THE NATIONAL NURSERYMAN 
47 
winter in silken pockets of firmly webbed nests attached to 
the smaller twigs. These nests usually have one or more 
partly rolled leaves included in the structure and are an 
inch to two inches or more in length and therefore easily 
detected. These nests, near the tips of twigs, are very dif¬ 
ferent from the large, relatively open nests made in forks of 
branches by our common tent caterpillar, and are much 
smaller than the open webs enclosing many brown leaves, 
made by the fall web worm in late summer and early fall. 
The brown-tail moth caterpillars emerge from their snug 
retreats in the spring and commence feeding on the tips of 
the branches. The full grown, reddish-haired caterpillars 
are an inch or more in length and have a series of long, white 
spots on either side. The snow 
white, brown-tailed moths, 
with a wing spread of about 
\ l /2 inches, fly in early July 
and deposit on the leaves 
long masses of eggs thickly 
covered with brown scales. 
The eggs hatch about the first 
of August and the young cater¬ 
pillars at this time skeletonize 
the leaves and commence the 
web which is later to form the 
winter shelter. 
It is comparatively easy 
to destroy the young cater¬ 
pillars by spraying in late sum¬ 
mer with an arsenical poison 
or making a similar applica¬ 
tion in the spring at the time 
the insects begin their opera¬ 
tions. Another very practical 
method is to cut off and burn 
the wdnter pests. Our chief 
aim at present is to prevent 
the wide-spread establishment 
of this insect with the import¬ 
ed French stocks noted above. 
This can be accomplished in 
the following manner: 
Recommendations. 
All imported nursery stock should be unpacked and care¬ 
fully examined at destination by a thoroughly competent 
inspector who should insist upon the most careful observance 
of certain precautions. 
1. All brown-tail moth nests should be carefully removed 
from the seedlings without breaking, or else the infested 
plant laid to one side and the plant and all promptly burned. 
2. All packing materials, including boxes in which 
infested seedlings are received, should be burned at once. 
This also includes any material with which packing from 
infested boxes may have been placed. 
3. Stock not actually infested but in boxes with in¬ 
fested stock, must be thoroughly fumigated with hydio- 
cyanic acid gas or dipped in a standard miscible oil diluted 
with about 20 parts of water. 
Recent experiments conducted by us have shown it to 
be unsafe to depend upon the ordinary fumigation with 
hydrocyanic acid gas, even when continued for one hour. 
A thorough fumigation with 98% cyanide of potassium, 
using 1 oz. to 100 cubic feet of space and continuing it 
three hours or more, is the minimum that can be advised. 
It would be better to prolong the fumigation to four or five 
hours, or to use the amount of cyanide and fumigate at 
least six hours. Even this treatment is insufficient to 
destroy the caterpillars within the nests and can be relied 
upon only to kill the crawling caterpillars which might be 
overlooked on nursery stock. The tenacity of life ex¬ 
hibited by these hibernating caterpillars is remarkable and 
cannot be too strongly em¬ 
phasized. The nests are more 
or less open and there is 
danger of the caterpillars 
crawling out, if the nests are 
left for a day cr two exposed 
to ordinary room temper¬ 
atures. Consequently, too 
great care cannot be exer¬ 
cised in treating stock so that 
nothing of the kind can sur¬ 
vive. The packing materials 
have so little value compared 
with the importance of pre¬ 
venting this pest becoming 
established at points ’•emote 
from those known to be infest¬ 
ed, that we have no hesitancy 
in advocating their immediate 
destruction by fire. 
It is perhaps unnecessary 
to add that it is by all means 
advisable for parties receiv¬ 
ing such stock to keep a close 
watch for the possible appear¬ 
ance of a few caterpillars in 
the spring. It would be 
much easier to destroy stray 
individuals then than to con¬ 
THE BROWN-TAIL MOTH SITUATION IN NEW YORK. 
BY GEO. G. ATWOOD, CHIEF, BUREAU OF INSPECTION. 
This insect is unknown in this country except in portions 
of the New England States where it has spread in less than 
twenty years from near Boston, Massachusetts. 
It is supposed to have been introduced from Europe on 
importations of nursery stock previous to, or about 1890 
and as the insect is quite common to nearly the whole of 
Europe and as the first center of infestation was traced to 
the grounds of an importer it is reasonable to believe that 
nursery stock importation was the medium of introduction. 
From eastern Massachusetts the spread of the insect 
towards the west and south has been comparatively slow 
but the spread to the north and east has been in the direc- 
Nests of Brown-tail Moths. 
trol a bad infestation later. 
