120 



Marvels of Insect Life, 



A somewhat similar story is told of an American beetle named Epicauta,^ whose 

 food in the grub stage consists of the buried eggs of the Rocky Mountain locust ; "^ 

 and the life-history of our wasp-nest beetle,^ as elucidated by Dr. T. A. Chapman, 

 is in general much like it, making allowance for the different character of its food. 

 Our wasps do not fill their cells with honey as do the bees, but feed their grubs upon 

 partly digested Insect food from the mouths of the workers. The wasp-nest beetle 

 was long known to pass its larval stages in the wasp cells and to be parasitic upon 

 the wasp-grubs, but nothing definite was known as to its transformations until 

 1870, when Dr. Chapman published the results of his patient observations. It is 

 a slender beetle about half an inch long, of a bluish-black colour, and with the wing- 

 covers running off to 

 a point behind, leaving 

 a wide gap between 

 them, much as in the 

 case of the oil-beetle. 

 But the oil-beetle's 

 wing-covers cover no 

 wings, and are them- 

 selves soldered to- 

 gether at the base so 

 that thev are not 

 moveable. The female 

 wasp-nest beetle is 

 believed to deposit her 

 eggs in spring or sum- 

 mer near the entrance- 

 holes to the under- 

 ground nests of the 

 y \ common wasp and the 



/ J equallv common Ger- 



( man wasp.^ They 



hatch into little crea- 

 tures a fiftieth of an 

 inch long, and much 

 like the triungulin ol 

 the oil-beetle, black in colour. The two or three claws of the feet are supported by 

 a large transparent sucker, and there is a similar sucker on the last segment of the 

 hind-body. " The little animal frequently stood up on this, and pawed the air with 

 its feet, as if hi search of some fresh object to lav hold of." Each segment of the 

 hind-body bears on each side a short spine, which }>oints backwards. 



This little creature is supposed to make its way afoot down the passage into the 

 nest chamber of the wasp, and to climb up into the combs and enter a cell in which 

 there is a nearly full-grown wasp-grub. Attaching itself to this grub the intruder 

 bores into its back a little behind the head, and enters the body, remaining a little 

 below the skin. It feeds for a time upon the internal parts of the wasp-grub, and 



' Epicaulq vittata. '■^ Caloptcnus spretus. ''Metnccns paradoxus. '' Vespa vulgaris and V. germanira 



Photos bv\ 



SlTARIS-J:>EETLE. 



[E. Step. F.L.S. 



This beetle has a life-history in its main lines similar to that of the oil-beetle, its victim being a 

 solitary bee. The story is told in a succeeding plate. The two sexes are shown hin-, four times 

 larger than life-size. 



