A CUNNING USURPER. 485 



one of the many that were formerly included in the genus 

 Odynerus. 



Several species of these insects inhabit India, and Mr. Home 

 has described the habits of three of them, showing, that there are 

 considerable differences in their modes of building. One of 

 them, Rhynchium camaticum, inhabits the interior of small hol- 

 low bamboos. \ nest which Mr. Home found was constructed 

 in a very singular manner, the insect having taken possession 

 of a bamboo winch had been previously occupied by one of 

 the solitary bees, Megachile lanata, and in which two cells 

 had already been formed. The Ehynchium did not try to eject 

 the original occupant, but simply built it in. 



" It first built over the cells of the Megachile a floor, which was 

 constructed of mud, very finely worked, stout at the edges and 

 thinner in the middle. It then left a space empty and made an- 

 other floor, after which it commenced its breeding cells. In these 

 it stored caterpillars of many colours, and it finished off with an 

 empty spare cell, which it covered with a heavy mass of pellets. 

 The clay is kneaded very finely, and, although there are no sides 

 to be made to the cell, the cap is most carefully constructed." 



There seems to be more than instinct in this proceeding. 

 As the Ehvnchium is much slower than the Megachile in under- 

 going its changes, the latter would be developed first, and so 

 break through all the cells of the former in trying to make 

 its escape. So, first the Rhynchium begins by shutting off the 

 Megachile with a strong clay wall, and then, in order to guard 

 against the possibility of one of the insects breaking through 

 this wall, it takes the precaution to leave a clear space, and 

 then to build a second wall, before it proceeds to form its cells. 

 I have noticed that all insects which have to break through 

 obstacles before they reach the open air have sufficient strength 

 to do so, and a little to spare besides. But the amount of strength 

 is not much in excess of the work to be done with it, and there 

 is no insect with which I am acquainted which would not perish 

 before it could break through two obstacles of equal strength. 



I should much like to present the reader with an illus- 

 tration of this remarkable nest, but as the nest, or rather the 

 series of cells, is half as long again as the page, and would not 

 bear reduction, it cannot be done. The colour of the insect 

 is ruddy brown. 



