10 
Florida Dispatch, November, 1885. Aleurodes pyrolce Gillette and 
Baker, was described in L895; Aleurodes herbericola Cockerell, in 
IS ( .H>; Aim ,-<></<* ruhnrum Cockerell, and Aleut-ode* uureocineta Cock- 
erell, in 1897. Since 1897 to date four species have been described 
from the United States, giving a total of thirteen, one an Aleurodicus 
and twelve belonging to Aleurodes. From the West Indies, Mexico, 
Centra] and South America twenty species have been recorded, seven 
of w hich are species of the genus d [I < u /-odious and thirteen of Aleu- 
rodes, Of these, six were described before 1895. It is evident, there- 
fore, to any one who has observed the variety of forms in this family 
that our knowledge of American Aleurodida3 is still very imperfect, 
and, with the exception of Aleurodes citri, our knowledge of their life 
history and habits is even more incomplete. 
The specific characters in the genus Aleurodes are derived mainly 
from the pupa-case, the adults, except in species with banded or 
spotted wings, offering but very little of use in characterization. In 
Aleurodicus, on the other hand, the most valuable specific characters 
are to be found in the adults, although to me there has appeared to be 
more variation in the pupa-case than has been generally stated. Ordi- 
narily, the founding of species on the characters derived from imma- 
ture stages of insects is unwarranted; but with this family, however, 
particularly in Aleurodes, as has been pointed out by Maskell and 
others, the pupa-case offers by far the more valuable characters, and it 
is doubtful if species could be satisfactorily separated, except in a 
few cases, from adult characters alone. Moreover, it is in the pupal 
stage that these insects are most frequently observed and collected, the 
minute "white-flies " that may be flying around being usually not asso- 
ciated with the stationary scale-like insects on the leaves. Again, 
injury is caused by these insects it is likely, mainly, in their immature 
stages, which fact, from an economic standpoint, renders it necessary 
that these stages be characterized. For these reasons the writer 
believes that the characterization of species of Aleurodes, at least, 
should be based largely on pupal characters; there is as much varia- 
tion, probably, in the pupa-case <>f differenl species of Aleurodes as 
there is in the species of Asjti.dtni Myt //<v.sy>/.v, Vhionttxpts, or other 
genera of the ( '<,<•<•!, ht. The w riter by no means favors the disregard 
of the imagoes, and especial effort should be made by collectors to 
Secure this Stage. 'Phis ordinarily may be easily done, where the 
pupie are somewhat numerous, by placing the leaves in a jar for a few 
day-, to allow the more mature pupa 4 to develop into adults. 
To preserve Aleurodida 1 satisfactorily for study it is advisable to 
keep two series. As soon as material is collected, specimens of all 
stages should be mounted in xylol balsam on slides, after careful 
live notes" have been taken, particularly with reference to the col- 
oration of the differenl parts, and with adults as to the division or not 
