Objective: In order to control malaria through the reduction of <i>Plasmodium</i> spp vector populations, a study of the sensibility of <i>A. gambiae</i> ss stage II and IV larvae to <I>V.</I> <i>heterophylla</i> and <i>X. aetiopica</i> essential oils was carried out as well as their combined effect evaluated in the University of Ngaoundere, Adamawa region Cameroon from january to february 2020. Methodology: The tests consisted in evaluating the mortality of <i>A. gambiae</i> ss larvae in the presence of diluted solutions of the essential oils following a WHO (2005) methodology. Results: Bioassays revealed that the essential oils of both plants have remarkable insecticidal properties. At 250ppm, essential oils of <i>V. heterophylla</i> and <i>X. aetiopica</i> induced 100% mortality of stage II larvae after 18h of exposure. In stage IV larvae, the same concentration killed 100% of the larvae after 24h of exposure. The combined effect of the essential oils of the two plants on stage II and IV larvae of <i>A. gambiae</i> ss varied according to the proportion of combination made. In stage II larvae, the combination of <i>V. heterophylla</i> 50% and <i>X. aetiopica</i> 50% essential oils showed better efficacy (LC<sub>50</sub>=42.62ppm; LH<sub>50</sub>=03hr23min27sec), followed by that of <i>V. heterophylla</i> 25% and <i>X. aetiopica</i> 75% (LC<sub>50</sub>=44.24ppm; LH<sub>50</sub>=03hr31min21sec) and that of <i>V. heterophylla</i> 75% and <i>X. aetiopica</i> 25% (LC<sub>50</sub>=53.66ppm; LH<sub>50</sub>=05hr07min59sec). A similar trend was observed in stage IV larvae. Conclusion and application: In sum, due to their proven insecticidal properties against <i>A. gambiae</i> ss, the combination of essential oils of <I>V.</I> <i>heterophylla</i> and <i>X. aetiopica</i> should be highly recommended for the development of natural biocides.