IV PAKASITES AND ENEMIES 77 
one fora humble-bee. It is a singular fact that if 
one kills a female Volucella she at once commences 
to lay eggs, and so great is the vitality of the ovi- 
positing apparatus that on one occasion I found 
about a dozen eggs had been laid by a female in my 
cyanide killing-bottle. No doubt if they are stung 
to death by the humble-bees in their nests they are 
always able to finish laying their eggs. The eggs 
are large and hard, and when new laid, like those 
of many insects, are thinly coated with a glutinous 
substance, which quickly hardens and fastens them 
to one another and to the object upon which they 
are laid. The larve are of a dirty yellowish-white 
colour and slightly flattened, and have a tough 
wrinkled skin; they have six long spines arranged 
in a semicircle under the anus, and also two rows of 
rudimentary spines running the whole length of the 
body on either side. They attain the large size of 
3 in. to Zin. in length and }in. in width. They 
live in the debris under the comb and are said to be 
scavengers ; they certainly have done no harm to 
the brood in my nests. 
The larve of another kind of fly, Faznza, are 
often found on the earth in the nest cavity. They 
are considerably smaller than the Volucella larve ; 
their colour is dirty brown, and they have two 
rows of spines running the whole length of the 
body on either side and two more rows closer 
together along the top; at the anal end the 
spines are longer. These are also scavengers and 
feed upon excrement. The perfect fly is dull 
