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 groat. 



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 bilineatus 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 

 this 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 ft 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 larvas 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. 



