The Moths and Butterflies 
379 
brown with transverse blackish bands on disk and apex. Another and per¬ 
haps the most formidable of all mill pests is the notorious Mediterranean 
flour-moth, Ephestia knehniella (Fig. 536). This insect first became seri¬ 
ously harmful in Germany in 1877, soon invading Belgium and Holland 
and by 1886 having got a foothold in England. Three years later it 
appeared in Canada and since 1892 it has been a pest in the United States. 
The moth, which expands a little less than an inch, with pale leaden-gray 
fore wings, bearing zigzag black and transverse bands and semi-transparent 
dirty-whitish hind wings, lays its eggs where the hatching larvae can feed on 
flour, meal, bran, prepared cereal foods or grain. The caterpillars spin 
silken galleries as they move about, wdiich make the flour lumpy and stringy 
and ruin it for use. In addition to this direct injury, the mill machinery 
often becomes clogged by the silk-filled flour and has to be frequently stopped 
and cleaned, involving in large mills much additional loss. When a mill 
becomes badly infested the whole building has to be thoroughly fumigated 
by carbon bisulphide, an expensive and rather dangerous process. Unin¬ 
fested mills should be tightly closed at night (if not running continuously) 
and every bushel of grain, every bag or sack brought into the mill, should 
be subjected to disinfection by heat or the fumes of bisulphide of carbon. 
An interesting as well as economically important little Pyralid is the 
bee-moth, Galleria mellonella , whose larvae live in beehives, feeding on the 
wax combs. The moths find their way into the hives at night to lay their 
eggs. This has to be done very quickly, however, as bees are alert even at 
night to defend themselves against this insidious enemy. I have intro¬ 
duced bee-moths into glass-sided observation-hives both by day and night, 
and in each case the moths were almost immediately discovered, stung to 
death and torn to pieces in a wild frenzy of anger. Many must be killed 
where one succeeds in getting its eggs deposited inside the hive. The squirm¬ 
ing grub-like white larvae protect themselves by spinning silken webs and 
feed steadily on the wax, ruining brood- and food-cells and interfering sadly 
with the normal economy of the hive. When ready to pupate they spin 
very tough bee-proof silken cocoons within which they transform to other¬ 
wise defenceless quiescent pupae. Bee-moths often become so numerous 
in a hive as to break up the successful life of the community. I have taken 
thousands of pupae, lying side by side like mummies in sarcophagi in their 
impervious stiff silken cocoons, from a single hive from which the bees had 
all fled. 
Third of the superfamilies of microlepidoptera is the Tortricina, com¬ 
prising three families, two of which number many species. The Tortricid 
moths get their name from the habit, common to the larvae of many of them, 
of rolling up the edges or the whole of leaves in which to lie protected while 
feeding, and later while in quiescent pupal stage. Not all leaf-rollers are 
