544: PROCEEDINGS OF THE THIRD ENTOMOLOGICAL MEETING 



" I think myself that moths are not attracted to light from any 

 great distance and that they have to come near to a light in the course 

 of natural flight before they see it or come under its influence ; then 

 no doubt, the more brilliant the light is, the greater its power over those 

 species which will come to lights. 



" Another matter in which I am interested arid to which I have 

 been able to give a little time is the question of the survival of resting 

 Pink Bollworms in fallen bolls buried by ploughing the land for tte 

 crop following cotton. 



"An experiment of a simple nature was carried out in 1917 with 

 a view to giving us more information on this point. I enclose the 

 results in tabular form and other details on separate sheets as perhaps 

 they may be of some interest to you. 



" This experiment really requires to be done with more fineness and 

 attention to detail — for instance, it would be desirable to know the 

 temperature of the soil from day to day and the moisture content of 

 the soil and the influence on these factors of the different crops grown. 

 Again, if one could devise some means of keejjing track of all — or at any 

 rate most of — those Pink Bollworms which one Icnows one has buried in 

 the bolls but which one never sees — or rather sees so few — figure in one's 

 records, it would be a great gain. It is not possible to cover in a plot 

 because by so doing one cuts off to a large extent the influence of the 

 sun — a most important factor. No doubt many of the " missing " 

 larvas have left the bolls, made their way to the surface, and crawled 

 away, but I do not feel by any means confident that this is the explana- 

 tion of the sudden drop in the number of the larvae surviving in buried 

 bolls during the period end of May to end of June and subsequently. 

 It is possible, and personally I think it quite j^robable, that at this 

 season many larvse are killed by the dry soil being heated up to a 

 temperature fatal to the Pink Bollworm by the sun — at any rate to a 

 depth of 5 cm. if not to 10 cm. One might say, as there are no 

 records of dead larvse being found in the bolls, that therefore it is more 

 probable that they had left the bolls to pupate on the surface than that 

 they had remained to be baked alive. But as a matter of fact one 

 cannot employ this explanation since it is exceedingly difficult to 

 spot remains of dead Pink Bollworms when examining bolls which have 

 been buried and are therefore more or less rotten and much discoloured 

 — the dead Pink Bollworms being in the same state. 



" The presentation of records showing the large numbers of live 

 larvse present in bolls kept in the laboratory on certain dates is also 

 inconclusive as evidence from " the death by heat " explanation rather 

 than the " evacuation of the bolls to pupate " explanation, because 



