46 



attempts are made before an egg is laid. A strong, healthy moth, 

 however, does not often fail to lay. From one to two seconds are 

 usualh^ required for each deposition. When possible the body is held 

 either with the head up or horizontal when ovipositing, although 

 when feeding the body may be turned at almost an}^ angle without 

 apparent inconvenience to the moth. 



In order to obtain the foregoing data regarding oviposition on cot- 

 ton some 34 moths were followed in the field at dusk, and the portion 

 of the plants upon which eggs were laid was carefully noted at each 

 deposition. Most of these records were made between 7.15 and 8 

 o'clock in the evenings during the first week of August. At that time 

 the moths were so common that the greatest difiiculty in following 

 them was to avoid confusion of the observed moth with others in close 

 proximity. 



The appended table gives the individual records of a few of the 

 moths, together with the totals for the entire lot of 34 moths. 



Table X. — Distribution of eggs on the different 2^arts of the cotton plant. 



Part of plant. 



Lower surface of leaves . 

 Upper surface of leaves. . 



Squares 



Growing tips , 



Flowers , 



Stems , 



Petioles 



Bolls 



Weeds 



Objects on ground 



Dead leaves 



Individual records of 11 moths. 



7 



7 14 

 12 

 4 

 2 11 



Total eggs laid 42 



Time observed, in minutes. 

 Number of plants visited . . . 



60 



84 

 31 

 149 



139 

 65 

 120 



Total 

 of 34 

 moths. 



191 



194 



326 



46 



110 



64 



29 



120 



20 



21 



20 



1,141 



474 



1,175 



Per 



cent. 



16.7 



17.0 



28.5 



4.0 



9.7 



5.6 



2.5 



10.5 



1.7 



1.8 



1.7 



In all, the deposition of 1,141 eggs is recorded upon 1,175 plants. 

 The very close correspondence in numbers might suggest that one egg 

 is usually laid to a plant by each moth, but this is not true, as many 

 receive none at all and others a considerable number. A total time of 

 28,440 seconds was occupied, which gives a probable average of twenty- 

 five seconds between two successiv^e depositions, and allows for the ovi- 

 position of some 280 eggs each evening during a period of two hours. 

 This is not far from the average obtained from observations on moths 

 laying in confinement. While this may be a good general average, it 

 is inapplicable to any special case on account of the great individual 

 variation among different moths. 



DistrihxLtioii of eggs on cotton. — More eggs are laid upon the squares 

 than upon an}- other part of the plant except the leaves, although onl}^ 

 28.5 per cent of the entire number are so placed. The fact that 



