BIOLOGY OF THE LOTUS BORER. 9 



above the water. No data are available as to the lenath of life of 

 the moths in the open. A series of reared moths retained alive in tin 

 boxes supplied with a wad of wet cotton furnished the data on this 

 point contained in Table I. 



Table I. — Length of life of reared moths in confinement {in terms of days). 



Sex. 



Maxi- 

 mum. 



Mini- 

 mum. 



Average. 



Number 

 of moths 

 averaged. 



Male 





14 

 13 



2 

 3 



6.77 

 7.72 



27 

 43 



Female 









THE EGG. 



The act of oviposition has not been observed, but very probably 

 occurs toward dusk or at night. Nothing was known about the 

 egg until Welch (i^, p. 21 4-) observed and rather incompletely de- 

 scribed it. The authors have found numbers of the masses (PL 

 II, D) at various times, and as their observations differ in some 

 jDoints from those of Welch a description in somewhat greater 

 detail is included. 



The egg: Thin, flat, elliptical in outline. 0.9S millimeter long, 0.56 millimeter 

 wide, chorion finely reticulated with narrow elevated lines -and in addition finely 

 longitudinally wrinkled, dingj" yellow or amber color when laid, soon develop- 

 ing a narrow darker border and a paler opaque central area. They are laid 

 in thick circular masses of 40 to 80 eggs, 2.5 to 3 millimeters in diameter and 

 0.47 millimeter thick, each egg overlapping its predecessor shingle-fashion, about 

 three-fourths covering it and lying at an angle of approximately 45° with 

 the leaf surface, the mass being dingy yellow in general color. The larva 

 leaves the egg through a transverse slit in the exposed end. After hatching 

 the mass is dirty gray in color, somewhat shining, and much flatter than be- 

 fore. It is then very loosely attached to the leaf and easily removed by a 

 slight touch. 



The writers failed to note any matrix such as Welch describes. 

 They did. however, note the frequent absence of the empty egg mass 

 on leaves bearing very small larvae, but attributed the fact to the ease 

 with which the empty egg mass is washed or blown from the leaf. 

 A number of the egg masses were found, both unhatched and empty, 

 and one in which the eggs were parasitized. They seem to be placed 

 at any point on the upper surface of the leaf and when present on an 

 unblemished leaf are easily seen. 



It has. of course, been impossible to determine how many eggs are 

 normally laid by a female in the open. The possibilities are indi- 

 cated, however, by results obtained from reared moths confined in tin 

 boxes and supplied with moisture. Of -13 females so confined only 

 15 oviposited. The number of eggs produced by an individual varied 

 from 9 to 504. with an average for the 15 of 1-13 eggs. These moths 



