Essential oils (EOs) represent innovative and safe botanical pesticides to be exploited in different fields, including
agriculture, being often obtained by cheap and easily available plant crops. However, their use is threatened by
some limits, which are mainly linked to their physico-chemical properties. In this regard, the use of nanoemulsions (NEs) usually enables to overcome these limits but often also to improve the biological activities of
these products. Bunium persicum (Boiss.) B Fedtsch. and Ziziphora clinopodioides Lam. are two aromatic plants of
economic interest well known for their traditional food and medical uses. Their EOs exhibited several biological
properties, including a remarkable insecticidal activity against different targets. Here, the chemical analysis of
the two EOs revealed the predominance of γ-terpinene (35.8%), cumin aldehyde (16.6%), γ-terpinen-7-al
(14.0%), and α-terpinen-7-al (11.7%) for B. persicum, and pulegone (55.6%), piperitenone (12.8%), and isomenthone (8.0%) for Z. clinopodioides. NEs were successfully obtained by high-pressure homogenization or
ultrasonication method, using polysorbate 80 as emulsifier. The EOs and their 10% NEs were evaluated against
larvae and pupae of Culex quinquefasciatus Say mosquitoes. In detail, both EOs exhibited a good larvicidal efficacy (LC50 of 35.8 and 68.9 µL L− 1 for B. persicum and Z. clinopodioides, respectively). Bunium persicum EO NE
showed higher efficacy than the EO alone (LC50 = 290.4 µL L− 1
), considering that only the 10% of the EO was
encapsulated. Conversely, Z. clinopodioides NE showed the same efficacy than the EO alone (LC50 of 759.8 µL
L− 1
). In addition, both NEs displayed significantly better sublethal toxicity compared with the EOs. Moreover,
even if no significant mortality was detected in the pupal stage, only 12% of the larvae pupated and emerged as
adults in the case of the NE from B. persicum. In conclusion, both EOs and their NEs could be promising candidates for the