476 



Journal of Agricultural Research voi. xvm. No. 9 



held the charge of sodium cyanid and was provided with a wire-cloth 

 cover having at its center a square of wood bored to receive the stem 

 of a small glass funnel. About five minutes were required to place the 

 plug of cotton, pour the 25 per cent sulphuric acid into the glass tube, 

 remove the dead moths, introduce a fresh charge of cyanid, and remove 

 the tampon from the cone. 



The trap was crated so that the door could be wedged tightly and the 

 trap be made easy to handle. 



Fig. I.— Light trap; A, opening for cone; BBBB, plates of glass; C, glass tube to convey acid; D, glass 

 jar to hold cyanid; E, glass funnel. 



RESULTS OF EXPERIMENTS 



As has been stated, collections were made on 28 full nights between 

 May 14 and September 13, The total of 3,152 moths recorded for that 

 period embraces sixty-odd species. Of this total, 2,200, or 69.8 per 

 cent, are males; and 952, or 30.2 per cent, are females. Table I gives 

 an itemized account of the species, the numbers taken of each sex, and 

 the percentage of males and females. In two species, Noctua c-nigrum 

 and Euparthenos nubilis, the two sexes are equally represented; and of 

 those species of which at least five individuals were taken, three show 

 a preponderance of females. 



