78 
TUBNIP. 
■ 
Later on, on October 16th, more specimens were sent, which 
showed the Moth to be Plusia Gamma , or Silver-Y Moth, sometimes 
Plusia Gamma. 
Silver-Y Moth, caterpillar, and chrysalis in cocoon. 
known as Beet Moth, which is figured above, together with its “ half- 
looper ” caterpillar and the light web cocoon in which it changes to 
chrysalis. 
This Moth does not appear to trouble us much here, but on the 
Continent it occurs from time to time in vast numbers, and the cater¬ 
pillars are most general feeders. 
Amongst cultivated plants which they attack are leguminous 
plants, such as Peas, Broad Beans and Kidney Beans, and likewise 
Clover. Turnip leaves and various plants of the Cabbage kind, and 
likewise Lettuce, and Beet also, are sometimes severely injured. Corn 
crops have escaped a while when bad attack was going on, but after a 
time the Oats were found to be suffering. 
Amongst the common weed plants which serve as food, John Curtis 
mentions Thistles, Burdock, Nettles, and others, and also grasses. 
From continental observations it appears that some of the cater¬ 
pillars hybernate; these are only about half-grown when winter comes, 
and reappear to go on feeding and complete their growth in the 
following year ; but I have not found any note of this taking place 
with us, and I have had specimens as chrysalids in cocoons developing 
into Moths in the middle of October. This is an important point to 
know more about, as, in case of P. Gamma only passing the winter 
with us, either as stray specimens of the Moths or as chrysalids above 
ground, exposed to changes of weather, it would at once account for 
the attacks being much less severe than where there is a late brood of 
caterpillars safely stored during winter in their own chosen shelters 
to come out again in spring. 
Where the attack is found on Turnips any measures calculated to 
brush them from the leaves, such as those advised (p. 75) for Sawfly 
caterpillars, would be desirable. In gardens hand-picking is best, so 
as to make a thorough clearance at once. 
