376 FIEST ANNUAL REPOET OF THE STATE ENTOMOLOGIST. 



terminal half of its wings still encased in their sheaths, and with no 

 movement other than a tremulous motion of the feet. It then turned 

 itself around for a few times and moved several steps over the leaf, 

 when it took position with its head directed downward, its front pair 

 of legs holding to the leaf and the others detached. Slowly the 

 abdomen was withdrawn from its encasement and the colorless wings 

 from their sheaths. Soon the yellow stripes of the wings began to 

 appear and insensibly to deepen. As yet there was no indication of 

 the black stripes traversing the thorax and wings, or of the black of 

 the membranaceous wing-tips. 



In twenty-five minutes from the observed commencement of the 

 transformation (at 1 o'clock as noted), the wing-tips had fully ex- 

 panded. The time occupied in the disengagement from the pupal case 

 was not noted ; it could not have varied much from five minutes. At 

 1 h. 15 m., there were indications of the black stripes in a duskiness 

 of color. At 1 h. 40 m., the lines had deepened to a leaden hue and 

 the antennre were dark. At 2 o'clock, all the stripes, the small spot 

 toward the wing-tip, and the tip, had become blackish, 'and the bands 

 on the legs were showing. When next observed, at 3 o'clock, the 

 stripes were glossy jet black, and the mature coloring throughout had 

 been assumed. 



"While change of color frequently attends insect meltings, and usually 

 to a greater or less degree the larval molts of the Lepidoptera, it is rare 

 that so marked a change as that above noted, ranging from white to 

 black, can be observed, and in so brief a time.* 



Continuation of the Attack. 



The latter part of June (29th), the insects were still quite destruct- 

 ive in my garden, and had injured and disfigured a large number of 

 plants, although effort had been made to check their depredations by 

 daily killing numbers of them by hand. On July 16th, they were obr 

 served feeding on geraniums, the foliage of which they were rapidly 

 destroying by the infliction of hundreds of unsightly and devitalizing 

 blotches upon each leaf. The latest period of their continuance, ow- 

 ing to my subsequent absence from home for several weeks, was not 

 ascertained 



Life-History Incomplete. 



It will be seen from the above account that our knowledge of (lie 



*A thorough discussion of color in insects — its nature, source, production, kinds, 

 changes, mimicry, etc., and also of pattern — its origin, cause, purpose and variability — 

 presenting the most advanced knowledge upon these interesting points — may be found in a 

 paper " On the Color and Pattern of Insects" by Dr. H. A. Hagen, published in the Pro- 

 ceedings of the American Academy of Arts and Sciences, vol. xvii (N. S. ix), 1882, pp. 234- 

 267. 



