1224 



AMERICAN FORESTRY 



Papilio ajax marcellus — male. Walshi is the winter 

 form of ajax, the "chrysalids which have been exposed 

 to the cold of the winter" produce it ; "the black bands 

 of the wings are narrower and a trifle paler than in the 

 other forms, the tails of the hind wings tipped with 

 white, and the crimson spot on the inner margin near 



Fig. 5. FEW BUTTERFLIES IN EASTERN UNITED STATES CAN 

 RIVAL IN BEAUTY THE FAMOUS "SWALLOWTAILS;" AND OF 

 ALL THAT GROUP THERE IS NOT A HANDSOMER SPECIES THAN 

 THE ONE HERE SHOWN, WHICH IS WIDELY KNOWN AS THE 

 "ZEBRA SWALLOWTAIL" 



Butterflies of this zebra kind long puzzled the entomologists, for the reason 

 that they_ were found to be seasonally polymorphic. The one here shown 

 is the Ajax — a most remarkable insect. 



the anal angle forming a conspicuous bent bar." In 

 flight, this butterfly has the appearance of being white, 

 banded with black (as in the cut for the under side), with 

 the wings emarginated with a broad band of black ; the 

 red spot is quite conspicuous. It would seem that in 

 certain localities these various types of Papilio ajax 

 intergrade, making it a bit difficult sometimes to define 

 and name them with absolute certainty. In any event, as 

 it does a tree no good to have its leaves eaten up by 

 caterpillars, and as the Papaw is a tree of some value 

 along the streams that course through our forests, the 

 caterpillar of this handsome butterfly must be considered 

 in the light of an insect inimical to it. 



Speaking of the early stages of the genus Papilio, 

 Holland says that "the eggs are somewhat globular, flat- 



tened at the base, and smooth. The caterpillars are 

 cylindrical, smooth, fleshy, thicker in the anterior portion 

 of the body than in the posterior portion, and are always 

 provided with osmateria, or protrusive scent-organs, 

 which, when the larva is alarmed, are thrust forth, and 

 emit a musky odor, not highly disagreeable to the human 

 nostrils, but evidently intended to deter other creatures 

 from attacking them. The chrysalids are always attached 

 by a button of silk at the anal extremity, and held in 

 place by a girdle of silk about the middle. The chrysalids 

 are, however, never closely appressed to the surface upon 

 which pupation takes place." 



It is surely very remarkable how the caterpillar can 

 attach the delicate little girdle of silk that goes about 

 its waist, or the "button" at its abdominal extremity, 

 during the transformation performed through pupation. 

 It has not been the writer's fortune to observe this up 



Fig 7. WE HAVE HERE AN ENEMY OF THE BLACK OAK— A 

 BEETLE KNOWN AS THE BROAD-NECKED PRIONUS {Prionus lali- 

 collis) 



During the first two weeks in July, this big, black Prionus emerges at 

 twilight, and may frequently be captured around the street-lights of 

 eastern cities. This is a Washington specimen. 



to the present time, notwithstanding the fact that many 

 papilionian larvae have been kept by him during their 

 transformation to the pupa stage, and, after that, until 

 the butterflies emerge from them. The suspending girdle 

 is invariably adjusted with the greatest care, in the same 

 place, with the head of the pupa above, and the very 



