No. 4.] THE GYPSY MOTH. 451 



by tlio destruction of the moth in Medford and other cen- 

 tral towns. Cambridge may now be considered as one of 

 the outer towns of the infested region, in which the exter- 

 mination of the moth is well under way. But considerable 

 work will be required here for several years. 



Chelsea. 



The older colonies in Chelsea appear to have been exter- 

 minated. No new colonies of any size were found during 

 L898, yet a number of caterpillars were taken here and 

 there under the burlaps. These caterpillars were evidently 

 brought in from Maiden and Everett, where they were very 

 numerous in some localities for about a month during the 

 summer. If this reinfestation can be prevented by the de- 

 st ruction of the moth in the central towns, Chelsea can be 

 readily freed from the gypsy moth in a few years. As the 

 city was thoroughly burlapped and the trees examined when 

 the burlaps were removed, and as this has been done for 

 two years in succession, it will hardly need a further ex- 

 amination, but should be burlapped again in 1899. 



Lexington. 



The good condition of Lexington, as shown in the last 

 report, has been continued and improved. There appears 

 now to be no serious gypsy moth infestation in the town. 

 The number of caterpillars taken under the burlaps in 1898 

 was insignificant, except in woodland in the south-eastern 

 corner of the town, which was formerly as badly infested as 

 any in the gypsy moth region. The moths have been greatly 

 reduced here from year to year. Some of the colonies have 

 been entirely exterminated and others are now on the verge 

 of extermination. For instance, in one colony in which 

 1,962 larvae were taken under burlap in 1897, only 353 were 

 taken in 1898. In another, where 57,444 caterpillars were 

 taken in 1897, only 8,386 caterpillars were taken in 1898. 

 The present policy of thinning out the trees in these wood- 

 land colonies will greatly assist in extermination, as well as 

 reduce the amount of work necessary to secure it. A thor- 

 ough search of the entire town is now in progress. In this 



