30 THE FLORIDA BUGGIST 
THE EFFECTS OF THE FREEZE OF FEBRUARY 2-4, 1917 
ON 
THE INSECT PESTS AND MITES ON CITRUS.* 
By W. W. YOTHERS, Bureau of Entomology, 
Orlando, Florida 
WEATHER CONDITIONS AND TEMPERATURES 
For more than five weeks prior to February 1st, the weather 
had been very warm. Many days the temperature reached 85° 
F., at Orlando, Florida, and on February 1st it reached 86° F., 
and it was a very sultry, calm day. Between 6 and 8 o’clock p. m., 
about half an inch of rain fell and there was more or less rain 
the entire night. The rain was followed immediately by a heavy 
wind from the northwest, which continued until late Saturday 
afternoon. It was quite calm, however, Saturday night. 
The following minimum temperatures of localities, where ex- 
aminations were made to determine the conditions of pests, were 
taken from the U. S. Weather Bureau: 
Putnam-County, Crescent:Gity 22) = 19°F. 
Volusia «County; - Deland 22 ee gS the 
Marion .County,. Ocala) 22.22 18°F. 
Lake: Countys-MiUStis <2. 222 ete ee Z0CK: 
Orance County. Orlando: 23.2 PAPA tie 
Polk County, Winter’ Haven: ....-4) 22s PAB he 
Polk County, rostprool. = ee PATE Oe 
Pinellas: County; PinellassParkos eee Zoe 
The zone of the lowest temperatures, from 15° to 
20° F., comprise the citrus producing counties of Putnam, Vo- 
lusia and Marion, with parts of Lake and Orange. In this zone 
there was practically complete defoliation of all citrus trees. 
Many grapefruit trees were killed to the ground and the oranges 
were killed back to within, from 4 to 8 feet of the ground. Hare 
in his report on the effects of the freeze+ gives the following es- 
timates of the percentage of the bearing wood that had been kill- 
ed: Oranges Grapefruit 
Pubmani* Coun tye. ee ee 80% 90% 
Molusia: Countyess eee 90% 95% 
Marion © OUI yeas 08 ne eee 15% 85% 
Rartotslake:Countys2 =e 30% 40% 
Part.or Orange County = = 40% 50% 
*Published by permission of the Chief of the Bureau. Read before the Florida Entomologi- 
cal Society October 10, 1917. 
+Hare, C. C., “Report on Effects of the Freeze.’ U. S. Bureau of Crop Estimates. 
