title: Acaricidal activities of Santolina africana and Hertia cheirifolia essential oils against the two-spotted spider mite (Tetranychus urticae).
abstract: BACKGROUND
  Many plant essential oils show a broad spectrum of activity against pests. This study investigated the effects of two essential oils on Tetranychus urticae, one of the most serious pests in the world.
  
  
  RESULTS
  The chemical composition of the two oils was characterised by GC-MS. The most abundant component in the Santolina africana (Jord. & Fourr) oil was terpinen-4-ol (54.96%), while thymol (61%) was prevalent in the Hertia cheirifolia (L.) oil. Mortality and fecundity were measured upon treatment with oil concentrations ranging from 0.07 to 6.75 mg L(-1) with a Potter spray tower. Mite mortality increased with oil concentration, with LC(50) values of 2.35 mg L(-1) for S. africana and 3.43 mg L(-1) for H. cheirifolia respectively. For both oils, a reduction in fecundity was observed at concentrations of 0.07, 0.09 and 0.29 mg L(-1) . Artificial blends of constituents of oils were also prepared and tested with individual constituents missing from the mixture. The results showed that the presence of all constituents was necessary to equal the toxicity of the two natural oils.
  
  
  CONCLUSIONS
  S. africana and H. cheirifolia oils can provide valuable acaricide activity with significantly lower LC(50) values. Thus, these oils cause important mortality and reduce the number of eggs laid by females.
authors.affiliation: Biodiversity Research Centre, Université Catholique de Louvain, Louvain-la-Neuve, Belgium. sabine_bio5@yahoo.fr
authors.forename: Sabrine
authors.initials: S
authors.lastname: Attia
authors.forename: Kaouthar L
authors.initials: KL
authors.lastname: Grissa
authors.forename: Anne C
authors.initials: AC
authors.lastname: Mailleux
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Heuskin
authors.forename: Georges
authors.initials: G
authors.lastname: Lognay
authors.forename: Thierry
authors.initials: T
authors.lastname: Hance
mesh_terms: D056810:Acaricides / Q000737:chemistry / Q000633:toxicity*; D000818:Animals; D019659:Asteraceae / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005298:Fertility / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry / Q000633:toxicity*; D040102:Tetranychidae / Q000187:drug effects* / Q000502:physiology
chemical_list: D056810:Acaricides; D009822:Oils, Volatile