March, igoi.] DyAR : PyrALID l.A^iVi??, FROM FLORIDA. 19 



on or near the surface of the pround an oval, brittle cell of sand and 

 earth in which it transforms to a pupa within a few hours. 



The moderately stout pupa is of a Hght chestnut brown ; head, 

 thorax, wing and limb cases darker brown, finely rugose ; movable 

 segments finely punctured anteriorly with darker brown edge near 

 sutures, spiracles also darker brown. The pupa ends in two spines 

 about 0.7 mm. in length and is not fastened to the cocoon. Thorax 

 slightly compressed sideways. Length of earth-cell 15-17 mm., width 

 in the middle 10 mm. Length of pupa 12—13 ™ni-, width of 3d ab- 

 dominal segment, where the pupa is widest, 4.0-4.5 mm. 



First imagines of these broods appeared July 6th, the majority from 

 July 9th to July 12th. 



The plain color and design of Platysenta videns precludes marked 

 variation. The large material obtained by breeding shows fairly the 

 range of variation. The moths from wintering pupae expand 27- 

 32.5 mm.; those of the early summer brood 25-33 ™^"'^^- The sum- 

 mer form is throughout of a decidedly darker ground color of pri- 

 maries than the preceding one, even the fringe being often uniformly 

 blackish. The secondaries, which in the fall brood are in some cases 

 even plain whitish, show a tendency to form a more or less broad, 

 sooty, marginal band, sometimes shading beyond the middle. This 

 tendency to melanism in one brood is caused apparently by the favor- 

 able temperature and the excellent physiological condition of the 

 food-plant, which combined produce more vigorous individuals than 

 in the brood growing up in the fall, exposed to a waning food-plant 

 and frequently to the vicissitudes of the weather. 



DESCRIPTIONS OF SOME PYRALID LARV^ 

 FROM SOUTHERN FLORIDA. 



By Harrison G. Dyar. 



Margaronia bivitralis Guen.^ 



Larva. Head rounded, whitish green, ocelli black. Body slender, uniform, 

 segments 2-annulate, setae moderate. Transparent, the blood green, food dark green. 



* I learn from Prof. C. H. Fernald that the synonymy as given in the Smith list 

 and by Hampson is erroneous and that this species should be called Glyphodes sibil- 

 lalis ^zWi.^batesi YsXA^alilalis Hulst (nee. bivitralis Guen.). 



