28 WHITE FLIES INJURIOUS TO CITRUS IN FLORIDA. 
above, with A. citri, and failing to find any differences in the egg and 
pupal stages found it necessary to regard the name given by Maskell 
as a synonym of that given by Riley and Howard. 
The citrus white fly does not occur in Cuba, so far as known, 
although it is not unlikely to be found there, since there have been 
heavy shipments of nursery stock from infested citrus nurseries in 
Florida to that country during the last few years. 
FOOD PLANTS. 
AUTHENTIC AND QUESTIONABLE RECORDS. 
The separation as distinct species of two forms formerly considered 
as belonging to the species Aleyrodes citri makes it necessary that 
all of the reported food plants of the citrus white fly be verified. 
Nearly 60 species of the genus Aleyrodes have been recorded for 
North America. Of these less than 20 have been described in the 
first larval stage in a manner which distinguishes them, although 
when carefully studied this stage has been found to have striking 
specific characters. The second and third larval stages rarely possess 
distinguishing characters. The fourth or pupal stage, or the empty 
pupa case, is used as the basis of specific descriptions in the Aley- 
rodidae, but even in this stage a careful microscopic examination is 
usually necessary to positively determine the species. Good specific 
distinctions in the adult stage have been found only in a few species, 
and even those entomologists who have made a specialty of the Aley- 
rodidae do not attempt to distinguish the different species in this 
stage. It is obvious, therefore, that a list of food plants should 
properly include only those verified by entomologists, with determin- 
ations of the species made since the status of the two most abundant 
citrus-infesting species of Aleyrodes has been fully recognized. Dr. 
E. W. Berger has recently arranged the full list of food plants and 
reported food plants in a graphic manner, separating the list into 
two classes according to the degree of preference, and each class is 
subdivided into native and introduced species. This method of 
grouping the food plants is here adopted (see Table IV) with the 
transposition of the lilac and coffee from class II to class I and omit- 
ting certain reported food plants in order to restrict the list to include 
only positive records, leaving the others for a separate discussion. 
Dr. Berger has recently discovered the citrus white fly on wild olive, 
and has also verified Prof. Gossard's report of the citrus white fly on 
Viburnum nudum. Both of these food plants, together with the 
green ash, probably will eventually be found to be subject to heavy 
infestation and be placed in class I. 
