1919] Welch: Pyraiista Penitalis • .' 215 



of the mass was unknown, the length of the egg-stage could not 

 be determined. The young larvae, at the time of hatching, 

 were about 1.5 mm. long. They immediately began feeding 

 upon the leaf in the vicinity of the egg-mass, consuming the. 

 upper surface in the characteristic manner. The surface 

 webbing, described later, appeared very soon, subsequent 

 development and activities continuing in the fashion normal 

 for the species. 



The difficulty of finding the egg-masses is quite puzzling 

 since the writer examined hundreds of Nelumbo leaves and the 

 amber color of the egg-mass against the green background of 

 the leaf, if that be the usual place of oviposition, should make 

 detection rather easy. Furthermore, the writer observed 

 dozens of leaves each bearing very small larvae which, it would 

 seem, rnust have emerged from eggs deposited very near by, 

 but no indications of old egg-masses were detected. 



Chittenden found a considerable number of these larvae 

 boring into the canes of raspberries and lil^ewise, to some 

 extent, in the stalks of corn. However, he states (p. 455), that 

 "there is no evidence that the species feeds on either healthy 

 corn or r,aspberry, although it feeds on the pith to a considerable 

 extent, but ori the contrary develops chiefly upon Jotus and other 

 aquatic or semiaquatic plants and enters cornstalks and the 

 cut ends of raspberry canes chiefly as a retreat for passing the 

 winter and for subsequent transformation. " This statement is 

 not entirely clear. It seems to imply that corn and raspberry 

 may not be affected unless in some unhealthy /condition. It 

 also appears to suggest that these larvae pass their early develop- 

 ment in aquatic situations and then some of them migrate 

 to certain terrestrial plants in order to find a hibernation place. 

 Chittenden has tried to formulate "an approximate life history" 

 from the fragmentary bits of available information and sug- 

 gested that the larvae constitute the hibernation stage; that the 

 adults begin emerging in March ; that larvae appear in due course 

 of time and feed until late in August when they complete their 

 growth, seek a convenient winter retreat and hibernate. Such 

 a statement suggests only one generation per year. 



Certain observations of the writer do not seem to corroborate 

 the above-mentioned inferences. It was not possible to 

 determine the hibernation stage and it may be that some of the 

 larvae, in late autumn, do migrate to shore and find hibernation 



