THE CITRUS WHITE FLY: SEASONAL HISTORY. 85 
southern portions. Prof. H. A. Gossard has stated that at Lake 
City in 1902 white flies began to appear no earlier than April 14, and 
continued to appear until late in May, although the majority of them 
emerged during the latter half of April, while in 1903 the same trees 
produced adults as early as March 12, or but one week later than 
groves at Orlando and Palmetto. While the spring brood of adults 
at Orlando in 1909 had begun to emerge as early as February 20 and 
had reached their height and begun to decline by March 27, on the 
latter date in St. Augustine only 5 per cent of the pupz had devel- 
oped the eyes of the adult and practically no adults had emerged. 
Professor Gossard also is authority for the statement that at “Tampa, 
30 to 40 miles north of the Manatee section, the spring brood of 
white flies has in some seasons preceded their appearance about 
Bradentown and Manatee by two weeks.” By June 18, 1909, more 
than twice as many adults of the second brood had emerged at 
Manatee as at Island Grove about 125 miles north in Alachua County, 
while by July 7 of the same year the white fly in a grove at Alva in 
Lee County was no further advanced than at Orlando. 
From the curve in figure 12 it will be noticed that there are two 
periods of about three weeks during the summer between the broods 
when adults are comparatively very scarce. While reference to 
Table XVII shows that a few wintering-over individuals continue 
to emerge as late as early May, the period between the first and sec- 
ond broods of adults is exceptionally free from adults of the citrus 
white fly. This, however, is not true of the like period between the 
second and third broods as before this time the generations of the 
white fly have become somewhat confused, due to variation in life 
cycle, and adults continue to emerge in appreciable numbers through- 
out the period. 
In speaking of the entire citrus belt, including Florida and the 
Gulf States, the greater part of the spring brood may be said to 
emerge during March and April; the second brood to emerge during 
late May, June, and July, and the third brood during August and 
September. It should be noted here that the greater part of the 
adult white flies appearing in October and November in the central 
and southern part of Florida are the cloudy-winged white fly, A. 
nubifera, although in the northern part adult specimens of A. citra 
have been seen in small numbers on the wing in St. Augustine as 
late as November 15. 
