Insecticidal and Genotoxic effects of some indigenous plant extracts in Culex quinquefasciatus Say Mosquitoes

Abstract

Five different weed plants viz. Convulvulus arvensis, Chenopodium murale, Tribulus terrestris, Trianthema portulacastrum, and Achyranthes aspera were investigated for their entomocidal and genotoxic effects against Culex quinquefasciatus mosquitoes. High mortality was observed at 72 hours in a dose dependent manner. Among all the tested plants, A. aspera was found highly significant which showed 100% mortality at 250 ppm after 72 hours with LC 50 of 87.46, 39.08 and 9.22 ppm at 24, 48, respectively. in combination with Bacillus thuringiensis israelensis (Bti); A. aspera also caused 100% mortality at 250 ppm concentration after 72 hours (LC 50 8.29 ppm). Phytochemical analysis of all the tested weed plants showed the presence of flavonoids, saponins, tannins, steroids, cardiac glycosides, alkaloids, anthrequinones and terpenoids. Random Amplification of Polymorphic DNA-Polymerase chain reaction (RAPD-PCR) and comet assay were performed to assess the genotoxic effect of A. aspera but no change in DNA profile was observed. Furthermore, FTIR showed the presence of phenolic compounds in A. aspera extract. It is suggested that certain phenolic compounds such as flavonoids modulate the enzymatic activity and, hence, cause the death of larvae of Cx. quinquefasciatus. Altogether, current study would serve as an initial step towards replacement of synthetic insecticides to plant-microbe based biopesticide against Culex mosquitoes in future.Mosquitoes are reported to cause nuisance to humans and transmit several viral and protozoan diseases of public health concern worldwide. These are female mosquitoes which make a bite during their search for blood meal before oviposition which thus, increases their tendency to transmit several diseases including malaria, filariasis, dengue fever, japanese encephalitis, chikungunya, zika virus and yellow fever. These diseases make life at risk of millions of people particularly in subtropical/tropical world 1,2 . Of various mosquito species, Cx. quinquefasciatus transmits various diseases i.e., West Nile virus, Japanese encephalitis, filariasis, bancroftian filariasis (Wuchereria bancrofti), St. Louis encephalitis, and avian malaria 3 . In southern United States, St. Louis virus and West Nile virus (WNV) were transmitted by Cx. quinquefasciatus 4,5 . Almost 120 million people are affected annually only by lymphatic filariasis, whereas 1.3 billion are at risk resulting in nearly $1.3 billion loss of productivity per year 6 . Similarly, three billion individuals are at risk of being infected by Japanese encephalitis with 30,000-50,000 reported cases every year in disease endemic areas 7 . Besides disease transmission in humans; Cx. quinquefasciatus is also responsible for transmitting several diseases to livestock and companion animals viz. Rift Valley fever, canine dirofilariasis (dog heartworm), avian malaria, avian pox, and West Nile encephalitis which lead to high mortalities or decreased productivity 8 . open Scientific RepoRtS | (2020) 10:6826 | https://doi.org/10.1038/s41598-020-6381...

Larvicidal and adulticidal effects of some Egyptian oils against Culex pipiens

“…Green tea oil is a highly effective larvicide in this study contains a high amount of polyphenols that have antioxidant activity. A similar finding was reported 59 . Our data indicated that green tea oil also contains polyphenols as Gallic acid, Catechin, Methyl gallate, Coffeic acid, Coumaric acid, Naringenin, and Kaempferol which might aid in its insecticidal effect.…”

Activation of the Oxidative Stress in Culexquinquefasciatus by the Augmented Productionof Reactive Oxygen Species (ROS) in responseto Stachytarpheta jamaicensis Exposure

“…5,5,23,25,26 Altogether, the present status of vector control research urges us to find out cost-effective, environmentfriendly, target-specific and biodegradable natural insecticides against Culex quinquefasciatus mosquitoes. 8,24 Previously, 15 reported on the entomocidal potential of five different plants such as Achyranthes aspera, Chenopodium murale, Trianthema portulacastrum, Convulvulus arvensis, and Tribulus terrestris against Culex quinquefasciatus. In agreement with their findings, 20 reported the extensive larvicidal potential of Plectranthus amboinicus with an LC50 of 147.40 mg/L.…”

The Antibacterial and Larvicidal Potential of Bis-(2-Ethylhexyl) Phthalate from Lactiplantibacillus plantarum

“…After the development of adults from the pupa in 2–3 days, the male adults were fed with a 10% sucrose solution soaked in cotton in the beaker and kept in a cage. Meanwhile, the female adults were blood-fed for the development of oviposition by keeping a rat in the cage [ 11 ].…”

“…The beakers were labeled properly and covered with muslin cloth. Each test was performed in triplicate with a control group and their mortality was recorded after 24, 48, and 72 h. The immovable dead larvae that showed no response with sharp pin probing were removed from beakers and stored in microcentrifuge tubes containing ethanol [ 11 ] to determine their Acetylcholinesterase (AChE) inhibition activity and DNA damage by comet assay.…”

“…Many synthetic insecticides, such as organophosphates (fenthion and temephos), are used to control biological vectors, but their use as an insecticide has been prohibited due to associated health risks [ 10 ]. Moreover, the continuous use of synthetic insecticides results in resistance development within mosquitoes [ 11 ]. Therefore, the development of eco-friendly and target-specific antibacterial and larvicidal agents for the control of pathogens and mosquito larvae is of primary importance [ 12 ].…”