442 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



The Cosaus after being pinned is very restive, especially while depositing her ova 

 and by the constant motion of the ovipositor in endeavoring to extrnde the ova. The 

 loose abdominal scales are removed and attached to the eggs by the moist viscid 

 flnid with which they are covered, and which often gives them the appearance of 

 being clothed with scales. A few of the ova collected this season have this appear- 

 ance, but a strong lens exposes the true condition. C. ceiitei'ensis is not so prolific as 

 some of the other species of Cossidce. C. robiniw Peck and C. querciperda Fitch have 

 been known to extrude upwards of three hundred ova. In European species over 

 one thousand ova have been found on dissection. The rula of whole forests of tim- 

 ber in which these insects revel is doubtless prevented by the destruction of the eggs 

 by ants and birds, the size of the eggs being sufiBcient to form a tempting morsel. 

 In a state of nature the female Cossus deposits a small number of her ova upon each 

 tree which she visits until her supply is exhausted. 



This season the enlarged perforations through the bark show unmistakable evi- 

 dence that the trees had been recently visited by woodpeckers, which could find 

 little difficulty in procuring an abundance of full-grown larvae. 



C. centerensia is found throughout the region known as the pine barrens, which 

 cover an area of perhaps 12 square miles between Albany and Schenectady. The 

 soil of this region seems especially well adapted to the growth of the timber which 

 it supports. 



At the present time no correct observations have been made in reference to the 

 molts of the caterpillars, but information on this subject will soon be obtained from 

 Mr. A. H. Mundt, of Illinois, who has had opportunities of observing, up to the 

 fourth molt, the caterpillars of C. robiniw, which are found in the willows and pop- 

 lars in his vicinity. 



Cossus cenierensis appears every year, and from observations and from numerous 

 examinations of the trees by actual sections during the three months of the year 

 enumerated, I am convinced that the caterpillars are not fully matured until the 

 end of the third year, when they arrive at their perfect or winged state. The pupa 

 state is comparatively short, lasting less than a month before the moth appears. 

 From figures 3, 4, and 5 of Plate I we see representations of caterpillars found Octo- 

 ber 14, which establish the fact beyond dispute, through observations extending 

 over many years, that it requires three full years for the caterpillar to arrive at ma- 

 turity. 



8. Cossus ANGREZi Bailey. 



(Plate II, Fig. 6.) 



As this species will probably be found boring in the poplar, we re- 

 produce Dr. Bailey's account of it. 



We repeat the original description of this species, given in Papilio for June, 1882 

 (Vol. II, No. 6, p. 93) : 



" Cossus angrezi u. s. female. Head somewhat narrow on the vertex. Collar and 

 head yellowish gray, thorax black ; the edges of the tegulop shaded with yellowish 

 gray. Fore-wings with a nearly white ground, shaded with black, and with black 

 reticulations. Hind wings yellowish gray, mottled with blackish outwardly. The 

 fore-wings have the costal edge pale, marked with black ; the black shading obtains 

 on costa at apical third, and over the whole wing at terminal third, extending 

 obliquely downwards and inwards; there are a series of interspacial longitudinal 

 black streaks before the margin, more or less defined. Fringes whitish, dotted with 

 black opposite the ends of the veins, which latter conversely are whitish. Thorax 

 shaded with yellowish gray behind. Abdomen dark gray. Beneath the wings re- 

 peat the markings very distinctly, owing to the strong contrast of the pale ground 

 color with the black markings. Expanse, 82'"™. 1 female. Wells, Elko County, 

 Nev. From the late Mrs. Caroline Chase. Type, coll. James S. Bailey." 



