THE CLOUDY- WINGED WHITE ELY: INJURY. 87 
The white fly known as the cloudy- winged white fly was first 
determined as specifically distinct from the citrus white fly by Dr. 
E. W. Berger in 1908. Dr. Berger has recently given this species 
its scientific name in connection with a synopsis of the principal 
distinctive characters and illustrations of egg and larval and pupal 
stages. 1 
AMOUNT OF INJURY BY THE CLOUDY-WINGED WHITE FLY. 
The injury caused by the cloudy-winged white fly is at present 
much restricted by several factors. In Florida the distribution of 
this species is limited as compared with that of the citrus white fly. 
Its food-plant differences and adaptations are such that orange 
trees 2 are not as a rule subject to as heavy infestations as by the 
citrus white fly, although with grapefruit trees this situation is 
usually reversed. Most important as a factor limiting the injury 
from the cloudy winged white fly is that when both occur in an 
orange grove the citrus white fly almost invariably predominates 
and the cloudy-winged white fly assumes a position of comparative 
insignificance. Owing to the difference in the seasonal history of 
the two species of white fly this latter point is not always apparent 
to the casual observer. An observation made between the broods 
of adults of the citrus white fly, or at any time after the middle of 
September up to December 1, may result in noting a great pre- 
ponderance of the cloudy-winged white fly, leading one to conclude, 
perhaps, that it is this latter species which is causing the most injury. 
An examination of the leaves during the winter months, when there 
are practically no adults of either species, will probably show an 
entirely different situation. In many groves near Orlando and 
Winter Park in Orange County, Fla., both species of white fly are 
well established and practically have assumed their normal rela- 
tive positions in point of numbers. Examinations of leaves varying 
in number from 85 to 400 picked at random in 11 of such groves 
furnish data which illustrate the general situation as regards the 
importance of the two species of white fly under the conditions 
mentioned. (See Table XVIII.) All the examinations were made 
during the winter months, using pupa cases and live pupae as the 
basis of the comparison. 
1 Bulletin 97, Florida Agricultural Experiment Station, pp. 68-70, figs. 12, 14, 16, 
18, 19. 
2 According to the latest statistics available (Ninth Biennial Report of Commis- 
sioner of Agriculture, State of Florida) there were more than five times as many orange 
trees as grapefruit in Florida, 1,786,944 orange trees being reported for 1905 as against 
373,008 grapefruit trees. 
