CITRUS EXPERIMENT STATION
LAKE ALFRED, FLORIDA CES Mimeo Series 70-6

S" 4 CITRUS INSECT AND DISEASE SUMMARY
END OF AUGUST 1969

Statewide Index of Abundance
I I 1 I I I
Mid-Aug. End Aug. Trend Mid-Aug. End Aug. Trend
-2.0


S Rust mite

1.5 ~ Black scale
High for
mites D-


1.0 High for ___
scales;
whitefly Whitefly
Smealybug "-
C. red mite-->
0.5 o ---> Glover s

-. Mealybug

Texas C. mite

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

Rust Mite: 69% of groves infested (Norm 50%); 54% economic (Norm 33%).
Population is still in the high range and much above normal despite the August decrease.
Fruit will be more heavily infested than foliage. Little change is predicted until late
September when an increase is expected. Highest districts are South (2.05) West (2.00)
Central (1.50) and North (1.07).
Texas Citrus Mite: 22% of groves infested (Norm 23%); 7% economic (Norm 9%).
This mite is at the normal low level for this date and will continue to decrease.
Gradual increase is expected in October. Highest district is East (.57).
Citrus Red Mite: 30% of groves infested (Norm 28%); 14% economic (Norm 12%).
Population is near normal and low. Further decrease is expected through September,
followed by gradual increase in October. Highest district is North (.62).
Glover Scale: 43% of groves infested (Norm 44%); 10% economic (Norm 8%).
Population decreased and is currently at the normal low level. Little change is
expected. Highest districts are North (.76) and West (.75).
Purple Scale: 27% of groves infested (Norm 44%); 2% economic (Norm 2%).
This scale is below normal and will remain at very low level. Highest district is
North (.52).
Chaff Scale: 37% of groves infested (Norm 34%); 4% economic (Norm 3%).
Population is normal and low with little change expected. Highest district is
North (.62).
Yellow Scale: 46% of groves infested (Norm 43%); 8% economic (Norm 7%).
Population is near normal and low except in North district which is in the high range
(1.05). Slight increase is expected.
Black Scale: 64% of groves infested (Norm 57%); 44% economic (Norm 36%).
Population is decreasing but probably will remain in the high range through mid-
September. The late summer brood of crawlers is evident on leaves. Most of these will
die and the survivors will not be a threat until next year. Highest districts are Cen-
tral (2.05) and South (1.14).
Snow Scale: 20% of groves infested; 9% with moderate to heavy infestations. Population
increased and is greater than in prior months. Further increase is expected.
Whitefly: Adults are present in 87% of groves and abundant eggs are being deposited on
new flush. The larval form is currently at normal moderate level but is expected to
increase in October.
Mealybug has decreased to the low level normal for the end of August.
Note: The next Summary will be issued about mid-October. Most citrus pests except rust
mite will be at low ebb until then. However, watch for buildup of rust mite, Texas citrus
mite and citrus red mite. Control mites before more than 15% of fruit or leaves are
infested. Watch for brown rot in susceptible groves.


600 September 4, 1969 WAS


W. A. Simanton