282 THE CANADIAN ENTOMOLOGIST. 



Prof. J. B. Smith inquired whether or not the infested territory had 

 been reduced. 



Mr. Forbush replied that the chief reduction had been made on the 

 outside, but that many colonies had also been exterminated in the centre 

 of the region. The greatest progress was made during the first and 

 second years of the State Board work. There had been cases of re- 

 infestation of " exterminated " territory from larvae brought from the 

 infested centre. 



At the request of Prof Fernald, Mr. Kirkland spoke briefly of the 

 experimental work of the past year. He stated that two main hues of 

 investigation had been followed : experiments with insecticides and the 

 study of natural enemies. In conjunction with the chemist who prepared 

 the compounds, a large series of arsenical preparations had been tested. 

 Experiments wiih Paris green and correctives to prevent burning gave 

 negative results. Sulph-arsenates did nbt give results superior to arsenites. 

 Experiments with arsenite of lead versus arsenate of lead had shown the 

 two poisons to be about equal in insecticidal properties. The former is 

 somewhat heavier than the latter, and does not stay in suspension as well. 

 The experiments with barium arsenate had already been described. 



Of the few hymenopterous parasites taken, Pimpla pedalis and 

 P. tenuicornis had been reared in small numbers from Porthetria dispar. 

 The first brood of these insects attacks the CUsiocampa americana, and 

 the second brood emerges in time to prey somewhat on P. dispar. The 

 work on life-histories of the predaceous beetles had been carried out by a 

 man especially detailed for the purpose, Mr. A. F. Burgess, and much 

 valuable information obtained. 



Many predaceous Heteroptera of the genera Euschistus and Podisus 

 had been reared and studied by Mr. Kirkland, and many doubtful points 

 in their life-history cleared up. These insects when emerging from their 

 hibernating quarters attack the larvre of the tent caterpillar, CUsiocampa 

 americana, in great numbers. 



The Japanese parasite of the gypsy moth had been received from 

 Rev. H. A. Loomis, Yokohama, but the cocoons of the parasite were 

 infested by a secondary parasite. Only a few of the primary parasites 

 were alive when received, and these died without attacking gypsy moth 

 larv» {" enfeebled ")• This Japanese parasite would be worthy of careful 

 study should the work of exterminating the gypsy moth cease. The 



