16 THE CANADIAN ENTOMOLOGIST. 



and again, A. fusca is decidedly numerous on peach twigs. Lastly, the 

 second female pellicle is larger than the adult insect. 



Judging, therefore, by all the external characters (except that of the 

 second pellicle, of which I find no record), Aonidia fusca is different 

 from AsPiDiOTUs perniciosus. 



But a careful comparison of the adult female insects shows that, with 

 the exception of size, their characters are very similar. My specimens of 

 Asp. perniciosus (originally received from Professor Comstock) average 

 one 25th inch in length ; those of Aon. fusca average one 65th inch. 



In colour the two agree ; also in the absence of any groups of 

 " spinnerets " ; also in the terminal lobes, hairs, and indentations of the 

 abdomen. The two last characters are of especial importance ; so much 

 so that I am strongly inclined to think that I made a mistake in separating 

 the two insects, at least specifically. The identity of my Australian 

 specimens of Aspid. perniciosus with those from America is absolute ; 

 my Australian Aonidia is anatomically very close to both, the principal 

 differences being external. 



It remains to discuss the generic character of the comparative 

 dimensions of the adult female and the second pellicle, a character which 

 distinguishes Aonidia from Aspidiotus. I have already remarked that I 

 find no notice on this point in any author as to A. perniciosus ; but as 

 regards A. fusca I have no doubt, and I possess a mounted specimen of 

 an adult with the second pellicle still attached, the difference in size being 

 perfectly clear ; the pellicle extends all round beyond the adult. Assum- 

 ing, therefore, that it may be necessary to unite the two insects, and to 

 make fusca a variety of perniciosus on the ground of anatomical 

 similarity, ignoring the external differences, it will become a question, 

 then, of removing perniciosus from the genus Aspidiotus and of 

 attaching it to the genus Aonidia. 



It is stated in " Insect Life," Vol. VI., p. 362, that while the origin 

 of A. perniciosus is uncertain, the probability is that it came to America 

 from Japan. I believe that Mr. Koebele is in Japan at present studying 

 the Coccidse of that country ; and he has, perhaps, discovered the native 

 home of this injurious pest. But, in a letter which I received from him a 

 few months ago, he says that the Japanese will not permit any specimens 

 of insects to be sent thence by post ; and we must wait till Mr. Koebele 

 himself leaves the country to learn more about this scale. Mr. Benson, 

 of Sydney, however, tells me there have been many fruit trees imported 

 into Australia of late years from Japan, 



