TREE INSECTS. 55 
As these insects do their damage while completely concealed 
beneath the bark, very few natural enemies have been noted. 
We did, however. find two,—one an egg parasite belonging to the 
family Trichogrammidae and the other a larval parasite belonging 
to the genus Atanycolus, both Hymenopterous parasites. These 
were determined by Messrs. Rohwer and Crawford. No further 
record was taken, although we expect to obtain more upon further 
research. Working as they do beneath the bark, no artificial 
remedy has yet been found to kill these pests while they work. 
As the life history shows, our only point of attack is while the 
beetles are laying eggs, a period of only one month. Although we 
have in mind a number of experiments, the only results obtained 
thus far have been with preventive remedies; that is, material 
put on the tree to deter the adult beetle from laying eggs. Experi- 
ments so far show that iron-sulphide or Bordeaux mixture sprayed 
on the trunks of trees discourage the visiting of such trees by 
the insects. 
It has been found in our work that a relationship exists be- 
tween these insects and a disease, the shoe-string fungus. Many 
times the borers have been found present with the disease. In 
some cases, the fungus alone was present and in others the insects 
alone. Whether the fungus is necessarily present, first acting as 
a primary cause of death to the tree or whether the combination 
causes death, is a question for further investigation. 
Two insects very commonly asked about are the fall canker 
worm and the cottony maple scale. So much has been written 
about these that it is perhaps undesirable to take much space in 
this report. The fact remains that these insects can be success- 
fully combated, but it requires absolute co-operation among all 
concerned in a community and long tedious effort. For literature 
on these insects, write to the Division of Entomology, University 
Farm. 
Another insect doing considerable damage and new to the 
state is an oak twig-girdler. The work is entirely different from 
that of the oak twig--pruner and the difference is easily recognized. 
The tree seems to be infested with blight, many of the leaves on 
the ends of the small twigs withering. The damage is done by a 
small grub, a close relative of the two-lined chestnut borer. The 
adult has not yet been taken. As the life history is not known at 
the present time, only one method of combating the insect has 
been tried and no results have been obtained to date. This 
