Florida Agricultural Experiment Stations


 Use of Parathion on Citrus in Florida
 Parathion is used primarily for the control of scale insects
 but it may be used as an aphicide and it may be used also in
 the control of such insects as grasshoppers and pumpkin bugs.
 However, most parathion is used as a replacement for oil sprays
 in the control of purple scale and Florida red scale. Two basic
 recommendations have been made for parathion applications. If
 a single parathion application is to control scales for an entire
 12-month period, it is recommended that 1%/ to 2 pounds of
 a 15 percent wettable material be used per 100 gallons of spray,
 and that this spray be applied during June, July or August.
 If it is desired to split the parathion application into two
 parts, one should be applied at post-bloom time and the second
 during the period from June through August. Each spray
 should contain only 1 pound of a 15 percent wettable material
 per 100 gallons of spray. Both spray programs were followed
 during 1950 and gave results generally as satisfactory as oil
 spraying.

 Precautions for Handling Parathion
 The precautions suggested below are designed to minimize
 the hazards which may exist during parathion spray operations
 or after a grove has been sprayed. All are designed to reduce
 possible parathion exposure and all should be rigidly adhered
 to. Brief exposures to parathion are not particularly hazardous,
 but the more prolonged the exposure the more dangerous it is.
 Where men are to be exposed to parathion sprays for more than
-a week medical examinations should be given prior to employ-
ment (7, 25). This examination should include a general physical
check-up as well as specific tests for liver function (serum
protein), blood cholinesterase and anemia. A history of liver
disease, low serum protein, low blood cholinesterase or anemia
could predispose an individual to parathion poisoning. Psycho-
logical instability could easily result in cases of simulated para-
thion poisoning.
 It is important that red blood cell cholinesterase be deter-
mined for all individuals who are to spray with parathion. This
test would serve several purposes. It would indicate whether
normal levels of red blood cell cholinesterase are present before
the man starts using it. His own norm would thus be established
and cholinesterase tests at a later date would be more readily