were very attractive to many 

 kinds of mason bees and wasps, who make use of the clay 

 to build their nests with. I spent many an hour, watching 

 their proceedings ; a short account of the habits of some 

 of these busy creatures may be interesting. 



The most conspicuous was a large yellow and black 

 wasp, with a remarkably long and narrow waist, the 

 Pelopaeus fistularis. It collected the clay in little round 

 pellets, which it carried off, after rolling them into a con- 

 venient shape in its mandibles. It came straight to the 

 pit with a loud hum, and, on alighting, lost not a moment 

 in beginning to work ; finishing the kneading of its little 

 load in two or three minutes. The nest of this species is 

 shaped like a pouch, two inches in length, and is attached 

 to a branch or other projecting object. One of these rest- 

 less artificers once began to build on the handle of a chest 

 in the cabin of my canoe, when we were stationary at a 

 place for several days. It was so intent on its work that 

 it allowed me to inspect the movements of its mouth with 

 a lens whilst it was laying on the mortar. Every fresh 

 pellet was brought in with a triumphant song, which 

 changed to a cheerful busy hum when it alighted and began 

 to work. The little ball of moist clay was laid on the edge 

 of the cell, and then spread out around the circular rim 

 by means of the lower lip guided by the mandibles. The 

 insect placed itself astride over the rim to work, and, on 

 finishing each addition to the structure, took a turn round, 

 patting the sides with its feet inside and out before flying 

 off to gather a fresh pellet. It worked only in sunny 



