ABSTRACT
BACKGROUND & OBJECTIVES: Recently, the use of biodegradable and environment friendly plant-based bioinsecticides has received a great deal of attention from researchers to control insect disease vectors. The aim of this research is to determine the larvicidal efficacy of Ruta graveolens essential oil against third instar larvae of two species of mosquito (Culex pipiens and Culiseta longiareolata) and a biological model Drosophila melanogaster. METHODS: Culiseta longiareolata and Culex pipiens larvae were collected from untreated areas located in Tebessa and Drosophila melanogaster, the wild strain collected from rotten apples in the Tebessa region. Ruta graveolens essential oil has been tested at different concentrations between 2.5µ/mL and 140µL/mL against third instar larvae of the three species under standard laboratory conditions according to the recommendations from the Word Health Organization. The effects were examined on mortality, growth and the main components (proteins, carbohydrates, lipids). RESULTS: The essential oil showed larvicidal activity with LC50 and LC90 values (10.85µL/mL, 70.95µL/mL and 39.4µL/mL), (26µL/mL, 144.5µL/mL and 89.57µL/mL) against third instar larvae of Drosophila melanogaster, Culex pipiens and Culiseta longiareolata respectively. In addition, it disrupted the growth and several morphological malformations were observed. It also affected growth and the main components (proteins, carbohydrates, lipids). INTERPRETATION & CONCLUSION: The essential oil affected growth and energy reserves for all three species. The results indicated that the essential oil of Ruta graveolens has good potential as a source of natural larvicides.
Subject(s)
Aedes , Culex , Culicidae , Insecticides , Oils, Volatile , Ruta , Animals , Drosophila melanogaster , Mosquito Vectors , LarvaABSTRACT
Objective:To evaluate the activity of spiromesifen against the most abundant and investigated mosquito species,Culiseta longiareolata Aitken,1954 (Diptera,Culicidae).Methods:Culiseta longiareolata larvae were collected from untreated areas located at Tébessa (Northeast Algeria).A commercial formulation of spiromesifen (Oberon(R) 240 SC) was tested at different concentrations ranging between 238 and 1428 μg/L on newly molted fourth-instar larvae under standard laboratory conditions according to Word Health Organization recommendations.The effects were examined on the mortality,the morphometdc measurements,two biomarkers (catalase and malondialdehyde),and the biochemical composition of larvae,respectively.Results:The compound exhibited insecticidal activity.Moreover,it disturbed growth and several morphological aberrations were observed.It also affected body volume,biomarkers and contents of carbohydrates,lipids and proteins.A marked effect on lipids and malondialdehyde was noted,confirming its primary mode of action on lipid synthesis.Conclusions:Spiromesifen appears less potent than other insecticides tested such as the insect growth disruptors.
