BIOLOGY OF THE LOTUS BORER. 5 



winter quarters in the fall until the young larvge of- the first generation 

 appear on the leaves in June is unknown, and the outline here fiven 

 for that period is hypothetical. 



FEEDING HABITS ON THE LEAVES 



After hatching, the larvse feed gregariously for a time, gnawing 

 oif the epidermis of the leaf in irregular patches, first protecting 

 themselves with a shielding network of brownish silk stretched 

 across some slight concavity of the leaf or producing such a concav- 

 ity by its tension. They soon scatter, each forming a similar retreat 

 of its own (PI. II, F), either in the center of the leaf above the peti- 

 ole attachment or around the margin where the edge is easily drawn 

 up a little to form the necessary free space beneath the web (PI. Ill, 

 A, B). Less often a larva locates on the blade between the center 

 and the margin. Protected and partially screened by the webs, the 

 larvse strip the epidermis from'" the leaf, those at the center in a 

 more or less radiate pattern and those at the margin following the 

 periphery. They extend their retreat as they exhaust the food sup- 

 ply and occasionally prolong the feeding area irregularly inward 

 toward the disk of the leaf. At no stage is the entire substance of 

 the leaf eaten. The areas from which the epidermis is stripped soon 

 turn brown, dry, and fall out, leaving the leaf lacelike along the 

 margin (PL III, D) and generally tattered in ajopearance. 



Although at Kimberlin Heights no larvse were observed in the 

 act, it is evident that they moved about from leaf to leaf and from 

 one portion of a leaf to another. Small feeding webs were often 

 found uninhabited, and tiny larvse were found in retreats evidently 

 occupied previously by much larger ones. Where several larvse oc- 

 curred on one leaf the retreats often overlapped around the margin, 

 giving the effect of a large retreat occupied by several larvse. No 

 evidence was found of the larvse swimming from one leaf to an- 

 other as was observed by Welch in Lake Erie. The leaves were in 

 almost every case contiguous to each other, especially when swayed 

 by the breeze, and no need for such a means of locomotion was ap- 

 parent. Then, too, the old floating leaves, loose from their petioles, 

 drifted back and forth across the pond before the wind and, work- 

 ing in among the standing leaves, formed pontoon bridges between 

 the petioles, (PI. I, A.) 



One exceptional instance was observed in which a leaf standing 

 somewhat by itself but not especially isolated was found with a 

 series of six holes in the petiole between the blade and water, each 

 of which opened into a short cavity containing a fully mature 

 larva evidently preparing to pupate. Not another larva was found 

 in such a location, and this case can only be explained on the ground 



