The purpose of this study was to make preliminary determination of the effectiveness, economy, and optimal application rate of pyrethrum emulsion larvicide in Georgia situations subject to effective anopheline control by Paris green. The work was inspired by the recommendation of a Federal Agency suggesting that pyrethrum emulsion larvicides be used at local expense in place of drainage for malaria-mosquito control in Georgia. This recommendation, as far as we can determine, was made in the absence of any published report of the trial of emulsified pyrethrum as (1) an anopheline larvicide under natural, southern U. S. breeding conditions, (2) its minimum lethal application rate, and (3) its larvicidal efficiency and cost in comparison with that of other established and commonly-used larvicides.
This investigation is one phase of a divisional program of research on larvicides.
The pyrethrum-soap-emulsion stock mixture was prepared according to the New Jersey Agricltural Experiment Station publication entitled “Oil Pyrethrum Extract Emulsion” (1).