Insects of Shade Trees and Their Control. 59 
kerosene emulsion (p. 12-13) or miscible-oil solution (p. 12-13) is 
recommended for killing the very young larve in the outer bark. On 
valuable trees some measure of relief may also be obtained by paint- 
ing the eggs with creosote or carbolineum or by digging out and kill- 
ing the young borers in early fall as they begin to tunnel their way 
into the wood. Heavily infested and badly damaged trees should be 
removed and 
burned or ex- 
posed to drying 
during thef 
winter. 
For a full ac- § 
count of the as- 
pen borer see 
Farmers’ Bulle- 
tin 1154 which 
will be sent on 
request. 
i 
ae 
= 
= 
COTS. 
= NN 
ON 
Ne 
th 
$63 
# 
BRONZE BIRCH 
BORER.” 
Character and 
extent of in- 
jury. — During 
the past 20 years 
or so the birch 
trees of many 
city and private 
parks have died. 
As the -top 
branches die 
first, the vitality Fic. 38.—Work of bronze birch borer on trunk of white birch; 
of the trees bark removed to show larval galleries. Somewhat reduced. 
(Chittenden. ) 
gradually de- 
teriorates and finally, one or two years later, the entire tree succumbs. 
This condition is usually due to the work of the bronze birch borer. 
Evidence of infestation —The following are signs that the trees are 
infested : (1) Characteristic reddish or rusty brown spots or discolora- 
tion on the white bark of the trunk and larger branches, which, on 
being cut through, usually disclose peculiar winding burrows (fig. 38) 
in the bark of the wood; (2) ridges (fig. 39) in the bark on the branches 
which often develop over the burrows of the insect; (3) dying tops. 
8 Agrilus angvius Gory. 
