Abstract

Tetranychus urticae is an economically important pest for different commercial crops and is traditionally controlled with synthetic chemical products that are usually toxic. Therefore, alternative strategies are implemented to allow producers to meet the phytosanitary requirements demanded by quality seals. One of these alternatives is the use of plant extracts. The aim of this study was to determine the effect of median lethal dose of Solanum nigrum extracts on the mortality and fertility of T. urticae females under laboratory conditions. Liquid chromatography-mass spectrometry (LCMS)-based chemical characterization of the ethanol extract of S. nigrum leaves was also conducted. The immersion technique and direct application on rose leaves were used to evaluate the effects of seven doses (1 to 1000 µg/mL) of the ethanol extract of S. nigrum leaves on T. urticae females under laboratory conditions. The mortality and oviposition of spider mites were recorded at 24, 48 and 72 h. The effects of seven concentrations of ethanol extract were evaluated on phytophagous females. The LC₅₀ value was 279.69±20.59 µg/mL after 72 h. The test extract also caused a reduction in oviposition. The main components in the leaf extract of S. nigrum were found to be flavonoid and alkaloid-related compounds. The ethanol extract of leaves of S. nigrum showed high potential as an effective management strategy against T. urticae under laboratory conditions.

Key words: Spider mites, LC₅₀, rose crop, ethanol extracts, liquid chromatography-mass spectrometry (LC-MS).