Evaluation of Insecticidal and Genotoxic Activities of some Essential Oils Against Culex pipiens

Abstract

Mosquitoes constitute a major public health problem as vectors of serious human diseases. Culex pipiens, a domestic mosquito, has been incriminated as the main vector of bancroftian filariasis, the Rift Valley fever and West Nile virus. Mosquito control is a vital public-health practice throughout the world. Chemical insecticides that used to help control mosquitoes lead to environmental threat. These chemicals effects on non-target organisms and development of insect resistance. The well-known hazards of used chemical insecticides stimulated the interest to effective alternative chemical insecticides. Thus, the environmental friendly and biodegradable natural insecticides of plants origin have been receiving attention as an alternative green.Botanical insecticides are Biodegradable, non- side effect toxic to non target organisms, human, animal and environment. Essential oils and their components are potential alternatives to the use of chemical insecticides for Culex pipiens control.

Natural essential oils are extracted from different plant parts of aromatic plants Essential oils which are also known by the names aromatic oils and fragrant oils.Essential oils are commonly extracted through steam distillation.

The aim of this study was to investigate the insecticidal activities of clove oil (Syzygium aromaticum), eucalyptus (Eucalyptus globulus) and rose water (Rosa damascena) on Culex pipiens adults and larvae by monitoring biological, biochemical and genotoxic .

Essential oils compounds were identified by GC-MS analysis. The main components of clove essential oil were Eugenol(88.08%) , Eugenolacetate(3.40%) and b-Caryophyllene(3.24%).The main components of eucalyptus essential oil were 1, 8-eucalyptol(46.76%) and D-Limonene (9.61%) . The main components of rose essential oil were nerol(20.88%), Citronellol(18.05%) and Geraniol (10.42%).

Fumigation bioassay was performed against Culex pipiens adults. Different concentrations of each tested aromatic substances were incorporated in a cotton yarn. After 1h , 6h and 24h of exposure ,mortality was assessed in each group. Eucalyptus oil was found to have the highest toxicity (LC50: 0.108%) and rose water have the lowest toxicity (LC50: 0.732% ) after 24h.