666 
Journal of Agricultural Research 
Vol. XXI, No. 9 
SUMMARY OF BIOLOGY 
Following are the important points in the biological study in relation 
to control: 
1. The most important means of distribution is through imported 
palms and offshoots from infested trees. These offshoots are invariably 
severely infested and carry the infestation through propagation to new 
plantings. 
2. The main infestation on a mature palm is limited to the area ex¬ 
tending iX to 3 feet below the crown, the crown tissues being free of 
scales. Lighter infestations continue on down the bole even to the 
ground. 
3. From July to April practically all of the scales are concealed be¬ 
neath the leaf and fiber bases and on the fruit stems of the current year. 
4. The so-called spring migratory period of the scale is from April to 
June, and it is at this period that the new tissues and fruit stems become 
infested from the infested area of last year’s fruit stems. 
5. The majority of the exposed generations of the migratory periods 
out on the leaves are killed by the dry, hot weather following the migra¬ 
tion, though some may persist in certain protected pinnae and reproduce 
a limited number of scales. 
6. The scale is found in all stages of development at all seasons of the 
year on the soft tissues of the leaf base and fiber band tissues. This 
indicates a continuous overlapping of generations. The duration of each 
generation is apparently from six to nine months. 
CONTROL METHODS 
Though the exposed red date-palm scale is readily killed by most con¬ 
tact insecticides its protected position under the leaf bases and tight 
fiber bands makes control by spray or fumigant most difficult. It is 
necessary to use a spray which will penetrate deeply between the fiber 
bands and leaf bases and to repeat the applications consistently in order 
to reach the maximum number of scales. As shown in the biological 
studies, it is important to check the migrations of the scale, thus pre¬ 
venting the new tissues and fruit stems from becoming infested. 
The formula and spray calendar recommended by Mr. Drummond and 
Mr. Shamblin are as follows: 
Liquor cresolis compositus, U. S. P.j part 
Distillate or kerosene.. parts. 
^ a ^ er .•.50 parts. 
If kerosene is used in making the stock solution, only the very best grade should be 
used, as oils of low specific gravity tend to retard good emulsion, in many cases injuring 
the offshoot or growing palm. 
The spray is best applied by a power sprayer with a good agitator and 
under 200 to 225 pounds pressure, two leads of 30-foot spray hose being 
used. Six-foot to 12-foot spray rods with driving-spray nozzles set at 
