STUDIES ON THE FLIGHT OF NOCTURNAL 

 LEPIDOPTERA^ 



Bv William C. Cook 



The data here presented were accumulated during tlie summer of 

 1920 at University Farm, in connection with general ecological studies 

 of the Noctuidae of the cutworm and army worm groups, including 

 the genera Agrotis, Septis. Sidemia, Euxoa, Feltia, Cirphis, Folia, and 

 their near relatives. Many of these species are of considerable eco- 

 nomic importance in the state because of their attacks on farm crops. 

 The discussion will be limited in this paper to two questioris. seasonal 

 and meteorological relations of the adult moths. 



The only previous work on the flight of ^linnesota Noctuidae is 

 that of Lugger ( 1 )- which gives a list of species captured, the duration 

 of their flight, and their abundance as "rare," "common," or "very com- 

 mon." In 1919, collections were made by sugaring about twice a week 

 at University Farm, but the numbers so obtained were not sufliciently 

 large to give data of any accuracy, so in 1920 it was decided to use 

 more systematic methods of collection. As the moths are very strongly 

 attracted to sugar, the writer determined to try a form of bait trap 

 similar to that used in Europe against the vine moths (Dewitz, 2). In 

 this instance six-inch flower pots were used. They were varnished 

 on the inside and the hole in the bottom w^as plugged with a cork. The 

 pots were then suspended by strings from the apple trees or the station 

 orchard, at a height of from three to three and a half feet, and filled 

 with a ten per cent solution of molasses in water. This fermented 

 within a few hours and remained attractive for three or four days, 

 when it was renewed by the addition of about half the volume of fresh 

 solution. The moths were attracted in large numbers and drowned 

 in the solution, no provision for retaining them being necessary. Even 

 the larger species of Catocala were thus caught. The moths were col- 

 lected each morning, with the exception of about ten days noted below, 

 and the various species separated and counted. 



The use of bait traps for the control of Noctuidae is by no means 

 new. having been practised in Russia for controlling Euxoa scgcium 



1 Puhlisheil with the approval of the Director as Paper No. 25S, of the .Journal 

 Series of the Minnesota Agricultural Experiment Station. 



2 Numbers in parentheses refer to literature citeil. See end of paper. 



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