Abstract:

Caryopteris Ãclandonensis A. Simmonds ex C. H. Curtis 'Durio' Pink Chablisâ¢, (Lamiaceae) a pink-flowered cultivar distinctive among the typically blue-flowered cultivars of bluebeard, is valued as a small, deciduous shrub in the landscape for its mounded growth habit, showy flower display in summer, and attractiveness to insect pollinators. As part of a broader research program examining aromatic compounds from ornamental species as natural alternatives to synthetic chemicals for control of insect pests, the essential oil of Pink Chablis⢠bluebeard was investigated for its chemical composition and bioactivity as a repellent and larvicide against the yellow fever mosquito [Aedes aegypti (L.) (Diptera: Culicidae)]. Essential oil from the aerial parts of this mildly aromatic ornamental species was extracted by water distillation and analyzed by gas chromatography and gas chromatography mass spectrometry. The primary compounds in the essential oil were α-copaene (8.3%), limonene (7.2%), and δ-cadinene (6.3%), followed by trans-p-mentha2,8-dien-1-ol (4.6%), trans-p-mentha-1(7),8-dien-2-ol (4.5%), cis-p-mentha-2,8-dien-1-ol (4.0%), and hotrienol (3.8%). Against the yellow fever mosquito, the essential oil exhibited mild repellency compared to DEET (N,N-diethyl-3-methylbenzamide) as a reference standard. It exhibited weak activity as a mosquito larvicide.

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