74 THE HUMBLE-BEE IV 
will completely destroy a large comb in a few days, 
riddling it with their silk-lined tunnels and reducing 
it to an impenetrable, sponge-like mass of web and 
debris. Upon this lump the humble-bees, deprived 
of all their cells and brood, sit listlessly, unable to 
help themselves. The caterpillars, when they are 
full fed, creep out of the nest in a body and spin 
their long tough cocoons, laying them side by side 
in a bunch. The cocoons form a dirty white ball 

FiG. 15.—1, Caterpillar-of Aphomia sociella; 2, Larva of Brachycoma devia ; 
2a, Puparium of ditto; 3, 3, Larvae of Volucella bombylans ; 4, Larva of 
Fannia, All natural size. 
which might easily be mistaken for a lump of rubbish. 
Here the caterpillars pass the winter, changing to 
pupee in May. The moths, which emerge in June, 
are dingy white, with brown markings and with the 
anterior wings tinged in front with green, which 
soon rubs off. 2. derhamellus, one of the surface- 
dwelling species that generally makes its nest earlier 
than the others, is very apt to fall a prey to wax- 
moth caterpillars. I have also found them in the 
nests of 2. terrestris, B. hortorum, and other under- 
ground dwellers, but I have never seen them in 
