Phytochemical investigation and evaluation of acaricidal activity of Ammi crinitum Guss. against the two-spotted spider mite Tetranychus urticae Koch

Ammi crinitum Guss., a species belonging to the Apiaceae family, is an exclusive and endemic plant of the Sicily region, Italy. Considering the limited scientific attention given to A. crinitum, herein, for the first time, metabolite profiles of polar extracts (MeOH) of the aerial parts, flowers, and roots were investigated by liquid chromatography coupled to electrospray ionization and high resolution multiple-stage mass spectrometry (LC-ESI/HRMSn), allowing the identification of 32 compounds, never identified in A. crinitum. Metabolites belonging to the classes of organic acids, megastigmanes, phenylpropanoids, iridoids, flavonoids, coumarins, triterpenoids, and polar lipids were putatively identified; in particular, several compoundsare reported here for the first time in Ammi genus. Considering the increasing interest for the development of botanical insecticides, the acaricidal activity of A. crinitum against the two-spotted spider mite Tetranychus urticae Koch was evaluated. Although all extracts showed promising acaricidal activity, the most effective was the extract obtained from the aerial parts. The lowest LD50 and LD90 values of 2.3 and 77.3 μg‧cm−2 were estimated for this extract from aerial parts, although this LD50 was statistically identical to the LD50 of the roots extract. The extract from aerial parts not only caused the mortality of T. urticae adults, but also inhibited the fertility and fecundity of females, even when a dose of 5 μg‧cm−2 was applied. Based on our experiments, MeOH extracts from aerial parts biomass of A. crinitum can be proposed as a perspective source of active substances of potential botanical acaricides.