Authors:
Etienne V. Tia
, Augustin A. Adima, Jean A. Gnago, Chanta Menut
, Thibaud Martin |
Abstract:
The diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae) is an economically
important pests for cruciferous crops throughout the world. The management is commonly done
based on repetitive applications of chemicals, resulting in environmental pollution and resistance
in pest population.
In the present study, headspace of essential oil (EO) from Melaleuca leucadendron and Hyptis
suaveolens were tested for toxicity and antifeedant effect against larvae of P. xylostella L. The
two EOs obtained by hydrodistillation of Melaleuca leucadendron and Hyptis suaveolens were
found to be toxic with LD50s of 4.86 and 7.53 uL.L-1
air and LD90s of 14.47 and 18.22 uL.L-1
air,
respectively. For a given essential oil, LD50 values were significantly greater than respective
LD90 values. Volatiles from both EO also exhibited antifeedant action against 4th instar P.
xylostella larvae. Long-term effect toxicity against 4th instar larvae of P. xylostella has been
evaluated. Both vapour phases reduced significantly the rate of emergence of adults. The
chemical composition of vapour phase, obtained by headspace (HS) static method, and EO was
determined by gas chromatography coupled with mass spectrometry. The main constituents
found respectively in M. leucadendron EO and HS were 1,8 cineole (50.4%; 48.5%), viridiflorol
(16.4%; 0.7%), ?-pinene (12.4%; 6.8%) and ?-terpineol (8.1%; 14.5%). Those identified in H. suaveolens EO and HS were sabinene (29.9%; 20.2%), ?-caryophyllene (25.2%; 33.9%), ?pinene (6.6%; 4.0%) and terpinolene (5.5%; 7.3%). The biological effect of M. leucadendron
and H. suavolens EOs on P. xylostella and their use in IPM strategy was discussed according to
their chemical composition. |
