INSECTS AFFECTING PARK AND WOODLAND TREES 477 



The female, in its appearance, approaches nearer C. quercipcrda 

 Fitch than any other of our species. The collar and thorax are black, 

 edged with gray scales. The abdomen is black above, interspersed with 

 gray scales towards its tip, and more thickly beneath. The primaries are 

 black over rather more than their inner half, with some gray scales a little 

 within the center of the wing; the center portion of the wing beyond the 

 reniform mark is grayish. The wing is traversed by broken, black, transverse 

 lines, of which twenty or more can be counted on the costal margin ; three 

 or four of those on the outer portion are more continuous and conspicuous 

 than the others. The fringe is marked with black scales opposite the veins. 

 The secondaries are nearly transparent, darker along their inner margin, 

 showing some faint reticulations, which are more conspicuous beneath. 

 [The type is illustrated on plate 44, figure i.] 



The male strongly resembles the female, instead of presenting the 

 marked contrasting differences found in Prionoxystus robin lae 

 Peck and P. macmurtrei Guer.-Men. Its wings are only a little more 

 projected apically than in the other sex. 



Expanse of wings of the pair in my collection, male 2 inches; female 

 2.5 inches. Length of body, female .95 inch; male 1.2 inch. 



Life history. This species has been carefully studied by Dr Bailey, and 

 the following account of its life history is based largely on his published 

 observations. The recently emerged moths are rather sluggish and can be 

 easily captured. They resemble the color of the bark so closely that it 

 requires a very good eye and close observation to find them. After the 

 moths have been abroad a few days, they are wild and more or less muti- 

 lated. The females deposit their eggs in clefts near the base of the trunk, 

 one producing over fifty. This species appears every season, and observa- 

 tions seem to indicate that three years are necessary to complete the life 

 cycle. The pupae, as in the case with related species, wriggle partly out of 

 the burrows before disclosing the moths, and these conspicuous empty 

 pupal cases are therefore a very convenient means of detecting the number 

 of moths which should be found about infested trees. 



Remedial measures. It is probable that this species could be con- 

 trolled in the same way as the carpenter w-orm noticed on pages 79-84. 

 Ordinarily the poplar is of so little value and this insect so rare, that it will 



be unnecessary to check it. 



Bibliography 

 1890 Packard, A. S. U. S. Ent. Com. 5th Rei)'t, p. 439-42 



