Februar\% '21] fluke: pea moth in Wisconsin 95 



sular district as the codling moth is to the apple growers of Wisconsin. 

 As many as 2 to 50 per cent, of the pods are infested each year, but unlike 

 the codling moth there is as yet no known efficient remedy to check it. 

 Until just recently the pea moth of this country was known as the 

 European pea moth — Laspeyresia nigricana Stephens, but according 

 to Heinrich^° our species is distinct and is now known as Laspeyresia 

 novimundi. Except where indicated the data, here presented, covering 

 life history studies were gathered during the 1920 season. 



Distribution 



Mr. Heinrich suggests that "if novimundi is not a native species that 

 has gone over to the pea from some wild legume, it has probably been 

 introduced from the Orient." The first report of the destructiveness 

 of a moth similar to if not the same as novimundi in this country came 

 from Canada. Fletcher in 1895 reported it injurious in Ontario, Quebec, 

 and the Maritime Provinces. In 1909 Chittenden J reported the occur- 

 rence of the pea moth in Michigan. 



The pea moth has been known to be destructive in Wisconsin for the 

 past 15 years. One farmer in Brown County declared that he knew 

 the insect as an enemy of peas some thirty years ago. From this evi- 

 dence it is possible that it has been in the borders of the United States 

 since about 1890. 



Characteristic Injury 



The larvae of the pea moth injure the peas by boring into the pods 

 and feeding upon the growing and ripening peas within. The young 

 larv^ae make very tiny holes when entering the pods and these entrances 

 are not observable after the larvae are within. The young feed upon 

 one or all of the peas in each pod. Frass soon accumulates and this is 

 webbed together and forms a filthy mass around the peas. Upon 

 opening the pods the larvae are nearly always foimd within these masses 

 and feeding upon the seeds which are near. There is no indication from 

 the outside that the pods are infested; they must be opened to detect 

 the presence of the worms. 



Larvae have been found in the majority of cases in partly grown pods ; 

 however, numerous very young larv^ae were noticed in nearly ripe pods, 

 even though there were immature pods still on the vines. 



Food Plants 



If the pea moth in this country is a native species and indications at 

 present are that it is, another food plant other than cultivated peas 

 will probably be found. At present novimundi is known to attack only 



