348 LIFE STORIES OF AUSTRALIAN INSECTS. 



describes it: ''It entered this cell as a tiny slender 

 worm through a miniite orifice or crack, but it is 

 now much increased in size, and exit for a creature 

 of its organisation is not possible. For some montlis 

 it remains a quiescent larva in the cell of the bee, 

 but in spring of the succeeding year it undergoes 

 another metamorphosis and appears as a pupa pro- 

 vided with a formidable apparatus for breaking 

 down the masonry by whicli it is imprisoned. The 

 head is large, and is covered in front with six hard 

 spines, to be used in striking and piercing the 

 masonry." When the hole is made in the mud cell 

 the adult escapes from the puparium. Tlie larva or 

 maggot feeds on the larva of the mason bee by suck- 

 ing the juices of the bee-magot. 



Certain bombylid flies parasitise the egg masses 

 of locusts 



We bred out a small bombylid fly (Plate 42, Fig. 

 4) from the mud cells of an eumenid wasp. The 

 pupal shell was found outside the mud cell and 

 we give a sketch of same (Plate 42, Figs. 6 and 7), 

 for it has these six hard spines for escaping from the 

 mud cell. The adult fly was a beautiful little insect 

 with smoky wings. 



