Abstract

SOTO G, Alberto; MOREIRA, Márcio Dionizio  and  PALLINI, Angelo. ANALYSIS OF THE CHEMICAL COMPOSITION OF THE TETRANYCHUS EVANSI BAKER & PRITCHARD AND TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) CUTICLE. Bol. Cient. Mus. Hist. Nat. Univ. Caldas [online]. 2011, vol.15, n.2, pp.171-190. ISSN 0123-3068.

The analysis of arthropods chemical composition is important in taxonomy for recognition of species difficult to differentiate, in ecology, for behavioral analyses, and in selectivity studies of artificial and natural compounds, and, therefore, it is important for pest control. The objective of this study was to evaluate the chemical composition of the T. urticae and T. evansi mites cuticle. Chromatographic analyses of extracts were performed by gas chromatography coupled to mass spectrometry (CGMS). Identification of compounds was based on the comparison of retention times with standards, on the Kovats' index calculation and the analysis of mass spectra obtained for each registered peak on the chromatogram. Relative concentration of compounds present in the cuticle, the polarity of these compounds and their total relative concentration, and the differential presence of compounds in the cuticle of the two mite species were evaluated. The most abundant compounds in the cuticle of both mite species were hexadecanoic acid (palmitic acid), 9,12-octadecadienoico acid (linoleic acid), 9,12,15-octadecatrienoic acid-methyl ester (methyl linoleate) and octadecanoic acid (oleic acid or stearic). T. urticae cuticle has from 2.07 to 3.67 times more hexane extractable compounds than T. evansi cuticle . The total polar compound concentration was 2.15 to 3.71 times higher in T. urticae and the quantity of the most abundant compounds present in both species was 2.34 to 5.66 times higher in T. urticae.

Keywords : mass chromatography; mass spectrometry; Kovats' index; selectivity.

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