An acaricide-treated net to control phytophagous mites

Abstract

A new technique to control phytophagous mites was tested in West Africa on the African eggplant Solanum macrocarpon. This technique consisted of covering plants with a net impregnated with the acaricide dicofol. The net was applied during the night to protect the net fabric and the active ingredient from UV degradation and to avoid interference of the net with overhead watering. The technique was evaluated in three trials at the INRAB research station and in a grower's field in 2006 and 2007. Results showed that the broad mite Polyphagotarsonemus latus (Banks), the major pest of S. macrocarpon which causes severe damage to leaves, and spider mites ( Tetranychus spp.), were completely controlled by the dicofol-treated net. Very few mites and practically no mite injury were observed on plants covered with the dicofol-treated net compared to 12–94% damaged leaves in the unprotected control plots. The acaricide-treated net was as efficient when used temporarily (once every three nights) as when used every night. No difference in the percentages of leaves damaged by mites was apparent at harvest between plots covered with a non-acaricide deltamethrin-treated net (40%) and unprotected control (32%). This new concept of mite control using an acaricide-treated net temporarily covering vegetable crop appears to be an efficient tool which is easy to use. It can be used repeatedly reducing costs and poses a very low risk of environmental pollution when used in the dry season or in greenhouses.