Résumé:
Insect pests can cause considerable damage to their host plants. This study focused on
two harmful insects that cause considerable damage to plants; the processionary caterpillar
that attacks the needles of the Aleppo pine and the green citrus aphid, the main vector of
viruses and which causes a general weakening of citrus trees.
This work is part of the search for natural substances of plant origin capable of replacing
chemical pesticides. He is interested in testing the larvicidal effect of different doses of
essential oils (HEs) from two aromatic plants (Eucalyptus sp. and Mentha spicata) on the two
aforementioned insects.
For the study on the Aleppo pine processionary, we could not reach the required objective due
to the high mortality of the controls. While for the green citrus aphid, we were able to
highlight the insecticidal effect of the essential oils of the two plants tested.
The results obtained in vitro revealed a strong insecticidal activity on the green citrus aphid.
The use of essential oils of Eucalyptus sp. and Mentha spicata, made it possible to observe
mortality rates of greater than 75% for the three high doses tested (D1=1%, D2=0.5% and
D3=0.25%) on the third day. The observations show that mortality increases when the dose is
raised, and that mortality in batches treated with Eucalyptus sp HE. is more important than
those treated with the HE of the Mentha spicata.
