Abstract: Plant-derived natural products contain bioactive compounds. One notable example is Argemone mexicana L. (Papaveraceae), a weed native to Mexico that shows significant potential as a pest control agent. This study evaluated the larvicidal activity of aqueous extracts obtained from different plant parts of A. mexicana against the mosquito larvae of Culex quinquefasciatus (Say) (Diptera: Culicidae). The results revealed a clear dose-response relationship, indicating that higher concentrations led to increased larval mortality. In the first five days, the aqueous seed extract showed significant larvicidal efficacy. Probit regression analysis of the observed larval mortality during this period confirmed favorable toxicity, with a measured lethal concentration (LC₅₀) of 11.56 %. This indicates that only small amounts of the extract are required to induce 50 % larval mortality. Although the lethal concentration at 90 % (LC₉₀) was higher at 42.99 %, these values remain adequate for practical applications, particularly considering the product’s natural origin. During the same period, the flower extract also exhibited larvicidal effects, although with lower potency. Higher concentrations of the flower extract maintained significant mortality throughout the first five days. The root extract exhibited intermediate toxicity, with mortality levels proportional to concentration and sustained over time. In contrast, the stem and leaf extracts displayed limited larvicidal activity, even at elevated concentrations. At the end of the experiment (17-days), the extracts demonstrated significant toxicity, with mortality rates exceeding 70 % in all plant parts at the highest concentration tested (100 %). The highest mortality was observed for stem extracts, followed by leaf, and flower. The Relative Growth Index (RGI) confirmed the inhibitory effect of the extracts on larval development, with values below 0.6 in most treatments indicating a moderate response. The seed and root extracts caused the most significant disruption to larval growth. These findings suggest that A. mexicana could serve as a valuable botanical resource for disrupting the life cycle of C. quinquefasciatus and reducing its population. We need further research to optimize formulations and assess their applicability in sustainable vector control strategies because larvicidal efficacy varies depending on the plant part used.
Keywords: Chicalote, Larvicide, Mosquitoes, Weed.
Resumen: Los productos naturales derivados de plantas contienen compuestos bioactivos. Un ejemplo notable es Argemone mexicana L. (Papaveraceae), una maleza originaria de México que muestra un potencial significativo como agente de control de plagas. Este estudio evaluó la actividad larvicida de extractos acuosos obtenidos de diferentes partes de la planta A. mexicana contra las larvas del mosquito Culex quinquefasciatus (Say) (Diptera: Culicidae). Los resultados revelaron una clara relación dosis-respuesta, lo que indica que concentraciones más altas provocan un aumento de la mortalidad larvaria. En los primeros cinco días el extracto acuoso de semillas mostró efectos significativos con la mayor eficacia larvicida. El análisis de regresión Probit para la mortalidad larval observada en los cinco primeros días confirmó una toxicidad favorable, con una concentración letal meida (CL₅₀) del 11,56 %, lo que sugiere que se necesitan pequeñas cantidades del extracto para inducir una mortalidad larvaria del 50 %. Aunque la CL₉₀ fue más alta, del 42,99 %, estos valores siguen siendo adecuados para aplicaciones prácticas, especialmente teniendo en cuenta el origen natural del producto. Para este mismo tiempo el extracto de la flor también mostró efectos larvicidas, aunque con menor potencia. Las concentraciones más altas mantuvieron una mortalidad significativa durante los primeros cinco días. El extracto de la raíz mostró una toxicidad intermedia, con niveles de mortalidad proporcionales a la concentración y sostenidos a lo largo del tiempo. Por el contrario, los extractos del tallo y las hojas mostraron una actividad larvicida limitada, incluso en concentraciones elevadas. Al final del experimento (17 días), los extractos mostraron una toxicidad significativa, con tasas de mortalidad superiores al 70 % en todas las partes de la planta en la concentración más alta probada (100 %). La mortalidad más alta se observó en los extractos del tallo, seguidos de los de las hojas y las flores. El índice de crecimiento relativo (RGI) confirmó el efecto inhibidor de los extractos sobre el desarrollo larvario, con valores inferiores a 0,6 en la mayoría de los tratamientos, lo que indica una respuesta moderada. Los extractos de semillas y raíces causaron la alteración más significativa en el crecimiento larvario. Estos hallazgos sugieren que A. mexicana podría servir como un valioso recurso botánico para alterar el ciclo de vida de C. quinquefasciatus y reducir su población. Se necesita más investigación para optimizar las formulaciones y evaluar su aplicabilidad en estrategias sostenibles de control de vectores, ya que la eficacia larvicida varía en función de la parte de la planta utilizada.
Palabras clave: Chicalote, Hierba, Larvicida, Mosquitos.
Artículos
Effect of polar crude extracts of the mexican prickly poppy on Culex quinquefasciatus mosquito larvae
Efecto de extractos crudos polares de la hierba del cardo mexicano sobre las larvas del mosquito Culex quinquefasciatus
Sociedad Entomológica Argentina
Recepción: 02 Junio 2024
Aprobación: 21 Agosto 2025
Publicación: 30 Septiembre 2025
Arthropod pests, especially insects, cause significant damage and have negative impacts on human health (Sharma et al., 2017). Modified plant compounds have served as the basis for many pesticides. However, the irrational use of these products can lead to environmental contamination of water, soil, and air, as well as poisoning of exposed individuals and increased insect resistance (Rajani & Dave, 2020).
Mosquitoes are important disease vectors that cause significant discomfort and health problems. Important species include Aedes aegypti L. (Diptera: Culicidae), which is responsible for transmitting dengue and dengue hemorrhagic fever (Joyce et al., 2018); A. albopictus (L.), which spreads Chikungunya (Veronesi et al., 2023); and Culex quinquefasciatus (Say), a potential vector for lymphatic filariasis caused by the nematode Wuchereria bancrofti (Araújo et al., 2023). Culex quinquefasciatus is distributed in tropical and subtropical regions. Mosquitoes transmit diseases such as Bancroft's filariasis (Samuel et al., 2004), West Nile virus (WNV) (Sardelis et al., 2001; Pitzer et al., 2009), St. Louis encephalitis virus (Jones et al., 2002), Ross River virus (Lindsay et al., 1993), and Japanese encephalitis virus (Nitatpattana et al., 2005).
Plant-derived compounds offer an ecological alternative for controlling various pests, including mites, rodents, nematodes, bacteria, viruses, fungi, and insects. These compounds have diverse modes of action, making them promising pest control agents (Elshafie et al., 2023). Argemone mexicana L. (Papaveraceae), an invasive weed from Mexico, contributes to global biodiversity loss, because it is a plant that degrades the soil due to its ability to easily absorb nutrients from the soil, which means a loss of quality for nutrient uptake by crops, and also because of its high alkaloid content, it is not useful as feed for livestock (Mooney & Hobbs, 2000). Traditionally, it has been used for its diuretic, purgative, anti-inflammatory, analgesic, and antidotal properties (Bhattacharjee et al., 2006; Dash & Murthy, 2011). Historical uses include laxative effects from ground seeds and eye treatments by the Aztecs (Emmart, 1940; Aguilar et al., 1994). The plant grows in crop fields and abandoned areas (Rao & Dave, 2001). Argemone mexicana is toxic to insects such as Sitophilus oryzae (L.) (Tangadi et al., 2021), C. quinquefasciatus (Ali et al., 2017), and A. aegypti (Warikoo & Kumar, 2013), and nematicidal activity has also been reported (Díaz et al., 2017; Elizondo-Luévano et al., 2020). Studies conducted in Brazil (Indranil et al., 2006) found that methanol-diluted extracts showed significant antibacterial activity. Further research in Morelos, Mexico, showed fungicidal activity against Fusarium oxysporum Schlecht., attributed to alkaloids (Garduno, 2010). Studies by Datkhile et al. (2020) and Jaiswal et al. (2023) highlighted the solvent-dependent variability in the chemical composition and antibacterial activity of A. mexicana extracts.
The insecticidal mode of action of plant extracts is attributed to the presence of secondary metabolites or phytochemicals, which act on multiple molecular targets in insects, affecting their physiology and development. Some compounds interfere with key enzymes, ion channels, and cell membranes or disrupt energy production in mitochondria. Others alter neuronal signaling, leading to neurotoxicity, paralysis, and death. In particular, terpenoids can deregulate endocrine balance and inhibit normal development (Rattan, 2010). Recent studies suggest that A. mexicana contains terpenoids, along with other phytochemicals such as alkaloids, flavonoids, and phenolic compounds (Janani & Gunavathy, 2023); molecules that disrupt vital insect processes (Isman, 2006). This highlights the need for continued research to identify effective control molecules. Various extraction methods using solvents of different polarities, such as water, ethanol, acetone, methanol, chloroform, benzene, petroleum ether, hexane, and ether, have been utilized to isolate active principles, revealing key secondary metabolites with insecticidal properties (Dipanwita & Goutam, 2012; Roopashree & Naik, 2019).
The conventional use of toxic organic solvents poses significant risks to human health and the environment. This has prompted a shift towards more sustainable extraction methods (Bekavac et al., 2024). In this context, aqueous extraction is emerging as a practical and environmentally friendly alternative for isolating bioactive compounds from plants. Building on this, the present study explores the potential of using aqueous extracts from A. mexicana as an affordable and low-risk solution for controlling mosquito larvae. Natural, plant-derived compounds, such as secondary metabolites, offer several advantages over synthetic insecticides, including biodegradability, lower toxicity to non-target organisms, and a reduced likelihood of resistance development (Silvério et al., 2020). Therefore, this research aims to assess the larvicidal efficacy of crude aqueous extracts of A. mexicana against C. quinquefasciatus.
For mosquito rearing, we collected egg rafts of C. quinquefasciatus from a cemetery in Ocotlán de Morelos, Oaxaca, Mexico. We transported the egg rafts to the laboratory and placed them individually in plastic trays measuring 47x35x12 cm, each filled with 300 mL of softened water to facilitate development. We maintained the rearing environment at 26±2 °C, with 60-70 % relative humidity, and a 12/12 hour light/dark photoperiod. Larvae were fed with ground tilapia fish food (Api-tilapia level 1®) until they reached the pupal stage. Pupae were transferred to containers measuring 30×20×20 cm and filled with 300 mL of water. The containers were then placed in entomological cages measuring 60×60×60 cm to allow for adult emergence. Adult males were provided with a 10 % sugar solution diluted in water in a flask, which was sealed with soaked cotton wool and covered with medical gauze. After mating, an immobilized hen was introduced weekly as a source of blood for the female to promote egg-laying. Plastic containers measuring 30x20x6 cm were placed to collect mosquito egg rafts (Manimegalai & Sukanya, 2014). The F10 generation of mosquitoes produced in this environment was utilized in a bioassay (Chaverri et al., 2018).
A total of 1000 grams of fresh plant material was collected (leaf, stem, root, seed, and flower) from cultivated areas in San Jerónimo Taviche, Ocotlán de Morelos, Oaxaca, Mexico (16° 43′ 06.79″ N, 96° 35′ 37.43″ O at 1667 m). Plants were selected based on vigor, absence of disease symptoms, and resistance to insect herbivory (Mitchell et al., 2016). Plants were washed with water and air-dried in the shade. Each plant part was pulverized using a mechanical mill to produce a powder, which was then hydrated (Alamgir, 2017). We collected the plant material in March 2024 from fields of crops, focusing on mature flowering plants. A semi-arid warm climate characterizes the study area, with average temperatures ranging from 18 to 22 °C. The predominant soil type is Luvisol, which covers 47.36 % of the area. Agricultural activities occupy 55.98 % of the land (INEGI (Instituto Nacional de Estadística y Geografía), 2010).
Crude extracts were prepared by placing 60 g of powder from each plant part in a flask and adding enough water to completely cover the material (≈ 120 mL). The mixture was allowed to settle for 24 hours. The solids were then separated from the liquid using a tricot cloth to prevent lumps. The resulting liquid extract (≈ 99.9 mL) was stored at 4 °C until use (García-Vaquero et al., 2020). The aqueous extract obtained after filtration was considered as 100 % concentration. To prepare a 20.0 % concentration, 2 mL of the 100 % aqueous extract was diluted with 8 mL of distilled water. Further dilutions were performed to obtain concentrations of 10.0 %, 5.0 %, and 2.5 % (Khan et al., 2017).
The mortality effect of crude extracts on early second-instar larvae of C. quinquefasciatus was observed for five consecutive days (Rawani et al., 2009). In addition, the effect on the duration of the development periods (second, third, and fourth instars, pupae, and adults) was monitored for 17 days after treatment application. Mortality rates were quantified during the determination of growth rates, with total mortality recorded at the end of the mosquito life cycle. We assessed mortality according to standardized World Health Organization guidelines (Teshome et al., 2023), using two criteria: (1) absence of movements similar to those of the negative control group (distilled water); and (2) lack of response from a larva after being disturbed with a brush in the siphon of its cervical region. The bioassay was conducted using a completely randomized design. Batches of 20 larvae were placed in plastic cups containing 99 mL of distilled water and 1 mL of the assigned treatment. Each treatment was tested with four replications, and two control groups were included. As a positive control, due to its high effectiveness (Yuningsih & Putra, 2025), the organophosphate insecticide Abate (Temephos 1 % granular). For comparison, untreated larvae (distilled water) were used as a negative control. The growth inhibition bioassay lasted from the beginning of the mortality assessment. When the untreated control group reached 90 % to 93 % pupae formation, we recorded the number of live and dead larvae, following the method described by Martínez-Tomás et al. (2009). The collected data were used to calculate the Relative Growth Index (RGI), which serves as a comparative measure of larval growth between a treated group and a control group, using the formula established by Zhang et al. (1993):
The Growth Inhibition Index (GII) was determined by considering the number of live and dead larvae at each developmental stage, according to the following equation:
Where:
is the developmental stage number,
Is the number of live larvae at stage ,
Is the number of dead larvae at stage , considering that if they died at , their actual development only reached stage -1. This means that if a larva dies at a given stage , its actual development is considered to have reached only the previous stage -1,
is the highest attainable stage, defined here as = 5 (2nd, 3rd, and 4th larval instars, pupae and adults),
is the total number of individuals assessed in the treatment.
The RGI effect of crude extract on mosquito larvae was grouped into categories of Arivoli & Tennyson (2013) with some modifications ≠: No activity (RGI ≥ 1.00), +: Low activity (0.75≤RGI≤0.99), ++: Moderate inhibitory activity (0.50 ≤ RGI ≤ 0.74), +++: High inhibitory activity (0.25 ≤ RGI ≤ 0.49), and ++++: Very high inhibitory activity (0.00≤RGI≤0.24). The bioassay was conducted using a completely randomized design.
When analyzing dependent variables such as larvicidal activity and RGI, no corrections were made. The choice was made because of the absence of mortality in the negative control group. Data transformation was considered unnecessary because assumptions of homoscedasticity and normality of errors were satisfied according to Kolmogorov-Smirnov and Bartlett’s tests. Analysis of variance (ANOVA) was done to detect significant differences, and an average comparison was used Tukey (p= 0.05) to assess the effect of different concentrations at each stage of development. Analysis used Minitab v20.3 software for data processing. A Probit analysis was conducted on the mortality data related to the aqueous extract, which showed an efficacy exceeding 50 % by the fifth day of observation. This analysis aimed to estimate the lethal concentration values of LC50 and LC90. The analysis did not include the pure, undiluted extract.
The aqueous extract of A. mexicana seeds showed significant larvicidal activity from the first day across the evaluated concentrations (F= 404.39, df= 6, 20, p< 0.001, r²= 0.9918). This trend persisted until the fifth day (F= 81.27, df= 6, 19, p< 0.001, r²= 0.9625), with a general increase in mortality observed, indicating a cumulative effect of the extract over time. The highest concentrations exhibited greater effectiveness, confirming a clear and sustained dose-response relationship. The aqueous extract of the flowers also showed larvicidal effects, although with less intensity than the seed extract. The 100 % concentration, corresponding to the raw filtrate, was the most effective, demonstrating an increase in mortality between the first and fifth days. On Day 1, only the highest concentrations (100 % and 20 %) resulted in significant mortality, which decreased with the dilutions (F= 346.37, df= 6, 16, p< 0.001, r²= 0.9924). By Day 5, all concentrations exhibited an increase in mortality; however, only the highest concentrations reached levels comparable to those observed. Statistical analysis confirmed the consistency of the effects across treatments (F= 233.92, df= 6, 21, p< 0.001, r²= 0.9887) (Table I).
We observed significant differences in the aqueous root extract from the first day of exposure (F= 2617.37, df= 6,19, p< 0.001, r²= 0.9988). Medium concentrations resulted in intermediate mortality, while the lowest one and the negative control exhibited no effects. By day five, mortality levels remained stable or even increased, continuing to follow the dose-dependent trend (F= 274.13, df= 6,20, p< 0.001, r²= 0.9880). The stem extract showed limited larvicidal activity compared to other parts of the plant. On the first day, only the highest concentrations (100 %, 20 %, and 10 %) resulted in low mortality rates (< 5%), while the 5 % and 2.5 % doses had no observable effect (F= 2639.04, df= 6,20, p< 0.001, r²= 0.9987). By day five, we noted a slight increase in mortality, at intermediate concentrations (F= 450.52, df= 6,16, p< 0.001, r²= 0.9941). The aqueous leaf extract showed moderate larvicidal activity. On the first day, mortality levels remained below 15 %, with significant differences observed between concentrations (F= 1603.83, df= 6,16, p< 0.001, r²= 0.9983). This trend persisted on the fifth day, showing slight but consistent increases in efficacy (F= 471.41, df= 6,18, p< 0.001, r²= 0.9937), although mortality did not exceed the 20 % threshold in any instance.
Mortality (%) of Culex quinquefasciatus second-instar larvae exposed to aqueous extracts from different vegetative parts of Argemone mexicana over five consecutive days
Notes *= Undiluted crude filtrate; C-= negative control (distilled water); C+= positive control (ABATE)
Regression analysis indicates that the aqueous seed extract shows favorable larvicidal toxicity, characterized by a low LC₅₀ value. This suggests that only a minimal quantity of the extract is necessary to induce lethal effects in half of the larval population. Although the LC₉₀ is higher and exhibits greater variability, it remains suitable for practical applications, especially considering that it is a natural, non-synthetic product (Table II).
Probit linear regression analysis for the aqueous extract of Argemone mexicana seeds after five days of exposure
Notes LC= Lethal Concentration (LC); LC50= The lethal concentration that controls half of the mosquito population; LC90= The lethal concentration that controls 90 % of the mosquito population; χ² (df)= Chi-squared test (degrees of freedom); Z-value= Statistical test value (Z-mean); p-value= Probability value
Based on the data presented, in the first five days, extracting from seeds would be the best option, as it demonstrates higher mortality rates compared to other plant parts like roots and leaves, which exhibit lower mortality.
At the end of the experiment, the results confirm the larvicidal potential of A. mexicana aqueous extracts against C. quinquefasciatus larvae. The extracts demonstrated significant toxicity, with mortality rates exceeding 70 % in all plant parts at the highest concentration tested (100 %). The highest mortality was observed for stem extracts (87.50 % at 100 %, 83.75 % at 20 %), followed by leaf (82.50 %), and flower (82.50 %). However, the root and seed extracts did not reach 80 % mortality at the concentrations evaluated, suggesting variability in the efficacy of different plant parts (Table III).
The Relative Growth Index (RGI) for flowers ranged from 0.55 to 0.58, and for leaves, values varied from 0.48 to 0.63, indicating moderate inhibitory activity. Most concentrations (5 %, 10 %, 20 %, and 100 %) of root extract showed high inhibitory activity, with RGI values between 0.45 and 0.57. Similarly, the 10 %, 20 %, and 100 % concentrations of seed extracts exhibited high inhibitory activity, with RGI values ranging from 0.32 to 0.41. Stem extracts only exhibited high inhibitory activity at 5 %, with an RGI value of 0.46.
Overall, a general trend was observed in which the effect of the extracts varied according to concentration and exposure time. In particular, higher concentrations (100 % and 20 %) tended to induce greater mortality compared to lower concentrations (5 % and 2.5 %) and the negative control (C-). Additionally, seed and root extracts exhibited a more pronounced effect on cumulative mortality, reaching significant peaks, especially on days 4 and 5. The trend line (y= 0.2569x) suggests a positive relationship between concentration and cumulative mortality over time.
Relative growth index (RGI) and total mortality rate (%) of Culex quinquefasciatus exposed to aqueous extracts from different vegetative parts of Argemone mexicana
Notes RGI= Relative Growth Index; C-= Negative control; C+= Positive control. Means with different letters in a column and plant part significantly differ from the control group at p< 0.05
The effectiveness of a larvicide lies in its ability to disrupt the development of mosquito larvae, even if its initial impact is not immediate. While some treatments may not achieve high mortality rates in the first days of application, their influence on larval development can prevent the emergence of adult mosquitoes. Their mode of action on larvae includes neurotoxic effects, inhibition of detoxification enzymes, disruption of larval development, and damage to the midgut (Pavela et al., 2019). This disruption is crucial, as it impairs normal larval behavior, such as feeding and respiration, and induces anatomical malformations that hinder metamorphosis. Consequently, many larvae succumb over time due to the cumulative effects of the treatment, thereby reducing the adult mosquito population.
By preventing the larvae from reaching the adult stage, people are protected from mosquito bites and the transmission of diseases. For these reasons, we should consider the potential of a larvicide not only in terms of its immediate efficacy but also in terms of its ability to interrupt the life cycle of mosquitoes. This interruption ensures that the mosquitoes do not reach the adult stage and, as a result, they cannot act as disease vectors.
Our findings are consistent with previous research on the insecticidal properties of A. mexicana and the persistence of its toxicity over time. Sharma et al. (2009) demonstrated the effectiveness of petroleum ether extracts against C. quinquefasciatus larvae, reporting LC50 values of 140.15 ppm at 24 hours and 137.70 ppm at 48 hours.
The chemical composition of A. mexicana provides valuable insights into its larvicidal potential, which is attributed to its rich array of bioactive compounds, including alkaloids, flavonoids, amino acids, and organic acids (Brahmachari et al., 2013; Bhatla & Lal, 2023). Notably, alkaloids such as berberine, sanguinarine, protopine, and argemexicains A and B have been identified in various plant parts (Khan & Bhadauria, 2019; Martínez et al., 2017), exhibiting potent insecticidal properties that position A. mexicana as a promising candidate for mosquito control.
Consistently, Singh et al. (2010) and Xool-Tamayo et al. (2021) reported berberine and sanguinarine as the predominant alkaloids in A. mexicana, highlighting their role in insecticidal activity. These compounds impair nucleic acid and protein synthesis, disrupt cell membrane integrity, and modulate cell signaling pathways, collectively contributing to their larvicidal effects.
The mode of action of alkaloids in insect control varies but involves interfering with vital processes critical for insect survival. Alkaloids can exert neurotoxic effects by disrupting nerve signaling, leading to paralysis, convulsions, and ultimately, the death of the insect (Matsuura & Fett-Neto, 2015; Raisch & Raunser, 2023). In addition, some alkaloids inhibit key enzymes involved in metabolic processes such as digestion, cellular respiration, or neurotransmitter synthesis (Bhatla & Lal, 2023). Alkaloids can disrupt hormone regulation in insects, affecting their development, reproduction, and behavior. They can also cause direct damage to insect cells, resulting in membrane rupture, loss of cell integrity, and cell death (Chowański et al., 2016; Srivastava, 2022).
The Relative Growth Index (RGI) further supports these findings, as larvae exposed to the extracts exhibited significantly lower growth rates compared to the control group. The RGI values for the treated groups were consistently below 0.6, indicating a strong inhibitory effect on larval development. The lowest RGI value (0.32) was observed in larvae exposed to the seed extract at 100 % concentration, suggesting a potential impact on metabolic or physiological processes essential for larval growth. These effects highlight the broader impact of the extracts on mosquito life history traits, influencing development in complex ways (Vantaux et al., 2016).
Additional studies on related species reinforce these observations. Vidal et al. (2009) reported 100 % larval mortality in A. aegypti exposed to ethanolic leaf extracts of Argemone subfusiformis. Similarly, Warikoo & Kumar (2013) demonstrated the insecticidal potential of A. mexicana, finding that hexane root extracts achieved 80-100 % mortality within 24 hours against A. aegypti larvae.
In contrast, our study showed that aqueous root and seed extracts did not reach 80 % efficacy at the tested concentrations. However, the aqueous leaf extract demonstrated 82.50 % efficacy against C. quinquefasciatus larvae at 100 % concentration, suggesting that certain aqueous formulations can achieve results comparable to solvent-based extracts. The lower efficacy of root and seed extracts could be attributed to species-specific differences in susceptibility (Sathantriphop et al., 2006) or variations in the chemical composition of the extracts.
The findings of this study have direct implications for pest management, particularly in the control of C. quinquefasciatus, a vector of significant public health concern. The demonstrated concentration-dependent lethality and growth inhibition of A. mexicana extracts suggest their potential as a botanical alternative for mosquito control. Specifically, the stem extract at 100 % concentration showed the highest mortality (87.50 %) and significant inhibition of larval growth, which could help reduce mosquito populations and their ability to reach the adult stage.
These findings underscore the potential of A. mexicana extracts to be integrated into environmentally sustainable mosquito control strategies. Further research is necessary to optimize the formulation, refine application methods, and validate efficacy through field trials to realize this potential. The aqueous seed extract of A. mexicana has shown promising larvicidal activity against C. quinquefasciatus, a vector for several significant medical diseases, positioning it as a viable alternative to traditional larvicides. The simplicity and low cost of extract preparation also render it workable for implementation in rural and resource-limited areas, particularly within integrated vector management programs that prioritize eco-friendly and sustainable control measures.
redalyc-journal-id: 3220
Thanks are due to the Secretaría de Ciencia, Humanidades, Tecnología e Innovación (SECIHIT), Mexico
fabian.arroyo@secihti.mx
Mortality (%) of Culex quinquefasciatus second-instar larvae exposed to aqueous extracts from different vegetative parts of Argemone mexicana over five consecutive days
Notes *= Undiluted crude filtrate; C-= negative control (distilled water); C+= positive control (ABATE)
Probit linear regression analysis for the aqueous extract of Argemone mexicana seeds after five days of exposure
Notes LC= Lethal Concentration (LC); LC50= The lethal concentration that controls half of the mosquito population; LC90= The lethal concentration that controls 90 % of the mosquito population; χ² (df)= Chi-squared test (degrees of freedom); Z-value= Statistical test value (Z-mean); p-value= Probability value
Relative growth index (RGI) and total mortality rate (%) of Culex quinquefasciatus exposed to aqueous extracts from different vegetative parts of Argemone mexicana
Notes RGI= Relative Growth Index; C-= Negative control; C+= Positive control. Means with different letters in a column and plant part significantly differ from the control group at p< 0.05
