y - 48 · Bulletin N0. 133. A
A THE FIJAT-HEADED APPLE TREE BORER.
° (Ohrysobothris femomta).
On the southwest sides of the trunks of apple trees the bark is
i I sometimes found killed in a region just above the ground, and min-
ing the bark of this region are one or more small white grubs with W
a peculiar rounded and somewhat flat head region, for the flat
part is not the head, but the body division just behind it. _The
body is kept bent like the letter U, a feature by which this borer
may be recognized from any other likely to be found working on .
_ apple trees. i Q
l The insect placing the egg is a gray beetle with metallic reflec—
~ tions, and somewhat flattened body. It will measure 0.44 to 0.48 x
. inch in length. Adults emerge early in the spring and place their
4 eggs under the loose bark and in crevices anywhere from the ground
` up to the branches, and sometimes out on the bases of the latter.
It appears to prefer the southwest sides of trees, but it is very prob- _—
able that its prevalence here is due to the fact that the bark has
been rendered defective by what is sometimes called sun—scald; the ‘
beetles prefer breaks of this sort as places to put their eggs. I
suppose there can be no question that the insect prefers feeble trees, L;
i but it seems equally certain that it helps in the destruction of trees it
once attacked, since it is known to completely girdle the trunk in A
I _ some cases.
A common practice among apple growers is to go over the trees Q
in the fall each year and cut out any borers that may have attacked ‘
_ them. Preparations of soap and other materials have been used
to deter the beetles from laying their eggs on the trunks. They Y
¤ serve for a time, but must be renewed occasionally during the egg-
laying season to be effective. A mixture of washing soda and soft .»
soap has been highly recommended for the purpose. ‘ .· `
Sticky preparations such as Dendrolene are calculated to keep l
A the adults away and have been tested to some extent for the purpose.
A preparation called Tree Tanglefoot, somewhat like the material
on sticky fly-paper has been tried by different entomologists and' "
found harmless to the tree trunks, and very durable after exposure. by
From my experience with such preparations for the Elm Leaf-
beetle I am disposed to consider them valuable for insects attacking, ;
I or creeping upon, the trunks. The substance is manufactured by