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, which 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 



