PROCEEDINGS OF THE THIED ENTOMOLOGICAL MEETING 481 



tlian the dead bolls ; both of these two classes of bolls are emitting 

 their maximum numbers of long-cycle moths in July and August, that 

 is, at the very time when the cotton plant is most ready to receive them. 

 What happens to the moths of the winter generation emerging in April 

 and May is yet unknown. Unless they can manage to survive into 

 June it would seem probable that they must die without giving rise 

 to new descendants, unless they utihze ohroe. Investigations are 

 planned by which it is hoped to acquire information on these points. 

 <See Table IX). 



The moths hide away in dark places during the day-time, and are 

 then very difficult to find. In seed stores where one knows that immense 

 quantities of living moths must be present, it is very difficult to find 

 them. However, by turnitig over boards, raking in the seed, and 

 examining between sacks, it is usually possible to find specimens. Dead 

 moths are most abundant on the sills of moth- screened windows and 

 under the skylights in seed stores. In the fields they are equally well 

 hidden, and more difficult to find as there are more hiding places for 

 them. When disturbed in the day-time they very rarely fly, but scurry 

 away and hide as soon as any dark cover or crack presents itself. At 

 night they are attracted to artificial light, but according to Willcocks' 

 experiments not sufficiently so to allow light-traps to be of practical 

 use as a remedy. The attraction to light is however quite marked, 

 and is utihzed by us in Cairo in obtaining our emergence results. In 

 our large breeding shed3, and also in one of the largest seed stores at 

 Alexandria, we trap the moths, which would otherwise be almost impos- 

 sible to find, in this way. An electric light of 20 candle-power 

 is suspended about 15 cm. above a basin of water, on whose surface 

 there is a thin film of petroleum. We also employ a similar trap in 

 the open in our garden to inform us of the frequence of the insects out- 

 side our experiments. Our recorded catches by this method run to 

 71,372 Pink Bollworm moths (see Table X). The series of records from 

 the Alexandria seed store are particularly interesting. Here, during a 

 period when the insects were being caught by the thousand, the light 

 failed on two occasions. The moths also failed to get caught on those 

 same occasions (see Table XI). This proves that it was not the 

 petroleum, nor the water which was the principal attraction, but the 

 light itself. Against this I must again quote Busck {loc. cit., p. 355) 

 " From very many varied and repeated observations under different 

 conditions it may be definitely stated, notwithstanding the many other 

 statements to the contrary, that Pectinophora gossypiella is not at- 

 tracted to light, but is, on the contrary, shy of all light, natural 

 and artificial." 



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