Impact of Surfactants on Control of the Root Weevil Diaprepes abbreviatus Larvae with Steinernema riobravis

A filter paper bioassay was developed for testing the efficacy of nematodes and other agents for control of Diaprepes abbreviatus larvae. Surfactants, with and without Steinernema riobravis, were screened first in the filter paper bioassay and then in a potted citrus seedling study. The results of the two assays were in agreement on the relative merits of the compounds tested. Surfactants increased larval mortality at 4 days for the filter paper bioassay and 1 week for the potted plant bioassay. At 8 days for the filter paper bioassay and 2 weeks for the potted plant bioassay, nematodes alone were equal to treatments of nematodes plus surfactants.