STUDIES OF THE LIFE HISTORY OF 

 NOMOPHILA NOCTUELLA. 



W. p. Flint. 



This insect, one of the common and widely distributed 

 species of the world, is of considerable economic importance, 

 but for some reason seems to have received but little attention 

 from American entomologists. 



In 1919 the insect became so abundant as to seriously 

 damage several newly seeded fields of sweet clover on the 

 Experiment Station farm at the University of Illinois. Nearly 

 every year injury by this insect is reported from some localities 

 in Illinois. 



In 1872 A. S. Packard (Ann. Lye. Nat. Hist., N. Y., X, 

 pp. 258-260) gave a brief account of the insect. E. P. Felt 

 (Can. Ent., V. 25, No. 5, pp. 129-135; 1893) gives a full descrip- 

 tion of the different stages of the insect, together with observa- 

 tions on its feeding habits and the number of generations 

 occurring in New York. Judging from collections made in 

 trap cages, he estimated that three generations of the insects 

 occurred annually in the vicinity of Ithaca, N. Y. 



So far as the writer is able to learn, no detailed observations 

 of this insect have been carried through, even for one season. 

 For this reason an attempt was made to ascertain the facts 

 regarding its life history in central Illinois. 



Nearly full grown larvae were taken from the field June 6, 

 1919, and confined in breeding cages in an outdoor screened 

 insectary, where conditions were practically the same as in 

 the field. The larvse were placed in large tower cages with 

 plants of red and sweet clover. 



The insect was carried through three generations during 

 the remainder of 1919, adults appearing first on June 19, again 

 July 28, and September 11. Larvse hatching from eggs laid 

 by the adults appearing on the latest date were from one-fourth 

 to nearly full grown on October 30, when freezing weather 

 prevented any more feeding for the season. Adults were 

 noted in the field the following spring on March 21, during a 

 period of unusually high temperatures. This period of warm 



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