TABLE 1. — Results of a typical experiment showing the overall attractiveness of differ- 

 ent -ultraviolet lamps resulting from differences in both "brightness" and "luminous 

 flux density. " 



Species 



Mercury - 

 vapor 



100-watt 

 CH-4 



BL 



15 -watt 



T-8 



BIB 



15 -watt 



T-8 



Agrius cingulatus (F. ) 



Agrotis malefida ( Guen. ) 



^grotis ypsilon ( Rott . ) 



Celerio lineata (F. ) 



Estigmene acrea ( Drury ) 



Feltia subterranea (F. ) 



Heliothis virescens ( F. ) 



Heliothis zea ( Boddie ) 



Laphygma exigua ( Hbn . ) 



Laphygma frugiperda (A. & S. ) . . . . 



Loxostege similalis ( Guen . ) 



Peridroma margaritosa ( Haw . ) 



Prodenia ornithogalli ( Guen .).... 

 protoparce quinquemaculata ( Haw . ) 



Protoparce sexta ( Johan. ) 



Pseudaletia unipuncta ( Haw . ) 



Trichoplusia ni (Hbn.) 



93 



114 



101 



38 



252 



139 



201 



1,277 



877 



174 



110 



144 



18 



167 



114 



198 



1,810 



1,042 



144 



391 



202 



1,031 



7,792 



4,587 



543 



2,245 



1,887 



185 



710 



564 



2,941 



7,259 



5,975 



82 



424 



222 



499 



2,522 



1,781 



51 



40 



38 



202 



512 



367 



2,119 



4,328 



3,069 



1,345 



1,568 



919 



Source: Pfrimmer, 1955, 

 Tallulah, Louisiana." 



batches of some species of Lepidoptera in three light traps at 



Studies of the effect of "photometric brightness" could be devised through the use 

 of sources of different brightness with appropriate areas exposed to create equal 

 densities of luminous flux over the test area. This admittedly would be rather difficult, 

 and the author is not aware of an instance in which it has been done. As a hypothetical 

 case, to compare the insect attraction of the "brightness" of the H100-A4 mercury- 

 vapor lamp (100-watt) with that of the 15T8 BL fluorescent lamp (15-watt), data on the 

 relative blacklight ultraviolet outputs of these lamps indicate that about three 15T8 BL 

 lamps would be required to give approximately the same "luminous flux" of 3650 A. 

 radiation (here properly expressed in "fluorens," a special term used for blacklight 

 measurements) as that of the H100-A4 lamp. 



28 



