72 CALOSOMA SYCOPHANTA. 



Other colonies were released. A stock of beetles was added to one of 

 the Ijynnfield colonies that had been liberated the previous year, and 

 new colonies were put out at North Woburn and Peabody. The first 

 lot of beetles placed in the North Woburn colony was on July 31, 

 which was late in the season for effective work, and on August 2 more 

 beetles were added to the colony, makino; a total of 50 males and 50 

 females for this liberation. The colony in Peabody consisted of 25 

 males and 25 females, which were released August 28, 1907. 



In 1908 less than 700 live beetles were received from Europe ; hence 

 only a small number of adult colonies could be liberated. Experi- 

 ments were carried on, however, in rearing the larvas of this species 

 at the laboratory, and as a result of this work it was possible to liberate 

 2,300 larva? in field colonies during the breeding season. The gen- 

 eral plan of liberation was to place all the colonies in badly infested 

 sections, where plenty of food was available, and where the insects 

 would be disturbed as little as possible by hand methods of suppressing 

 the gipsy moth. Several colonies were liberated on estates, and in 

 some cases active hand suppression methods were carried on in order to 

 prevent defoliation by the gipsy moth caterpillars. In a few instances 

 the trees were heavil}^ sprayed, and, although this was not in accord 

 with the intention when the plantings were made, it gave an oppor- 

 tunity for securing data on the ability of the insects to survive in case 

 they were handicapped by spraying or other control measures. A 

 few small colonies were also liberated in York County, Me. 



In 1909 the work was continued along the same lines, but a larger 

 number of larvae was planted in field colonies. It might be added 

 that a single colony was liberated in the fall of 1909 at Sandwich, 

 N. H., the reason for this being that while no gipsy moths had been 

 found in this town, the maple, beech, and other forest trees were suffer- 

 ing from a severe outbreak of Heterocampa guttivitta Walk., and it 

 was thought advisable to release a colony for the purpose of deter- 

 mining whether the insects would be able to survive at that northern 

 latitude and do any considerable amount of good in reducing the num- 

 ber of these caterpillars. 



In 1910 this work was carried on in much the same way, but an 

 effort was made to liberate colonies in towns where none had been pre- 

 viously placed, providing, of course, that suitable localities which were 

 badly infested could be secured for the purpose. The result of this 

 policy has been that practically all the towns in Essex, Middlesex, and 

 Suffolk Counties, and a few in Norfolk, and a single one in Plymouth 

 County, Mass., have been supplied with one or more colonies of the 

 Calosoma beetle. 



In the first larval colonies from 75 to 150 or 200 specimens were re- 

 leased, but since that year it has been the practice to put out not less 

 than 200 specimens in a colony, unless some of the adult beetles are 



