40 BULLETIN 1103, U. S. DEPARTMENT OF AGRICULTURE. 



of Jones County, the south shore of Pamlico County, and the north- 

 ern part of Carteret County. 



This was followed about the middle of April by reports coming- 

 in from Norfolk and the eastern-shore districts of Virginia. In 

 this State both the entomologist and the plant pathologist were in- 

 clined to believe that the seed-corn maggot was of secondary import- 

 nnce and that the chief damage was being occasioned by a Fusarium 

 disease. 



By April 21 serious reports were coming in from the eastern shore- 

 of Maryland and the southern half of New Jersey, where by actual 

 count 10 per cent of the seed pieces were damaged to such an extent 

 that the plants failed to develop properly. By May 1 this outbreak 

 had become so serious that 20 per cent of the hills were missing in 

 the infested fields. In this State it also did serious damage to pea 

 and bean seeds and lettuce plants. 



Early in May potato seed pieces were being attacked on Long- 

 Island, but here the outbreak was not at all serious. 



About May 10, reports -were received from Massachusetts that 

 this insect was seriously attacking the onion plantings in the Con- - 

 necticut River Valley, some fields suffering 25 per cent damage,' 

 and the last report of the season vras received from Maine on 

 June 16. where this insect was recorded as damaging the under- 

 ground stems of beans. 



The early potato planting season along the Atlantic coast was 

 characterized by hot and dry weather. Germination was slow and 

 conditions were possibly advantageous for the development of certain- 

 fungous diseases which, undoubtedly, were associated with the depre- 

 dations of, if not responsible for the damage attributed to the seed- 

 corn maggot. 



One of the most interesting features of the survey reports on 

 this insect were the independent reports from Maryland, Massa- 

 chusetts, and New Jersey, that infestations were far worse on 

 fields where meat scrap or fish scrap fertilizers were used. These 

 reports indicate that organic fertilizers of this class are attractive 

 to the adult seed-corn maggots. 



Figure 21 indicates the sequence of reports received relative to 

 the destructive abundance of this pest along the Atlantic seaboard 

 in 1921. 



The correlation of the weather conditions with insect outbreaks 

 was most forcefully illustrated during the past season by the very 

 unusual outbreak of this pest. The weather over the infested region 

 was characterized during the late winter and early spring by very 

 decided excesses of temperatures, January showing an excess of 

 nearly 3° F, February of 4^°, March of 10°. and April of 5^°. 

 This was accompanied by marked deficiencies in rainfall during 



