Larvicidal activities of three plants against filarial vector Culex quinquefasciatus Say (Diptera: Culicidae)

Abstract

The methanol leaf extracts of Glochidion neilgherrense, Cinnamomum wightii and Leucas linifolia are highly toxic even at low doses proven to be useful for larvicidal, pupicidal and adulticidal activity against Culex quinquefasciatus. The extraction of Glochidion neilgherrense, Cinnamomum wightii and Leucas linifolia are dose dependent and the mortality of the larvae increases as the doses of the sample were increased. Among all the instars, the fourth instar larvae were less susceptible to the plant extracts than first instar larvae. The mortality caused by some neural and muscular disturbance by the presence of variety of active compounds such as cytotoxic diterperiods, lactones and flavonoids in the plants. It was observed that the increase in concentration of extracts increased the potential activity of biocides against Culex quinquefasciatus. The decrease in egg hatchability was found to be dose dependent. There was increase in the larval-pupal duration, developmental duration, decrease in fecundity and egg hatchability, biting deterrency, in our study. The extract showed ovipositional deterrence and effective repellence against Culex quinquefasciatus at different concentration, with the observation on that maximal egg were laid in lower concentration of the extract and control. In oviposition deterrent and gravid mortality assay, the OAI values also indicated that the gravid and oviposited females were repelled by extracts and the reduced oviposition was due to the greater mortality of adults before they oviposited, caused by treatment of plant extract which contained of variety of active compounds. All the concentration of plant extracts hared promising mosquito repellency properties when tested against the adult mosquitoes of Culex quinquefasciatus. In the biting deterrency results, increasing in the concentration of plant extracts from 1% to 4% was found to increase the biting deterrency percentage.

Studies on Mosquitocidal and biological activity of endemic plants of Nilgiris Hills against filarial vector, Culex quinquefasciatus (Say) (Insecta: Diptera: Culicidae)

“…Further, Prathibha et al (2011) have reported the larvicidal efficacy of Euodia ridleyi against C. quinquefasciatus. Rawani et al (2009) established the larvicidal properties of crude extracts of Carica papaya, Murraya paniculata and Cleistanthus collinus against C. quinquefasciatus and suggested that the presence of many bioactive principles such as steroids, alkaloids, terpenes, saponins, etc. which may be responsible for their biocontrol potentiality.…”

Nano-Insecticides for the Control of Human and Crop Pests

“…Rawani et al [ 61 ] established the larvicidal properties of crude extracts of Carica papaya , Murraya paniculata , and Cleistanthus collinus against the mosquito, Culex quinquefasciatus , and suggested that the presence of many bioactive principles such as steroids, alkaloids, terpenes, and saponins may be responsible for their biocontrol potential. C. occidentalis -synthesized AgNPs were highly toxic against A. stephensi larvae and pupae, even when tested at very low doses.…”

Mosquito larvicidal potentiality of wild turmeric, <i>Curcuma aromatica</i> rhizome, extracts against Japanese Encephalitis vector <i>Culex vishnui</i> group

“…petroleum ether, n-hexane, ethyl acetate, chloroform: methanol (1:1 v/v), acetone and absolute alcohol from non-polar to polar fashion were passed through the column one after another with the same plant materials. The extraction period was fixed for 72 h , 2013, Rawani et al, 2009 for each solvent with 8 h maximum a day. The extractives were collected from the still pot chamber and concentrated through evaporation.…”