342 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 11 
40 per cent nicotine solution costing about $11.00 would be used to make 500 gallons 
of spray, 1 gallon of nicotine oleate costing about $6.50 would make 650 gallons of a 
spray solution as effective if not more effective than the spray containing free nico¬ 
tine. The nicotine oleate will cost the farmer about $1.00 a hundred gallons where 
the free nicotine spray will cost $2.20 per hundred gallons. 
To make the oil emulsion spray with nicotine oleate 10 parts of kerosene is mixed 
with 1| parts of commercial oleic acid and then 2§ parts of 40 per cent nicotine solu¬ 
tion is added and thoroughly shaken. Ten parts of water is then added and again 
thoroughly shaken. For use against mealy-bugs, white fly and soft scale this quan¬ 
tity is then mixed with 480 parts of soft water. 
In sprays where nicotine oleate is used the spray water must be soft (rain or dis¬ 
tilled water). To make nicotine oleate only those tobacco extracts containing free 
nicotine can be used. The stearate or palmitate of nicotine may be made in the 
same way, but is not as effective a spray as the oleate. Nicotine oleate is not volatile, 
hence should not be used on plants to be eaten, such as lettuce. The effect on plants 
has not been completely studied although sprays containing nicotine oleate equal to 
1 part of nicotine in 100 of water did not injure tomatoes or coleus. Slight injury 
was noted on tender leaves of greenhouse roses when sprayed at the above strength. 
On dormant trees the use of a rather nonvolatile oil such as linseed, cottonseed, or 
fish oil emulsified with nicotine oleate should be valuable .for the destruction of in¬ 
sect eggs or scale insects. 
A PATENT HAS BEEN APPLIED FOR THIS COMPOUND AND WHEN 
OBTAINED WILL BE GIVEN TO THE PUBLIC SO THAT ANYONE 
WILL BE ABLE TO MANUFACTURE IT. 
William Moore 
Notes From El Centro (California) Field Station. Not a trace of Hippo- 
damia convergens has been seen in or around Imperial Valley since the advent of mid¬ 
winter conditions, although the winter has been a very mild one thus far. Search in 
plant lice infested grain fields, basal volunteer shoots of cotton, along the banks of 
the Alamo and New Rivers, and at altitudes from 1,000 feet to 4,000 feet in the 
Laguna Mountains, west of the Valley, has failed to reveal any indications of hiber¬ 
nating ladybirds. 
An inspection of grain fields in scattered parts of the Imperial Valley, made Janu¬ 
ary 31, showed that all fields over a week old were quite generally infested with 
Aphis avence. The average infestation, as based on counts of 160 stools, was com¬ 
puted at that time to be 69.4 per cent. The colonies, which consisted of wingless 
females, their young, occasional nymphs, and rarely a winged migrant, appeared of 
rather recent establishment. Although parasites and syrphid larvae were seen, no 
Hippodamia individuals were present. 
The cotton aphis (Aphis gossypii ) is quite commonly seen on Malva leaves, to 
which related plants they have probably migrated upon the recent frosting of the 
cotton foliage. 
E. A. McGregor 
