February, '19] CAFFREY: EUROPEAN CORN BORER 93 



Serious Nature of this Imported Pest 

 Foreign History 



Foreign literature records the fact that the species is widely dis- 

 tributed in Central and Southern Europe, West Central and Northern 

 Asia, China and Japan. Corn, hemp, hops and millet are the principal 

 economic plants attacked by the pest in the old world and a loss of 50 

 per cent of the crops frequently results from its depredations. 



History in Massachusetts 



Prior to 1917 the European Corn Borer had never been reported from 

 the United States. During the period from its discovery in July, 1917, 

 to November 30, 1918, the species was found to be present in thirty- 

 four towns of Eastern Massachusetts comprising an area of about 320 

 :square miles immediately west, north and northeast of the city of Bos- 

 ton. Adjacent areas in Massachusetts, Rhode Island, Connecticut, 

 New Hampshire and Maine were examined for the presence of the in- 

 •sect, but with negative results. 



Food Plants 



The principal food plants of the species in Massachusetts were found 

 to be sweet corn, field corn, fodder corn, celery, beans, potatoes, Swiss 

 chard, beets, spinach, dahlias, gladiolus, chrysanthemums and several 

 species of the larger weeds and grasses. Although corn is the favorite 

 and preferred food plant, the great variety of other host plants has al- 

 lowed the species to become established in almost every locality 

 throughout the infested area. This greatly complicates the problem 

 of controlling the pest in the area where it is now present and of pre- 

 venting its further spread. 



Habits and Life-History 



The European Corn Borer passes the winter as full-grown, or nearly 

 full-grown, larva} within their tunnels in the host plant. They resume 

 feeding with the advent of warm weather in April or May and pupate 

 about the middle of May within their larval tunnels. The moths 

 emerge a])Out the first week of June and the females deposit their eggs, 

 generally on the lower surface of the foliage of the host plant. The 

 eggs are deposited in masses of from five to fifty eggs, individual females 

 depositing an average of 350 eggs. The habits of the resulting larvie 

 vary according to the species of plant attacked. In the instance of 

 •corn the newly hatched larvaj feed first upon the epidermis of the leaf 

 blades and then enter the stalk and tunnel through all parts of the plant 

 except the fii)rous roots. This results in a general weakening of the 



