Preliminary work with systemic insecticides on tomatoes.

Systemic insecticides have been defined as those compounds which are absorbed by the plant and translocated in quantities sufficient to make the site of translocation insecticidal for a period of time. Although Hurd-Karrer and Poos (4) reported in 1936 that wheat grow ing on seleniferous soils was not attacked by aphids and shortly after Fulton and Mason (2) produced evidence for the translocation of derris in bean plants, most of the work dealing with field application of systemic in secticides has been published during the last