10 
Further protection against borers may be given by a thick coat 
of paint applied to cut surfaces and repeated after the first coat is 
dry. Any paint will do which is made of linseed oil and lead. 
Ordinary ready-made paints are nearly useless for this purpose, 
since they are likely to crack and scale off. As a general preventive 
of borer infestation, the trunk of the tree and the larger branches 
may be painted with a mixture intended to prevent the laying of 
the eggs. Some of the mixtures recommended are prepared as fol¬ 
lows : To a gallon of soft soap add half a gallon of hot water and 
a pint of crude carbolic acid, or a half pint of the refined acid, 
stirring the latter thoroly in and leaving the mixture over night. 
Then dilute with eight gallons of water and apply with a white¬ 
wash brush. Or, to a saturated solution of washing soda add soft 
soap to make a thick paint, and stir in a pint of crude carbolic acid 
and half a pound of Paris green to each ten gallons of the wash. 
Or, in six gallons of a saturated solution of washing soda dissolve 
a gallon of soft soap, add a pint of carbolic acid, mixing well, slake 
enough lime in four gallons of water to form a thick whitewash 
as it is added to the foregoing, and finally stir in thoroly a half 
pound of Paris green. One or the other of these substances should 
be applied, as frequently as may be necessary to keep the bark 
moist, from the middle of May to the end of July. 
The Insects chiefly Concerned 
Of all the many insect enemies to the elm in Illinois, much the 
most destructive is the “round-headed” borer commonly known to 
entomologists as the elm-borer (Saperda tridentata ). Even more 
abundant than this, but less injurious, is a much smaller burrow¬ 
ing grub, the larva of the reddish elm snout-beetle (Magdalis anni- 
collis). It is the common elm-borer, working in the bark and the 
sap-wood of the elm, to which the present condition of our dead 
or dying trees is most commonly attributed by those searching for 
a cause. It is a common belief, however—difficult to prove, it is 
true, and at best a matter of intelligent opinion—that this beetle 
attacks by preference trees already suffering from some disease or 
other crippling condition. It would be easier to make sure that 
this is true if it were not for the fact that it is difficult to detect 
the beginnings of injury by this insect. Often the first notice one 
has of its presence is a general failure of the tree, due to an in¬ 
festation already extensive and long continued; and whether this 
failure began before the borer injury or was caused by it, one can 
not positively tell. This is, indeed, a matter of little practical im¬ 
portance, since one must proceed in the same way whichever view 
he takes. That the elm snout-beetle infests dying trees in prefer- 
