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CITRUS EXPERIMENT STATION
LAKE ALFRED, FLORIDA


CES Mimeo Series 69-26


CITRUS INSECT AND DISEASE SUMMARY
END OF MARCH 1969


NOTE: Only pests or conditions of general or current interest are reported.
Forecasts are for 1 month in advance unless otherwise indicated.

Rust Mite: 65% of groves infested (Norm 60%); 50% economic (Norm 41%).
Population decreased but is still in the high range and above normal for this date.
Further decrease is expected through April. Highest districts are South (1.88) West (1.86)
and North (1.79).
Texas Citrus Mite: 33% of groves infested (Norm 36%); 14% economic (Norm 16%).
Population is in the low range and slightly below normal. Increase is expected in
late April. Highest district is Central (.66).
Citrus Red Mite: 29% of groves infested (Norm 43%); 9% economic (Norm 17%).
This mite decreased and is expected to remain below normal and in the low range.
Highest district is East (.59).
Six-spotted Mite: 6% of groves infested; less than 1% economic.
Population is below normal and in the low range. Gradual increase is expected through
May.


Glover Scale: 68% of groves infested (Norm 79%); 6% economic (Norm 19%).
Purple Scale: 63% of groves infested (Norm 79%); 7% economic (Norm 10%).
Yellow Scale: 80% of groves infested (Norm 65%); 4% economic (Norm 12%).
Black Scale: 17% of groves infested (Norm 29%); 5% economic (Norm 11%).


Chaff Scale:


36% of groves infested (Norm 65%); less than 1% economic (Norm 12%).


All of the above scales continue to be at low to moderate level in all districts.
Activity has been below normal this spring and little increase is expected before May.
Snow Scale: 16% of groves infested; 7% moderate or heavy. Population is above normal
for March and will increase.
Whiteflies: 58% of groves infested; 12% economic. Population of the larval stage is
slightly above normal but is still in the moderate range. Adults will become numerous.
Mealybug population is below normal and at very low level. Little increase is expected
before May.
Aphids: 22% of groves infested; 2% economic. Population is near normal and currently
in the low range although it is increasing rapidly. Further increase will occur until
May, but the statewide spring infestation is expected to be below average.
Spray Notes: The bloom period is a few days earlier than last year but is about 3 weeks
later than average. The second spray for scab control should be applied when 2/3 of the
petals have fallen.
Dr. R. F. Brooks recently reported that trithion 4 liquid and ethion 4 liquid are
effective against snow scale when used at 3.75 pints per 500 gal. Thorough coverage of
wood is essential with any scalicide intended for snow scale control.


625 April 3, 1969 WAS


W. A. Simanton