252 ENTOMOLOGICAL NEWS. [October, 



If this is done the larva renews it promptly. So long as this white scale 

 remains the larva does not moult, and larvae only have been found under 

 it. The black scale is formed by waxy excretions from the insects, ap- 

 pearing in narrow wings at the edges of the white scale, which is gradu- 

 ally lifted and forms a central covering which, in a short time, either 

 shrivels and falls off, leaving a discernible torn edge, or it actually 

 changes colors. In other words, the white scale and the black scale are 

 produced in the same way and consist entirely of wax or waxy excre- 

 tions. No exuvium is ever found under such a scale and none ever forms 

 part of it. On close examination under the microscope it is shown that 

 the insect is really in the larval stage as yet, though the legs and other 

 appendages have lost function. The chitinous walls of these append- 

 ages are yet present ; but the contents have been completely absorbed. 



Moulting is coincident with the beginning of the final scale, which is a 

 totally new structure of which the exuviae or cast skins form a part. 



I have myself noted the fact that the insects that live through the 

 winter and start reproduction in spring are those under the black scales 

 or, as I described them, half-grown scales. I do not believe, and so 

 stated, that any specimen that becomes sexually mature and begins to 

 reproduce in fall ever resumes breeding in spring. The fact that repro- 

 duction begins so generally at one time — in New Jersey, June 10 — argues 

 that the insects that survive are all in about the same stage, which Dr. 

 Reh's observations indicate is as the larva. This affords a reasonable 

 explanation, not only for the late date that reproduction begins, but for 

 the fact that within less than a week almost every surviving individual 

 seems to be bringing forth young. 



The final scale begins as a paler ring at the margin of the black scale, 

 and the latter, for a time, forms the nipple or covering. This in time 

 meets the fate of the white scale, is cast or rubbed off and leaves the 

 yellowish centre. 



A curious fact seems to be that whereas in American examples the 

 complete black covering to the adult scales is exceptional, in the Japan- 

 ese examples it seems to be the rule. Dr. Reh thinks that Cockerell's 

 species andronielas and albopunctatus are based upon examples of perni- 

 ciosus varying in the presence or absence of this second black scale. 

 Dr. Reh also inclines to agree with European authors concerning the 

 method of moulting, and considers Howard and Marlatt in error in de- 

 scribing the separation of the old larval skin into a dorsal and ventral 

 half. He believes, on the contrary, that the skin splits transversely be- 

 fore the mouth parts and that the insects wriggles out through the slit so 

 formed. 



The entire paper is suggestive and well repays careful reading though, 

 as already stated, the breeding notes should not be too literally applied 

 to field conditions in America. 



