Mosquito repellent and larvicidal perspectives of weeds Lantana camara L. and Ocimum gratissimum L. found in central India

From an Invasive Weed to an Insecticidal Agent: Exploring the Potential of Lantana camara in Insect Management Strategies-A Review

Lantana camara is weed with a wide range of chemical constituents, including primary and secondary metabolites such as alkaloids, flavonoids, tannins, saponins, and terpenoids. These compounds contribute to its medicinal and pesticidal potential. The essential oils and different solvent fractions derived from L. camara exhibit notable variations in their respective chemical compositions across various plant parts, spatial distributions, and interspecific comparisons. The principal components, notably lantadene A, lantadene B, lantadene C, lantadene D, β-caryophyllene, α-humulene, and several others, constitute a significant portion of the essential oil derived from the leaves and flowers. Researchers have discovered that L. camara oil exhibits potent insecticidal activity against a range of pests, with variations in potency observed across different seasons due to changes in chemical composition. In addition to the essential oils, solvent extracts of L. camara, primarily methanolic extracts of the leaves of this species, demonstrate considerable potential as fumigant and contact toxins for stored grain pests. However, these have been comparatively less characterized with respect to their insecticidal properties, particularly in comparison to the essential oils. Molecular docking studies have demonstrated that phytochemical compounds present in the plants interfere with the activity of several enzymes that are responsible for the growth and survival of insects. For example, compounds such as β-caryophyllene and linalool exhibited a high binding affinity to AChE, thereby enhancing its neurotoxic effects. In conclusion, this review identifies L. camara as a natural insecticide with a complex set of modes of action attributed to its rich phytochemical profile. The integration of traditional knowledge with modern molecular techniques might expose avenues for the sustainable management of pests and control, ultimately making L. camara a key resource for such applications. Further studies are necessary to characterize such bioactive compounds and their uses in controlling pests in agricultural operations.

Extraction, Chemical Composition and Insecticidal Activities of Lantana camara Linn. Leaf Essential Oils against Tribolium castaneum, Lasioderma serricorne and Callosobruchus chinensis

Storage pests and the food spoilage they cause are problems of great concern. Using essential oil obtained from different plants as an insecticide against these storage pests can be considered an environmentally friendly pest management option. Lantana camara Linn. (family Verbenaceae) is a flowering species, and is also a noxious weed that can proliferate well in nearly all geographical habitats. A biopesticide derived from the essential oil extracted from this plant can offer an effective solution for controlling storage pests. The goal of this study is to extract and analyse the chemical composition of essential oil obtained from L. camara leaves, and assess its effectiveness as a bioactive substance against three storage pests: Tribolium castaneum, Lasioderma serricorne, and Callosobruchus chinensis. The yield of essential oil extracted from L. camara leaves was about 0.24 ± 0.014%. By employing the GC-MS technique, the major phytochemicals contained in L. camara leaf essential oil were identified as caryophyllene (69.96%), isoledene (12%), and ɑ-copaene (4.11%). The essential oil exhibited excellent fumigant toxicity (LC50 of 16.70 mg/L air for T. castaneum, 4.141 mg/L air for L. serricorne and 6.245 mg/L air for C. chinensis at 24 h), contact toxicity (LC50 of 8.93 mg/cm2 for T. castaneum, 4.82 mg/cm2 for L. serricorne and 6.24 mg/cm2 for C. chinensis after 24 h) along with effective repellent activity towards the test insects. In addition, the oil showed no significant phytotoxicity on the germination of paddy seeds. This presents the potential to utilize a weed in developing a biopesticide for effectively managing stored product insects because of its strong bioactivity.

Evaluation of the mosquito larvicidal potential and comparative assessment of the juice of Lantana camara Linn and Ocimum gratissimum Linn

In the present study, the larvicidal efficacy of the juices of the weeds Lantana camara Linn (L. camara) and Ocimum gratissimum Linn (O. gratissimum) was evaluated against the larvae of the malaria vectors Aedes aegypti, Anopheles subpictus and Culex quinquefasciatus. The freshly prepared juices of leaves were prepared by grinding them and diluting them at concentrations of 25, 50, 75, and 100 ppm. Twenty larvae of each species were introduced in different sterile Petri dishes in aqueous media under a controlled environment for the assessment of biological activity. The larvicidal activity of both juices was evaluated at 6, 12 and 24 hr post-exposure time points by observing the movement of each larva. The obtained data were subjected to probit analysis to determine the lethal concentrations that kill 50% and 90% (LC50 and LC90) of the treated larvae. The results revealed a noticeable larvicidal activity following 24 h of exposure. The juice of L. camara leaves exhibited an LC50 range of 47.47-52.06 ppm and an LC90 range of 104.33-106.70 ppm. Moreover, for the juice of O. gratissimum leaves, the LC50 range was 42.94-44.91 ppm and the LC90 range was 105.11-108.66 ppm. Taken together, the results indicate that the juices of L. camara and O. gratissimum leaves may be useful as effective, economical and eco-friendly larvicidal agents. However, additional studies are needed to explore the bioactive components of the weeds that exhibit larvicidal activity along with their mode of action.

Invasive plants as biosorbents for environmental remediation: a review

Water contamination is an environmental burden for the next generations, calling for advanced methods such as adsorption to remove pollutants. For instance, unwanted biowaste and invasive plants can be converted into biosorbents for environmental remediation. This would partly solve the negative effects of invasive plants, estimated at 120 billion dollars in the USA. Here we review the distribution, impact, and use of invasive plants for water treatment, with emphasis on the preparation of biosorbents and removal of pollutants such as cadmium, lead, copper, zinc, nickel, mercury, chromate, synthetic dyes, and fossil fuels. Those biosorbents can remove 90-99% heavy metals from aqueous solutions. High adsorption capacities of 476.190 mg/g for synthetic dyes and 211 g/g for diesel oils have been observed. We also discuss the regeneration of these biosorbents.

A review on the efficacy of Ocimum gratissimum, Mentha spicata, and Moringa oleifera leaf extracts in repelling mosquito

Abstract

@@@In recent times, repellents and synthetic drugs have been identified as having negative toxicity effects on humans and the environment. Apart from the unfavourable effects on man and livestock caused by these chemicals-based (synthetic) repellents, they are also expensive, non-biodegradable, and no more effective because mosquitoes are getting adapted. With these drawbacks, an eco-friendly plant-based insecticide as a substitute is needed urgently. This paper reviews the extraction and use of essential oil from the leaves of Mentha spicata, Ocimum gratissimum, and Moringa oleifera as mosquito repellent. Carvone, Eugenol, and 9-Octadecenoic acid were discovered to be the most active components in the M. spicata, O. gratissimum, and M. oleifera extracts, respectively, using gas chromatography-mass spectrometry (GC-MS).

Highlights