Abstract

ABSTRACT
A survey of immature Culicidae was conducted in various habitats of Souk-Ahras region (North-East Algeria) between December 2018 and November 2019. The results of the identification of mosquitoes collected in the different study sites show the presence of 19 species of Culicidae divided into two main subfamilies namely Culicinae (84.21%) and Anophelinae (15.79%), under 5 genera: Culex (85%), Culiseta(16%), Anopheles (16%), Aedes (5%) and Uranotaenia(5%). Among the identified species, four new species for the Souk-Ahras region were reported, Cx. territans, Ae. flavescens, Ur. unguiculata, An. claviger, Cx. adairi and An. marteri. Among others, our results show the predominance of the species Cxpipienswith an abundance rate of 69.63%. In addition, to better understand the spatial distribution of mosquitoes in relation to climatic factors, the analysis focused on the correlation between temperature, rainfall, humidity and mosquito abundance. The larvicidal property of the plant Tecoma stans (Bignoniaceae) has been recently discovered in science. The toxicity presented by this plant towards the fourth stage larvae of the most common mosquito species in the Souk-Ahras region Culex pipiensL. (Diptera: Culicidae) is the central context of our present study. The methodology adopted for this includes the realization of gas chromatography-mass spectrometry (GC-MS) on ethanolic extracts of leaves and flowers of Tecoma stans for its chemical characterization and detection of active constituents and the larvicidal toxicological study of these extracts on growth and development, the reproductive potential and the effect on the biomarkers of neurotoxicity (acetylcholinesterase) and detoxification(glutathione S-transferase) and for that, two lethal concentrations (LC30 and LC50) were applied on L4 during 24h. Qualitative and quantitative phytochemical analysis (GC-MS) of leaf extract revealed the presence of 9 phytoconstituents with 2-[4-cyclohexylbutanoylamino]-3-chloro-1,4-naphthoquinone (36.24%) and 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester (22.65%) as the main components. Thus, 13 constituents for the flower extract, 4-Amino-2(1H)-pyridinone (35.38%), 2-(Acetoxymethyl)-3-(methoxycarbonyl)biphenylene (11.80%) as major components. Overall, ethanolic extracts of T. stans cause a decrease in weight growth and an imbalance in the metabolic profile of the mosquito. They alter the reproductive traits of the adults; negatively affecting gonad size, body mass, fecundity and fertility, which has a negative impact on the survival of their offspring. The extracts moderately inhibit acetylcholinesterase (AChE) and cause a significant increase in glutathione S-transferase (GST) activity.
Keywords :Mosquito, Culex pipiens, Tecoma stans, ethanolic extracts, toxicity.

Information

Item Type:	Thesis
Divisions:	» Faculty of Natural Sciences and Life
ePrint ID:	3538
Date Deposited:	2022-11-07
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/3538

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