241 
wards through the skin. They then spin a cocoon either within the hole thus formed » 
or, more generally, on the surface of the tuber adjacent to it, or, as is often the case, 
on the sides of the receptacle containing this amongst the other outlets, and then 
immediately transform into the chrysalis phase. Two or three chrysalids may be 
placed side by side. They are always completely covered by particles of ‘‘ frass” or 
earth. The fully matured insect, the moth, emerges from the chrysalis shortly after 
two weeks have elapsed. The union of the sexes almost immediately takes place 
and another generation of potato-destroyers arises. The moth is quite a night-flying 
insect and only lives a few days. 
The number of caterpillars which a single potato may support is very large, and 
limited only by the amount of food which it yields. Meyrick mentions that one 
tuber must have contained quite forty larve, and we have bred fifty-eight from eight 
potatoes. ‘‘Their voracity, however, is so great and their diligence in their vocation 
so untiring, that a couple of individuals will thoroughly riddle and destroy a potato 
of fair size during their brief but mischievous career.” (Berthon.) They continue to 
feed in the tuber when even this becomes completely rotten, and in confinement 
‘deposit their eggs on potatoes when these have become not only putrid but exter- 
nally shrivelled-up lumps, whence fresh larvie are constantly being hatched.” 
( Tepper.) 
* When potatoes are attacked they soon manifest little heaps of earthy substance on 
their surface, which conceal the chrysalids of the insects or the entrances to the 
galleries, which section of the tubers discovers. This penetrating their substance 
causes potatoes affected to rot and become worthless. We do not know how soon 
the potatoes are first attacked, but if prior to the culms being dry, as is highly prob- 
able, those, too, will no doubt evidence well marked symptoms. 
KX en OF RAVAGES OF MOTH. 
According to Boisduval, as quoted by Meyrick, in certain districts of 
Algiers during a single season three-fourths of the potato crop was de- 
stroyed by this pest. Otto Tepper thus relates his Adelaide experi- 
ences: 
As far as my continued observation goes the insect causes now (i. e., in 1881), in 
its immature form of the caterpillar or grub, the destruction of hundreds of tons of 
potatoes every year by boring them, and thereby inducing putridity. During late 
years I have scarcely ever been able to get half a dozen pounds without finding a 
considerable percentage more or less affected in this way. 
Again, 
That these moths occur in other situations less confined than the entomologist’s — 
hatching case was gleaned latterly from the information a farmer gave me when speak- 
ing about thesubject. He said that he had several bags of potatoes of his own pro- 
duction, and quite healthy when dug, placed in his storeroom, where they were left 
undisturbed for a considerable time. When he at last came to open a bag for use, lo! 
quite a swarm of little moths greeted the event, and to his surprise he found the 
tubers spoiled by the grubs to a great extent. 
APPEARANCE OF THE INSECT IN AMERICA. 
The first week in November, 1891, we received from Mr. W. A. Web- 
ster, of Bakersfield, Kern County, Cal., two potatoes infested by the larvee 
of what is without doubt this insect. The larve were working just 
under the skin of the potato, forming long and narrow mines and large 
irregular blotches, giving the tubers a scabby appearance. The larve 
