102 THE GYPSY MOTH. 



the centre of the town, and the main line of the southern 

 division of the Boston & Maine Railroad, passing through 

 Somerville and West Medford. The old turnpike roads from 

 Boston to Salem, Newburyport, Lawrence and Lowell all 

 pass through the infested region. The roads which pass 

 through this reo;ion from Boston lead outward toward the 

 north, north-east and west. 



The continual and immense traffic between Boston and 

 towns to the northward, coming and going through the badly 

 infested region, together with that in and out of the region 

 itself, has resulted in spreading the moth to many of these 

 outer towns. This has been brought about chiefly by means 

 of the transportation of caterpillars on vehicles. In the 

 spring of 1889, and in other years when the moths were in 

 greatest abundance in INlalden and Medford, the young 

 caterpillars, when disturbed by wind or by any object strik- 

 ing the branches, hung in great numbers by their silken 

 threads from the trees in a manner similar to that habitual 

 with the common canker worms. While suspended in this 

 way above the street they were often struck by passing 

 vehicles upon which they dropped, remaining either until a 

 stopping place was reached or until shaken ofi" along the 

 roadside.* Regular teaming, daily or at stated intervals to 

 or from a badly infested spot during the time when the 

 caterpillars were very numerous on wayside trees, would 

 finally result in transporting numbers of them to certain 

 localities where the wagons stopped. A market gardener's 

 wagon going regularly through the infested region to Boston 

 and return, and passing under infested trees along the way, 

 would be very likely to carry caterpillars into the yard at the 

 end of the route. If a single pair of the caterpillars thus 

 transported survived and passed through their transforma- 

 tions, and the resulting pair of moths mated, the seed for a 

 colony might be planted. Even if one female caterpillar 

 survived and transformed into a moth, and there were a simi- 

 larly surviving male moth in the neighborhood, under favor- 

 able conditions the latter might be attracted to the former 



* All forms of the moth have been found on wagons standing under trees. The 

 caterpillars frequently crawl for shelter under the bodies of standing vehicles. 



