0

34 -


CITRUS EXPERIMENT STATION
LAKE ALFRED, FLORIDA


CES Mimeo Series 69-9


CITRUS INSECT AND DISEASE SUMMARY
END OF AUGUST 1968


Statewide Index of Abundance


Trend


\ V Rust mite
on fruit

\ \


lvs.\\


C. red mite


Texas C mite

Texas C. mite">


High for


mites

\, High for


Mid Aug. End Aug. Trend



\Black scale

\

\


scales
Ix,^

* !--. >Whitefly
>Mealybug
-> Glover sc


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

Rust Mite: 52% of groves infested (Norm 50%); 41% economic (Norm 31%).
Population dropped out of the high range for the first time since September of 1967.
Further decrease to the normal low level for September is expected. Infestations are
heavier on fruit than on leaves. About 20% of groves in all districts will harbor
heavy infestations. Highest districts are West (1.67) Central (1.29) and South (1.10).
East district has a high population on fruit (1.54) but not on leaves.

Texas Citrus Mite: 23% of groves infested (Norm 23%); 7% economic (Norm 9%).
Population is below normal and in the very low range. Further decrease is expected.
Highest district is West (.60).

Citrus Red Mite: 32% of groves infested (Norm 27%); 7% economic (Norm 13%).
Population is near the normal low level for this time of year. Some further de-
crease is expected. A few scattered groves will develop moderate to heavy infestations.
Highest district is West (.80).


Glover Scale:
Purple Scale:
Chaff Scale:
Yellow Scale:
Snow Scale:


43%
32%
19%
27%
14%


groves
groves
groves
groves
groves


infested (Norm 44%); less than 1% economic (Norm 10%).
infested (Norm 46%); less than 1% economic (Norm 2%).
infested (Norm 37%); less than 1% economic (Norm 4%).
infested (Norm 48%); less than 1% economic (Norm 8%).
infested; 1% economic (No norms established).


With the exception of snow scale, the armored scales listed above are all below
normal abundance and in the moderate or low range in all districts. Slight decrease is
expected. Snow scale is expected to increase.

Mealybug: 57% of groves infested; 8% economic. Population is above normal for this
time of year but infestations are mostly light and are decreasing.

Whitefly: 38% of groves infested; 18% economic. Population is near normal and in the
low range. Adults will become more numerous but will not be of much importance at
this time.

Note: Rust mite is the only pest likely to require control in September. To avoid
russetting, do not allow it to infest more than 20% of leaves or fruit.


THE NEXT SUMMARY WILL BE ISSUED IN EARLY OCTOBER


625 September 3, 1968 WAS


Mid Aug.
v\
1


End Aug.


-2.0


-1.5




-1.0




-0.5


L 'mr Y


W. A. Simanton