514 



DR. L. H. GOUGH. 



These observations make it advisable, if borne out by another season's records, 

 to reconsider the final date up to which screening is compulsory. Moths emerging 

 in September might, if left to find their way back to the fields, effect serious damage 

 on the later part of the crop. The cotton of Northern Behera, which by reason of 

 its position in the north is late, is on account of its vicinity to Alexandria liable to 

 become attacked by part at least of the millions of moths emerging in the seed-stores 

 of that town, given suitable weather conditions. 



This record of 54,000 moths caught by traplights during the year ought to be 

 sufficient to disprove Busck's* statement that the moths are not attracted to light ; 

 the evidence yielded by Table XXIV, which is a copy of the daily records composing 

 part of the series whose summary in weeks has been given in Table XXIII, is however 



Table XXIII. Showing the Weekly Numbers of Gelechia Moths caught by a 

 Trap-light in a Cotton-seed Store at Alexandria. 





Number of 





Number of 



Week commencing. 



moths 



Week commencing. 



moths 



• 



caught. 





caught. 



1917 





1917 





June 21 



176 



Dec. 20 



12 



„ 28 



187 



„ 27 

 1918 







July 5 



248 



Jan. 3 



1 



„ 12 



837 



„ 10 



2 



„ 19 



1120 



„ 17 



3 



„ 26 



144 



„ 24 







Aug. 1 



41 



„ 31 



4 



„ 9 



123 



Feb. 7 



6 



„ 16 



69 



,. 14 



7 



„ 23 



19 



„ 21 



4 



„ 30 



691 



„ 28 



2 



Sept, C 



21699 



March 7 



5 



„ 13 



16843 



» U 



2 



,. 20 



7340 



„ 21 



5 



„ 27 



232 



„ 28 



10 



Oct. 4 



194 



April 4 



20 



„ 11 



416 



„ 11 



38 



„ is 



235 



„ is 



39 



„ 25 



737 



,. 25 



20 



Nov. 1 



212 



May 2 



29 



„ 8 



1128 



9 



45 



„ 15 



1166 



„ 16 



58 



„ 22 



26 



„ 23 



40 



„ 29 



25 



„ 30 



56 



Dec. 6 



14 



June 





„ 13 



5 



1 9 





conclusive. It will be observed that during the three weeks in question the light 

 was not burning on two nights, and that in consequence the catch fell from several 

 hundreds or even thousands to 8 on the first and to 1 on the second occasion, thus 

 supplying the necessary controls to prove that the attraction to the trap was the light 

 and not the smell of the paraffin. Whether the windows of the store were left open 



*Jour. Agric. Research, Washington, 1917. 



