324 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



removed to clean water in which the body contents are washed out 

 with more than usual care. They may then be transferred directh' to 

 the stain, which for this purpose is most conveniently contained in 

 deep-hollow slides having a ground glass surface upon which data may 

 be written, covered with a cover glass and set away. Six hours in the 

 stain is sufficient, this being in strong contrast to the 100 hours recom- 

 mended by Stafford. The specimens are removed from the stain into 

 95 per cent alcohol in which the excess stain is washed out, are then 

 placed for an instant in carbol-xylene and mounted in balsam. 



The result is a preparation in which all chitinized portions, the 

 antennae, legs, setse and chitinized areas, are stained a more or less 

 deep red while the remainder of the derm is left practically unstained. 

 It not only becomes easier to study the characters that can be seen in 

 the usual mounts but other characters are brought out that are not 

 ordinarily to be seen and that have not, as far as I am aware, pre- 

 viously been noted by any one. 



Smith^ has pointed out the possible value as specific criteria of the 

 "cerrari" or groups of pores and differentiated spines that occur on 

 the margin of the body and these structures are indeed of much impor- 

 tance. In fact it is probable that a much more satisfactory basis for 

 generic groupings can be found in the number of pairs of these cerrari 

 than in the characters at present used and they are also of value for 

 the recognition of species. 



■ In addition to these cerrari, however, there occur in some species, 

 certain chitinized and deeply staining areas associated especially with 

 the cerrari of the anal lobes and on the ventral side of these lobes. It 

 is these areas of which I have previously spoken as characters not 

 previously noted. They are remarkably constant in shape and extent 

 and permit the' instant and certain recognition of some species. In 

 other species they are not present, in which case the cerrari alone 

 must be relied upon. With the use of all these characters, the cerrari, 

 the dorsal and ventral body setjB and the chitinized areas, the dis- 

 tinguishing of the various species of mealy-bugs becomes in general 

 practically no more difficult than the distinguishing of the various 

 species of diaspine scales. The differences are readily appreciable and 

 are no more variable than those which must be used in almost any 

 group. Given proper study upon the basis of adequate material and 

 with the aid of the methods here advocated, or of equivalent methods, 

 the present confusion in the "soft scales" should rapidly disappear. 



1 Smith, P. E. A Study of Some Specific Characters of the Genus Pseudococcus. 

 Journal of Entomology and Zoology, vol. 5, pp. 69, 81, figs. (1913.) 



