87 
Results of applications of insecticides made in Curtis Park, Denver, for the cot- 
tony map’e scale. 
[Treated November 238, 1903; examined February 27, 1904. ] 
mo. e8 Insecticide. Strength. Alive. | Dead. Percent Remarks. 
2 Kerosene emulsion.___} 50 per cent oil _______| None. | - All. 100 
Sill eee Gost as ere eee 20 per cent oil __-----| None INU 100 
Ab Noe ee dose ee 12# per cent oil __--.- He 98 
Syl es lea LON mcrae ala taal 10iperlicentoleses22 85 213 88 
6) |} Robaccorstems|22.25222 1 pound to 1 gallon _- 217 89 29 
(lod teens COs ee pounditosreallonsys |e ss2s nee are |e ae A No benefit. 
TG Nietevenisto) 0) eee eee eee ZA POUNGSktom ee allo mys | eee se | epee he eee Seales all dead 
and shriveled. 
1G Sas. COs ere lkpoundstoei gallons) |e see see eee ae 60; About two- 
thirds dead. 
(UAE YON sc eres eee, Dans Hel APS Sa SU ga a sc ke ae a eet S| 25 | One-fourth dead. 
Results of later applications in Curtis Park. 
[Treated February 19, 1904; examined March 1, 1904.1] 
Insecticide. Strength. Alive. | Dead. Pep cent Remarks. 
Lime-sulphur-salt (Illinois for | Full ____...-....-_-.-- 87 192 70 
mula). 
Kerosene emulsion __....-.--..---- pOperwicent sess Lee 0 404 100 
EID) eS ee TN = al fa aul eh CMe BO DeCRICe Tt ee ae 0 310 100 
ATE) Gye ae NE EDs yl Ties ape Aas aia ADIpeTICent eee aan 5 274 98 
EL) Spy eT ee Se le pe Cente sees ft 153 99 
TB Yc Ys Stoo ot a aren arty St Sc IZpericent a =a asanen! 14 229 94 
1B) @ ape ee Pay oO crt OE Paves A LO percent 555422 2-— 299 688 69 
Whale-oil soap (hard)-____....----- 1 pound to 1 gallon -- 3 171 98 
1D YO Ses cee ee ee ne ae Re es 1 pound to 2 gallons - Manes 563 84 
1D Yo) aS SoS apa eau a DS Te pene er 1 pound to 8 gallons - 26 81 76 
TB) Ee Ss sre ene er ge ay eae i ee 1 pound to 4 gallons - 128 154 55 
DD) Oa es pe eae eee oer 1 pound to 8 gallons - 118 154 7 s 
OEE FES a la 2 oem ee ei | GR NAD ta ea 256 421 62 
PREPARATION OF INSECTICIDES. 
The kerosene emulsion was emulsified with whale-oil soap. The 
tobacco stems were very dry when weighed and were boiled one hour 
in enough water to cover them, after which the concoction was 
diluted to the strengths given. The tree soap employed was used in 
the first series of experiments and hard whale-oil soap, purchased at 
a drug store, in the second. The lime-sulphur-salt wash was _ pre- 
pared according to the Uhinois formula and boiled three hours. 
APPLICATION OF THE INSECTICIDES. 
Both seneca and vermorel nozzles were used. The latter did 
good work and is rather to be preferred on account of economy of 
material. _Only the lower branches of the trees were sprayed and in 
some cases two applications were made on different parts of the same 
tree. With the lime-sulphur-salt wash two entire trees were treated. 
