— 3— 

 stated, without his assistance the preparation of the present 

 paper would have been impossible. His kindness in corres- 

 ponding, suggesting, and in loaning type specimens from his 

 private collection, cannot be too highly spoken of. 



It may also be permissable to say that the writer intends 

 to continue the study of this interesting group, and that criti- 

 cisms and suggestions will be gladly received from all. 

 Specimens sent for identification will be promptly examined 

 and returned except where such specimens are evidently new 

 or rare, when a portion of the material will be retained and 

 the remainder forwarded after being studied. 



Genus- aspidiotus Bouche. 



Diaspinae with female scale round or nearly so, with 

 exuviae at or near the center. Male scales slightly elon- 

 gated. Last segment of female having generally four groups 

 of ventral glands, though these are sometimes five in number 

 or wanting. 



A. Species in wliicli tiie anal segment of the female possesses two 

 median lobes well developed; second and third lobes only par- 

 tially developed or rudimentary. 

 B. Female anal segment with incisions having markedly thickened 

 edges; plates small or spine-like. Most species with scale 

 small or dark colored. Occurring on deciduous trees in the 



northern part of the temperate zone Subg. Diaspidiotus. 



BB. Female anal segment with marked incisions but with chitinous 

 processes thin, or replaced by a broad chitinous band; seg- 

 ment usually with a dense fringe of plates, these often multi- 

 branched. Occurring for the most part in the lower austral 

 and tropical zones Subg. HemiherUsia. 



Subgenus diaspidiotus (Berl. and Leon.) Ckll. 



A. Female anal segment with plates short and simple, or absent, not 

 forming a marked fringe. 



*A summary of the principal subgenera or the genus is given in a bnlletin by 

 Prof. Cockerell, Tech. Ser. No. 6, Div. Ent. U. S. Dept. Agr. 



