A Preliminary Report on the Toxic Value of Fluosilicates and Arsenicals as Tested on the Plum Curculio

Abstract

Sodium fluosilicate without lime, both as dust and at the rate of 2 pounds to 50 gallons of water, was the most toxic to the plum curculio, Conotrachelus nenuphar, of all the insecticides tested. That insecticide without lime was also found to be very toxic to peach foliage and fruit. Lime corrected the burning effect of sodium fluosilicate, but these tests showed that lime largely destroyed its toxicity as an insecticide for the plum curculio. Arsenate of lead with lime, either as dust or as a spray, was found to be more toxic to the curculio than any of the insecticides tested except sodium fluosilicate without lime. The relative toxic value of the other insecticides tested against the plum curculio was found to have the following order, the most toxic being placed first: barium arsenate, tricalcium arsenate, zinc arsenate, magnesium arsenate, manganese arsenate, aluminum arsenate, sodium fluosilicate with lime, calcium fluosilicate compound, and scorodite.