28 TWENTY-THIRD REPORT ON THE STATE CABINET. [160] 



IV. NOTES ON PIERIS OLERACRA (HARRIS). 



Fifty eggs of this butterfly were collected at Schoharie, 1ST. Y., on 

 the 22d August from a small patch of turnips of perhaps twenty square 

 feet. A small bed of cabbage plants adjoining, yielded none of the 

 eggs, indicating a marked preference by the insect for the former plant. 



With few exceptions, the eggs were placed on the under side of a 

 leaf, so near the edge as to render it probable that the butterfly in 

 ovipositing alights on the margin of the upper surface, and bends her 

 body over its edge to place her egg on the less exposed under surface. 

 Usually but one occurs on a leaf, but occasionally two or three are 

 found so near together, as to indicate their having been deposited at 

 the same time. 



The eggs are ovoid in form, corresponding with the familiar repre- 

 sentation of those of JPieris brassica of Europe ; they are of a yellow- 

 green color, and measure .047 of an inch in length (average of three), 

 with a diameter of about one-third their length. They are fluted 

 longitudinally, presenting fourteen ribs in two specimens examined 

 and sixteen in a third, which unite in about half the number near the 

 apex. The ribs are sharp-edged, while the intervening flutings show 

 about forty transverse lines. 



Ten eggs disclosed their larvae during the night of August 24-25. 

 The larvae were pale green, cylindrical, with some short, whitish hairs, 

 and measured .075 of an inch long. 



The emergence of a larva from the shell was observed, and for a half 

 hour it was seen to be vigorously plying its black-tipped mandibles 

 on the interior surface near the apex, before it effected an opening. 

 The opening made with so much labor was rapidly enlarged by the 

 larva eating a sufficient portion of the shell to permit its egress. 

 Immediately upon having wholly withdrawn itself, it resumed its 

 feeding upon the shell, nearly all of which it consumed. It increased 

 rapidly in size ; on the morning of the 26th (twenty-four hours after its 

 disclosure) it measured .13 of an inch in length. 



On the 27th p. M. four larvae had molted for the first time, and four 

 more on the 28th A. M. (two were missing.) 



On the morning of the 30th the larvae were found to have molted for 

 the second time ; probably some of the number underwent their change 



