Abstract: The resistance to synthetic pesticides in Anopheles mosquitoes and phytopathogenic fungi constitutes a
major concern. The search for natural pesticides is further encouraged. Essential oils (EOs) of Mentha piperita
and Cymbopogon citratus constitute a potential source of molecules with pesticidal activity but at high doses.
Developing optimized combinations of these natural substances would allow their use as effective pesticides. This
study aims to determine the chemical profile and pesticide efficacy of two types of essential oil combinations of
C. citratus and M. piperita. CG/MS analyses show that the EO obtained by co-distillation of C. citratus and M.
piperita (CC/MP: 80/20) mainly contains citral (49.26%), β-myrcene (10.98%), menthol (5.90%) and menthone
(4.50%). The EO of C. citratus mainly contains citral (74.32%) and β-myrcene (13.66%). M. piperita EO mainly
contains menthol (31.54%), menthone (20.27%), menthofuran (15.10%), and menthyl acetate (8.59%). In the
mixture of the two pure EOs (CC/MP*: 80/20), citral (59.45%), β-myrcene (10.97%), menthol (6.31%) and
menthone (4.05%) were mainly identified. All the EOs inhibited 100% mycelial growth of Macrophomina
phaseolina and Phoma sorghina at concentrations of 0.6 and 0.2%. At the concentration of 0.05%, the inhibition
rates were 49.63, 39.52, 39.52, and 26.33% on M. phaseolina, 41.13, 40.90; 19.67 and 21.50% on P. sorghina,
respectively, for the OEs of CC/MP, C. citratus, M. piperita, and CC/MP*. All the EOs, except that of M. piperita,
caused 100% mortality on the susceptible strain of Anopheles gambiae at a concentration of 1%. However, at the
same concentration, mortality rates were 21.11, 2.47, 8.56, and 3.33% on the resistant strain, respectively, for EOs
of CC/MP, C. citratus, M. piperita, and CC/MP*. EO combinations contain a diversity of molecules that are
obtained by co-distillation of plants and have the best pesticidal properties

C. citratus; M. piperita; Chemical composition; Essential oil combinations; Pesticide.