Rotenone as a Contact Insecticide

Several different types of insects were tested with rotenone in an aqueous suspension and in dust form, the carrier being diatomaceous earth intimately mixed with precipitated rotenone. The aqueous suspensions were highly toxic to aphids, thrips, white fly larvae, leaf hoppers, larvae of beetles, tent caterpillars and culicine mosquitoes. Adult beetles required a much higher concentration. Poor results were obtained against squash bugs, red spiders and mealy bugs; this might have been remedied by the addition of a penetrating and sticking agent, as there is good evidence that the active ingredients of derris are toxic to these insects under optimum conditions of application. The dusts were effective against chicken lice, roaches and cabbage worms, but results against soft bodied sucking insects were not so good.