Academy of Science. 



under sides of the leaves. When first hatched the larvas are 0.13 of an incli in 

 length, and black. After the first moult, the head is dark brown and the abdomen 

 dusky. The food plants are the willow and cottonwood. Like the larvae of the 

 Colorado potato beetle, they are voracious feeders, a comparatively small number 

 being sufiicient to defoliate a tree of considerable size, and were they as numerous 

 as the noted enemy to the potato vine, the damage done by them would be of no 

 little moment. They eat int(t the side of the leaf, leaving the stem and veins naked. 

 The first lot of beetles was raised from the willow, entering the pupa July 25th, and 

 emerging July 30th. 



On August 12tli we captured two litters of larvae upon the cottonwood, which had 

 evidently just hatched, judging from the uneaten condition of the leaves upon 

 which they were found. These entered the pujia August 20th, and came forth per- 

 fect beetles August 26th, thus making the time required for their total transformation 

 about fifteen days, and establishing the certainty of at least two broods in a season. 

 The most prominent peculiarity of the larva consists in the white fleshy organs 

 which are thrust out from the tip of the abdomen and from' the dark-brown tuber- 

 cles on the sides of the body. Wliat may be the exact use of these organs, especially 

 of those upon the sides of the body, we are unable to tell. They find an analogy in 

 the organs of the Ajax butterfly [Papilio Ajax), and the Asterias butterfly {Papilio 

 Asteriua). Like the organs of these butterflies, they give forth a strongly-scented 

 secretion, and from this we might infer that they were a means of defense. One 

 thing is certain, however, that the organ from the abdomen is made use of in pupa- 

 tion, for, this being extended, it is glued fast to the under side of some twig. The 

 larva then only partially sheds its skin, one-fourth of the body remaining within 

 the old skin, to which it is stuck fast. Thus, like the chrysalides of many butter- 

 flies, the pupse remain suspended until the imagos come forth. The following are 

 descriptions of three of the different stages of the insect: 



Egg. — Length, O.OG in. Diameter, 0.015 in. Elliptical in shape, and transparent 

 green in color. 



Lakva. — Length, 0.50 in. Circumference, 0.35 in. Head dark brown, circular, 

 and much smaller than the body. General color of body light yellowish brown; 

 feet dark brown, with an encircling band of light brown near the base; a convexo- 

 concave patch of dark brown on the top of the first thoracic segment; a short tuber- 

 culous spine of dark brown on each side of the second and third thoracic segments, 

 from which is projected a white, fleshy organ; a sub-dorsal row of dark brown 

 spots, two spots to each segment in the second and third thoracic segments and one 

 in the remaining segments, the spots of the two rows uniting in the eleventh, 

 twelfth, and thirteenth segments and forming one oblong spot; below this, extend- 

 ing from the fifth segment to the last, i&a row of dark brown tubercles, one tubercle 

 to each segment; a lateral row of dark brown spots, one spot to each of the last 

 nine segments, below which is a row of dark brown tubercles with one tubercle to 

 each segment, except the second and third thoracic, which have two each; below 

 the latter are two rows of dark brown spots, one spot to each segment, and finally a 

 ventral row of dark brown elongated sjjots, one to each segment; abdomen provided 

 with a white, viscid, fleshy organ, capable of being extruded. 



Pupa. — Length, with the old skin of the larva, 0.50 in. True length, 0.31 in. 

 General color, light brown; head, centre of thorax, and feet, dark brown. 



