Résumé:
Diptera insects are considered dangerous medicinal and veterinary insects
worldwide, especially mosquitoes (Culicidae). These insects negatively affect human and animal health.
Culiseta longiareolata is one of mosquito species responsible for the transmission of avian Plasmodium
and West Nile virus. Worldwide, several synthetic insecticides have been used to eradicate this
population. Unfortunately, insecticide resistance among mosquito populations has been reported. In this
context, it is necessary to propose new specific alternatives. Among the alternatives, natural products
derived from plants.
Objectives: In this context, the essential oil of the plant juniperus phoenicea was tested in the
laboratory on fourth instar larvae of the species Culiseta longiareolata. Their action has been evaluated
on several aspects: Toxicological and biochemical.
Methods: The essential oil was isolated by hydrodistillation using a Clevenger-type
hydrodistillator for 3 h for extraction. The principle of the toxicity test is to treat fourth stage Culiseta
longiareolata larvae with Juniperus phoenicea essential oil preparations. These preparations have
increasing concentrations (5- 15 ul), dissolved in 1 ml of ethanol. For each concentration did made three
repetitions each comprise 20 larvae. The treatment was applied for 24 h. The quantification of proteins
was carried following the Bradford (1976) method, Carbohydrates were determined following the
Duchateau and Florkin (1959) method and Lipids were measured by the Goldsworthy et al. (1972)
method.
Results and discussion: The toxicological tests made it possible to determine the lethal
concentrations (LC25, LC50 and LC90) of oil extracted from juniperus phoenicea on the newly
exuviated larvae. In a second series of experiments the essential oil significantly reduces the energy
reserves (protein, lipid and carbohydrate) of the larvae
