Acaricidal activity against Tetranychus urticae and chemical composition of peel essential oils of three Citrus species cultivated in NE Brazil.
The repellency and fumigant toxicities of the peel essential oils of Citrus sinensis var. pêra (LP), C. sinensis var. mimo (LM), and C. aurantium (LL) cultivated in northeast Brazil were evaluated against Tetranychus urticae. Analysis of the oils by GC and GC/MS led to the identification of twenty-eight components, which represented 99.9%, 99.7% and 99.3% of the total constituents of the LP, LM and LL oils, respectively. Limonene was the main component found in all three oils. Other main components were alpha-pinene (1.5% in LP; 1.4% in LM), myrcene (5.7% in LP; 5.9% in LM and 5.6% in LL) and linalool (2.4% in LP; 2.3% in LM and 3.9% in LL). The best repellency action was observed for LM at 2.0%, followed by LL oil and eugenol, both of them at 2.5%. The Citrus oils were less active than eugenol (LC50 = 0.004 microL/L air) and phosphine, which revealed 100% mortality at 2 x 10(-3) g/L (66.7% of the recommended dose). However, the most potent fumigant toxicity was found with LL oil, with an LC50 value of 1.63 microL/L air, followed by the oils from LM and LP with LC50 values of 2.22 microL/L air and 4.63 microL/L air, respectively. The associated fumigant and repellent properties of these Citrus peel oils, particularly those of C. aurantium and C. senensis var. mimo, could be used to advantage for the control of T. urticae.
Araújo
Claudio Pereira
CP
Laboratório de Produtos Naturais Bioativos, Departamento de Química, Universidade Federal Rural de Pernambuco, Recife Pernambuco 52171-900-Recife-PE, Brazil.
da Camara
Claudio Augusto Gomes
CA
Neves
Ilzenayde Araújo
IA
Ribeiro
Nicolle de Carvalho
Nde C
Gomes
Cristianne Araújo
CA
de Moraes
Marcílio Martins
MM
Botelho
Priscilla de Sousa
Pde S
D056810:Acaricides / Q000737:chemistry* / Q000633:toxicity*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001938:Brazil; D002957:Citrus / Q000737:chemistry*; D005054:Eugenol / Q000737:chemistry / Q000494:pharmacology; D005638:Fruit / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D007302:Insect Repellents; D007928:Lethal Dose 50; D009822:Oils, Volatile / Q000737:chemistry* / Q000633:toxicity*; D010720:Phosphines / Q000737:chemistry / Q000494:pharmacology; D040102:Tetranychidae / Q000502:physiology*
D056810:Acaricides; D007302:Insect Repellents; D009822:Oils, Volatile; D010720:Phosphines; D005054:Eugenol