80 WORCESTER COUNTY HORTICULTURAL SOCIETY. [1896. 



undoubtedly destroy some beneficial insects, but the proportion of 

 beneficial insects to injurious ones is exceedingly small. 



In speaking of the gypsy moth (Porthetria dispar), Mr. Forbush 

 said that it was undoubtedly the most serious pest which had ever 

 been introduced into Massachusetts from a foreign country. Its 

 introduction into Medford, Mass., by an experimenting Frenchman is 

 well known. Although his attempts at breeding a hardy silkworm 

 were a failure, he has given us the gypsy moth, which is certainly one 

 of the hardiest insects in the country. The caterpillars of this insect 

 have been placed experimentally in a temperature of forty degrees 

 below zero and have survived the test. They also survive the great- 

 est summer heat. 



This insect is an illustration of the increased injuriousncss of intro- 

 duced species. Though unlike many other introduced species it was 

 considered a pest in its native country, it has given evidence of 

 greatly increased destructiveness in this country, 



European authors inform us that this insect has been a great 

 scourge in many parts of Europe during the last century and a half ; 

 that the sickening and death of many trees has been attributed to it ; 

 that its ravages are still very extensive in certain parts of Europe, 

 especially in Russia, where in recent years it has been very destructive 

 in many provinces. In 1879-80 these caterpillars multiplied in 

 frightful numbers and spread over an immense territory in Russia 

 equal to nearly all our Atlantic States. They attack not only forest 

 trees but fruit trees and nearly all kinds of vegetation. They have 

 been particularly destructive in the forests of Russia during the past 

 two years, having devastated large tracts. Their introduction into 

 Massachusetts was forgotten or unnoticed for some years. After 

 they had become acclimated they increased with great rapidity, 

 destroying the foliage of nearly all kinds of trees, plants and shrubs, 

 eventually killing many trees, destroying garden crops, spreading 

 over a great portion of the town and scattering in the meanwhile into 

 other towns in the vicinity. They not only destroyed vegetation but 

 invaded the houses, covering them so that in some cases it is said the 

 color of the paint on the houses could not be distinguished. In spite 

 of all that was done by the citizens and finally by the town authori- 

 ties to hold them in check, they increased so that the Legislature was 

 called on to aid in the attempt at their extermination. The work, 

 which was at first placed in the hands of a special commission, was 

 afterwards delegated to the State Board of Agriculture, which has 

 carried it on for four years. This work has been successful in so 



