- 4- 
Insecticidal Materials 
The most satisfactory insecticides for use against the Xuropean 
corn borer are made with derris, cube (pronounced koobay), or nicotine. 
Owing to shortage of derris and cube resulting from war conditions, 
the use of these insecticides is temporarily restricted by law to 
certain food crops vital to the war program. Restrictions of use 
have not been applied to nicotine insecticides. Nicotine, when com- 
bined with chemical materials which prevent its loss by evaporation, 
is a very useful corn borer insecticide. One of these mixtures, 
nicotine bentonite, can be readily prepared by the dahlia grower who 
prefers to purchase the separate ingredients for mixing a spray. 
Required are (l) a container of spray water in which are mixed (2) a 
spreading or wetting agent, (3) nicotine sulphate (containing kO per- 
cent of nicotine), which is stirred into the spray solution, and (k) 
dry Wyoming bentonite clay, which should be slowly poured into the 
spray mixture while it is being vigorously stirred. Chemical compounds 
called spreading agents are useful in corn borer sprays because they 
promote penetration of the insecticide into spaces inhabited by young 
larvae. Ordinary soaps are not suitable for this purpose. The most 
effective spreading agents for use in corn borer sprays are highly 
complex chemical products which are sold under various commercial 
names, as Areskap, In-181, In-J+38, Santomerse D, and Ultrawet. 
Proportions of the materials used in home preparation of nico- 
tine bentonite spray are given in the following formulas: 
1. For 50 gallons of spray- 
Water — 50 gallons 
Spreading agent — 3 ounces (dry weight) 1/ 
Nicotine sulphate (UO percent nicotine) - 8 ounces (fluid) 
Wyoming bentonite clay — 2 pounds (dry weight) 
2. For 6 l/U gallons of spray- 
Water ««, 6 1/4 gallons 
Spreading agent *— — l/3 ounce (dry weight) 1/ 
Nicotine sulphate (40 percent nicotine) - 1 ounce (fluid) 
Wyoming bentonite clay — k ounces (dry weight) 
1/ To facilitate accuracy in measuring small quantities of spreading 
agent, a stock solution may be prepared by dissolving 3 ounces of spread- 
ing agent powder in 1 pint (l6 oz.) of water. For example, 8 fluid 
ounces of this solution will then contain the correct amount of spreader 
for 25 gallons of spray, and 2 fluid ounces will be enough for 6 l/k 
gallons of spray. 
