GIPSY MOTH WORK IN NEW ENGLAND. 19 
causing spread into Connecticut or the area in Massachusetts south 
of Worcester. Recently, however, the infestation has increased to 
a great extent in southeastern Massachusetts and Rhode Island, 
and unless vigorous means are taken to abolish these sources of sup- 
ply, rapid infestation of eastern Connecticut and territory in Massa- 
chusetts lying immediately north of that State will result. In fact, 
during the past season a large increase has been found in the western 
tier of towns in Rhode Island and the eastern tier in Connecticut. 
In eastern Connecticut the white oak, which is one of the most favored 
food plants of the gipsy moth, is exceedingly common in the wood- 
lands, and the difficulty of controlling the moth under these condi- 
tions is very great. 
A series of experiments has been conducted to determine how far 
male moths will be attracted by the females. The purpose is to deter- 
mine the probability of scattered females being fertilized if they occur 
at a long distance from a gipsy-moth colony. 
SECONDARY INSECT INVESTIGATIONS. 
In the fall of 1912 large numbers of oak trees in the areas that had 
been defoliated by the gipsy moth were found in a dying condition. 
Examination showed that many of the trees had been attacked by a 
bark borer, which proved to be Agrilus hilineatus Web. The matter 
was taken up with Dr. A. D. Hopkins, in charge of Forest Insect 
Investigations of the Bureau of Entomology, and arrangements were 
made for cooperative study of this insect. Dr. Hopkins was to direct 
the work, and the salary and expenses of an assistant, Mr. H. A. Pres- 
ton, who was to give his entire time to the work, were to be paid by 
tins branch. Investigations have been carried on and the life history 
of the insect worked out. It appears from the information secured 
that continuous work on this project is not necessary, and the coopera- 
tive arrangement was discontinued July 1, 1914. The data relative 
to the life history and habits, as well as control measures, is in the 
hands of Dr. Hopkins and will doubtless be published at an early date. 
For the information of woodland owners who wish to preserve their 
oak trees it can be stated that all trees which are in a dying condition in 
September should be marked so that they can be cut during the winter. 
The wood should be removed from the lot and if it can be used for 
fuel the hibernating larvse will be destroyed. Inasmuch as the oak 
is very favored as a food plant by the caterpillars of the gipsy moth and 
as the Agrilus beetles prefer to attack weakened trees, it would seem 
rather difficult to preserve oak growth unless considerable expense was 
involved in spraying or treating gipsy-moth egg clusters in order to 
keep the trees in a vigorous condition. This is impracticable in most 
woodlands in the infested area. Park or ornamental trees can be 
handled in this way and the cost is not prohibitive. 
