_ Se Wes = 
species, those most affected being mentioned first in the lst and those 
least affected last: Soft or silver-leafed maple (Acer dasycarpum), 
box elder (Acer negundo), linden (Tila), Virginia creeper (Ampe- 
lopsis quinguefolia), bittersweet (Celastrus scandens), sumae (Rhus), 
grape (Vitis), and willow (Salix). The summer food plants 
observed have been Spirwa Van Houtteii, S. arguta, and 8. pruni- 
folia; Philadelphus grandifiorus and P. coronarius; Cornus mascula, 
C. siberica, C. stolonifera, and C. paniculata; Ribes aureum and R. 
sanguineum,; Hydrangea: Rudbeckia; Symphoricarpus racemosus 
and S. vulgaris; Syringa, several varieties; Viburnum, several varie- 
ties. Ihave not found it upon either the sugar maple (Acer sacchari- 
num) or the Norway maple (4. platanoides), even where these trees 
were surrounded by the soft maples, except in such small numbers as 
to be very inconspicuous. 
The work of spraying began the middle of July and continued 
until September 1. The work was done under my constant super- 
vision by some senior students of the Michigan Agricultural College. 
Two outfits on wheels with hand pumps were used, these being the 
most convenient in getting around from tree to tree. Both the 
vermorel and bordeaux nozzles were used. The trees sprayed were 
mostly quite large, requiring a 60-foot hose to reach the top. The 
operators wore fireman’s oiled suits and began the spraying at the 
top by climbing the tree, finishing at the bottom limbs. ‘The work 
was thoroughly done, so far as possible every leaf being covered. 
When I first took hold cf this work I had expected to Inll the in- 
sects readily “ with a weak kerosene emulsion.” All the entomolo- 
gists said this was the remedy, and my own fourteen years’ experience 
in practical spraying work told me the same thing. I began with an 
S per cent kerosene emulsion, which was increased within a few days 
to 10 per cent, then to 124, and finally to 15 per cent. Practically 
none of the insects were killed with either the 8 or 10 per cent emul- 
sions. An examination at Professor Forbes’s office of leaves sprayed }j 
with 124 per cent, some days after, showed that something over 50 _ 
per cent were killed, but the death of some of these was doubtless 
from natural causes. The 15 per cent emulsion killed the greater 
portion cf the Pulvinaria, but as this strength took practically all 
the leaves off the box elders, all from the lindens, and fully one-half 
from the maples, the remedy was at least equal to the disease. A 10 
per cent emulsion is all that can with safety be applied to the linden 
cr box elder, while a 124 per cent is all that can safely be applied to 
the maple. 
In this. connection some experience in the making of the emulsion 
may be of interest. With 2,500 large trees to spray, scattered over a 
large territory, the matter of making the emulsion was of consider- 
able importance. But, as “necessity is the mother of invention,” it 
