8 BULLETIX 1076. U. S. DEPARTMEXT OF AGPJCULTURE. 



Aveaken and allow the leaf disks to drop to the surface of the water 

 (PI. I, A), Tvhere they soon j-ellow, decay, and sink. AVhen these ma- 

 ture floating leaves were examined it was found that in the center of 

 the disk, directly above the petiole attachment, a large number of 

 the leaves had a round opening leading to a cavity in the upper end 

 of the petiole (PI. IV. B, C). This ca^nty was shallow, seldom ex- 

 tending more than 2 centimeters into the petiole, and usually just long 

 enough to accommodate the larva and its cocoon. The entrance was 

 often surrounded and covered by a mound of soft brown frass pellets 

 (PL III. C). and frequently the surface tissue of the leaf in an irreg- 

 rilar area about it was scarred and eaten as if the larva after construct- 

 ing the cavity possessed still an appetite which it satisfied with the 

 nearest food at hand. 



In the case of the prepupal larvae or pupee the cavity in the petiole 

 is lined with a substantial white silk fabric, densest at the upper end 

 (PL IV. B) . The entrance is closed with a very accurately cut whitish 

 lenticular disk of plant tissue which fits closely and is sealed in with 

 silk. This disk lies usually a little below the level of the leaf surface 

 and is concealed by the frass until the latter is washed away or other- 

 vrise removed. This position of the pupal cavit3^ in the floating leaves 

 only, brings it below the water level. 



Welch (74. l^- 219-221) has well described the construction of this 

 pupal chamber and the feeding in connection therewith, and the be- 

 havior of the insects was found here to correspond closely with his 

 account. It is noteworthy, however, that in Lake Erie, where his 

 observations were made, the lotus leaves are always floating and not 

 held above the water, and their centers are higher than the periphery, 

 while at Kimberlin Heights the leaves are held 15 to 30 inches above 

 the water and are cupped with the margins higher than the centers, 

 so that they often catch rain or dew to the amount of several cubic 

 centimeters and hold it until it evaporates or is spilled by the sway- 

 ing of the leaves in the wind. The insect evidently prefers to con- 

 struct its cocoon in an aquatic situation and so seeks the old floating 

 leaves at the approach of maturity. Xever were young or partly 

 grown larvae found in the petioles, only those nearly mature and 

 l^robably in the last instar. Xeither are the young and erect leaves 

 attacked in this way ; only the old. floating ones. 



HABITS OF THE MOTHS. 



The only moths seen in the open were the few found in and near 

 the lotus plantation. Several of them were captured and found to 

 be predominantly males. Their flight was rapid and erratic, and 

 they were wary and not easily approached. They came to rest 

 usually on the lower side of a lotus leaf and often flew among the 

 jDetioles and beneath the canopy formed by the leaves 2 or 3 feet 



