32 Insect Architecture. 



burrowers into the ground, and stock their nests with flies oi 

 some kind. 



Another species of this large genus, Crcibro luteipalpis, is 

 fond of making its burrows in the mortar of old walls, pre- 

 ferring those spots where nails have been drawn, making the 

 process of burrowing easier for the insect. It is not un- 

 common in the outskirts of London. All gardeners, espe- 

 cially those who cultivate roses, ought to encourage this 

 very little insect, and welcome its presence, for it pro- 

 visions its nest with the aphides, or green blight, which 

 infect the rose-trees, and which have destroyed so many 

 promising plants. 



The female, which is the larger of the two sexes, measures 

 only three lines in length. The colour is shining black, and 

 the head is rather squared. 



Among other burrowing species of this genus we may 

 mention Crdbro varius, a rather long and slender insect, black 

 in colour, with yellow spottings about the thorax. It prefers 

 very hard fine sand, such as is found in partially excavated 

 sandbanks, and provisions its burrows with gnats. It is 

 tolerably plentiful. 



Our last example of the earth-burrowers belonging to this 

 genus is Crabro Wesmoeli, which chooses similar localities, 

 being mostly found in sand-banks. It carries off flies of 

 different kinds for the food of its young. There is a very 

 common insect, closely allied to the last mentioned genus, whose 

 horns are worthy of notice. This is called Typoxylon figulus. 

 It is a small creature, with a large head and slender abdomen. 

 Its colour is black, and on the edges of the segments of the 

 abdomen there is a little silvery shining down. 



It generally burrows into light earth, though it sometimes 

 drives its tunnel into decayed wood. In either case, it pro- 

 visions its nest with spiders, flying into the hedges, pulling the 

 unfortunate spiders out of their webs, and carrying them into 

 the burrow. One burrow contains a series of cells, which 

 are separated from each other by partitions of sand, the 

 particles of which are firmly cemented together by some 

 glutinous substance secreted by the insect. Some species of 



