TY  - JOUR
T1  - Insecticidal Efficiency of Essential Oils of 5 Aromatic Plants Tested Both Alone and in Combination Towards <I>Sitophilus oryzae</I> (L.) (Coleoptera: Curculionidae)
AU - , T.S.L. Ngamo AU - , I. Ngatanko AU - , M.B. Ngassou AU - , P.M. Mapongmestsem AU - , T. Hance 
JO  - Research Journal of Biological Sciences
VL  - 2
IS  - 1
SP  - 75
EP  - 80
PY  - 2007
DA  - 2001/08/19
SN  - 1815-8846
DO  - rjbsci.2007.75.80
UR  - https://makhillpublications.co/view-article.php?doi=rjbsci.2007.75.80
KW  - Antagonism
KW  -crude essential oils
KW  -stored product
KW  -Sitophilus oryzae
KW  -synergy
AB  - To prevent attacks of stored grains by insects pest, rural farmers in the past times, regularly introduce aromatic plants in their granaries. These plants were used alone or associated in groups of 2 or 3 plants. Active compounds of these aromatic plants, mostly present in their essential oils have insecticidal properties. In the present work, crude essential oils of some Lamiaceae, as <I>Hyptis spicigera</I> (Lam.) <I>Ocimum canum</I> (Sims) and <I>Plectranthus glandulosus</I> (Hook); of Rutaceae <I>Vepris heterophylla</I> (Letouzey) and finally of Astareceae <I>Echinops giganteus</I> (Adams) were applied both alone and in balanced combinations on the adults of stored grain pest <I>Sitophilus oryzae</I> (L.) (Coleoptera: Curculionidae) to evaluate their toxicity. These experiments show that all tested essential oils are insecticide except that of <I>E. giganteus</I>. Applied alone, their LD50 vary  from 42.91  ppm  for  the oil of <I>O. canum</I> to 349.8 ppm for oil of <I>V. heterophylla</I>. Applied in balanced combination <I>O.  canum</I>  and <I> H. spicigera</I> expresses no difference (p&lt;0.05) between observed (75.83 ppm) and expected (77.46 ppm) LD50. <I>E. giganteus</I> which was without any insecticidal efficiency synergise the essential oil already active. Moreover, of 20% <I>O. canum </I>in 80% of <I>E.giganteus</I> leads to 100% of mortality. While combined in this same proportion <I>O. canum</I> and <I>P. glandulosus </I>oils also express synergy. <I>V. heterophylla</I>, relatively rich in oxygenated sesquiterpenes increases values of the observed LD50 higher and significantly different (p&lt;0.05) from the expected values.
ER  -