152 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
works only under cover of the lichens on the trunk and larger limbs, 
and apparently does not work on the twigs or younger branches as 
does the San Jose scale. While the European pear scale is not soserious 
a pest to fruit trees as is the San Jose scale, nevertheless its manner 
of working under lichens causes it to be neglected by fruit growers 
until the trees are badly infested, with consequent loss in vitality. 
SPRAYING EXPERIMENTS IN 1908: 
PLAN OF WORK AND MANNER OF APPLICATION. 
An orchard badly infested with the European pear scale (see PI. 
XIII) was selected in February, 1908, and divided into 16 plats of 
6 to 16 trees each. It was planned to examine a large number 
of scales in the laboratory from the treated trees of each plat, and-a 
like number from the unsprayed, or check, trees, and also to make 
field examinations as to the effect of the sprays on the scales, on the 
lichens, and on the trees. 
The applications of sprays were made February 18, 19, and 20 on 
plats 1 to 12; and March 3, on plats 13 to 16. A strong hand-pump 
tank outfit and also a barrel pump were used. No pressure gauge 
was on the pumps, but pressure was probably not more than 60 to 
75 pounds. Vermorel nozzles were used. 
SPRAYS USED AND METHOD OF PREPARATION. 
Plat 1, lime-sulphur wash.—This was made after the same formula 
described for the European fruit Lecanium. 
Plat 2, commercial lime-sulphur solution No. 1.—The stock solu- 
tion was used at the rate of 1 part to 9 parts of water. 
Plat 3, commercial lime-sulphur solution No. 2.—This spray, of 
different brand, was used at same strength as preceding. 
Plat 4, commercial 4 per cent distillate-oil emulsion.—This was used 
as follows: 
Distillate-oil emulsion). 2.2226 2 ees ee ee eee gallons.. 34 
Causticisdda ie M2 27: QoL Eee ee. eee ee ee pound... 
Water can bad axes dk eu ge cas tase ae eee gallons... 50 
Plat 5a, home-made 10 per cent distillate-oil emulsion.—This was 
made according to the following formula: 
Boiling waters oS: See a ee Sat ee ee gallons.. 5 
Fish-oil soap........- aT. Oe Se RS AS ee ee pounds.. 2 
Caustic soda niers ye Eee SRE A cee Ea donates 
Distillate (28° Bawmlé) srr eo eee ee ee ee eee gallons.. 5 
When the water started to boil, the caustic soda was added; then 
the soap, and finally the oil. The whole mixture was then forced 
through a pump to emulsify it; it was then poured into the barrel 
and necessary water (40 gallons) to make 50 gallons of the spray was 
added. 
