1908. J PUBLIC DOCUMENT- -No. 73. 205 



moths, and also of seeing the results of the work which has been done 

 to destroy these pests on the shade trees and other trees along high 

 roads and streets and in ornamental grounds over an extensive area in 

 the State of Massachusetts around the city of Boston. 



Leaving your office at 9 o'clock on the morning of June 24, in an 

 automobile, we passed through Cambridge, Somerville, Maiden, Melrose 

 and Wakefield to Saugus. I was much pleased and surprised to note 

 the excellent condition of the trees which had been kept free of injury 

 by caterpillars by means of the measures which your commission has 

 adopted, viz., the spraying of the trees with the arsenate of lead mix- 

 ture, the burlapping and banding of trees with tanglefoot, and by a 

 discreet cutting out and burning of useless trees and undergrowth. The 

 destruction of the eggs of the gypsy moth by creosoting and the effect- 

 iveness of this method were plainly visible by the masses of dead eggs 

 on many trees. 



At the parasite laboratory at Saugus we were received by Mr. F. H. 

 Mosher, the entomologist in charge, and shown through the various 

 rooms, where the large consignment of parasitized material from Dr. 

 L. 0. Howard and his agents in Europe was being unpacked and cared 

 fo'r. I knew of this work in a general way, but had no idea, before I 

 visited the laboratory, of its great scope or of the skill and care with 

 which the details are being carried out at Saugus by a body of enthusi- 

 astic scientific assistants, all of whom, although suffering more or less 

 from the painful " brown-tail rash," continued their investigations with 

 unabated interest. The painful irritation caused by the barbed hairs 

 of the brown-tail moth caterpillars complicates this problem consider- 

 ably, making it necessary to adopt special means to prevent to as large 

 a degree as possible the poisoning of the hands and faces of those 

 engaged in opening, examining and sorting the boxes of parasitized 

 material which are constantly coming to hand, and which must be 

 promptly attended to. 



At the time of my visit the work with the Pteromalus, which was 

 called provisionally processionece when received, and upon which Dr. 

 Howard based much hope, was practically finished for this season. I 

 was able to see the cases in which these parasites were reared, and the 

 great amount of care which was necessary in examining the insects so 

 as to destroy secondary parasites when liberating the beneficial species. 

 It is satisfactory to know that large numbers of this important enemy 

 of the brown-tail moth in Europe have been successfully reared and 

 liberated in several localities. It is hoped with reason that by this 

 insect both the brown-tail and gypsy moths will be much reduced in 

 numbers. 



On visiting the breeding cages out of doors we found that Tachina 

 flies of nearly a dozen species were emerging in large numbers and in 

 a healthy condition. These also, as soon as all species which were not 

 actually known to be primary parasites of the moths had been de- 



