﻿OF THE STATE ENTOMOLOGIST. 129 



mise. The specimens from which the figure was made were destroyed 

 with the Walsh cabinet in the Chicago fire; but I have a very distinct 

 recollection of them, and judging from the nature of the eggs of 

 PertJiostoma^ with which I am familiar, there is little doubt in my 

 mind that these supposed eggs of Corydalus really belong to Belos- 

 toma grandis, (Fig. 33) which is the only aquatic Heteropterous insect 

 of sufficient size to lay them. 



THE YUCCA EOW^n—Megathymus yuocoe (Walker.) 

 [Ord. Lepidoptera ; Fam. Hesperid,e ] 



Havinff, during the year, reared this interesting butterfly from the 

 egg, so as to watch its growth, I can supplement the article published 

 a year ago by stating, positively, that there is but one generation 

 annually, and that the characteristic glistening powder that covers 

 the full grown larva, is not secreted till toward the last molt. The 

 larva referred to on p. 181 of my Eighth Keport, as being kept in a tin 

 box, and fed solely on the leaves, lived till the 25th of September. It 

 formed a perfect cylinder of silk and excrement around the bottom of 

 the box, fastening thereto the ends of the cut leaves, so that the cylin- 

 der was necessarily broken each time the leaves were changed. This 

 specimen went through no less than seven molts at irregular inter- 

 vals of 10, 11, 24, H, 61, 15 and 21 days respectively. It changed but 

 little in appearance, except in becoming somewhat paler, after the 

 second molt, and died when about three-fourths grown — death result- 

 ing, I think, more from the mould that formed from the excrement, 

 and which it was impossible to prevent, than from the nature of its 

 food. It is doubtful if so many molts are suffered in more natural and 

 healthy conditions. 



Another specimen that entered a Yucca plant in the garden of 

 my friend, Dr. G. Engelmann, throve admirably, extending over a foot 

 beneath the ground, and attaining full growth by the end of Septem- 

 ber ; while a third, in a potted Yucca aloifolia in-doors, hollowed out 

 the entire root, pupated on the 26th of January, 1877, and gave out 

 the imago on the 25th of the following month. 



