The invasive weed Parthenium hysterophorus has severely disrupted ecosystems worldwide, driven by its persistent seed bank and phytotoxic compounds that suppress surrounding vegetation and negatively impact herbivorous mammals. It is widely assumed that wild ungulates avoid parthenium weed-dominated areas due to its presumed unpalatability and toxicity, but direct evidence is limited. We experimentally tested whether ungulates in an African savanna actively forage on parthenium weed by contrasting herbivore foraging in mechanically cleared and controlled areas using exclosures in parthenium-invaded areas. We also assessed whether reduction in body condition scores was associated with foraging on parthenium weed, and whether herbivory suppresses parthenium weed regrowth. Our experimental results show that ungulates foraged on parthenium rosettes without apparent negative impacts on body condition. Notably, herbivore activity significantly reduced parthenium cover in cleared areas. These findings reveal a previously undocumented potential for leveraging wild ungulate herbivory as a biocontrol mechanism for managing parthenium weed invasions.

Insect-plant interactions are fundamental ecological processes that form plant survival and insect community dynamics. Parthenium hysterophorus L. (Asteraceae), commonly known as congress grass, is an aggressively invasive weed that creates significant ecological and agricultural challenges. This study aimed to record the diversity of insect visitors associated with Parthenium hysterophorus, their spatial distribution, and feeding behaviour across the plant parts. Field surveys were conducted over three seasons in the agricultural field of Amarkantak, Madhya Pradesh, India. Observations are focused on leaves, flowers, and stems to find visitor preferences for feeding and resting. Besides its invasive nature, P. hysterophorus supported a diverse collection of insect visitors, including generalist pollinators such as bees, butterflies, and beetles etc. which may contribute to pollination and seed dispersal. Herbivores insects were also compiled most of which being biocontrol agents. These findings disclose the complex ecological relationships between Parthenium weedand their insect visitors, and highlight the management strategies should consider both the conservation of biodiversity along with successful control of weeds. This research contributes to our knowledge of the ecology of invasive speciesand their role within insect communities.

A Review on the Ecology of the Noxious Weed Parthenium hysterophorus

This study investigates the metabolomic profile of the Parthenium beetle, Zygogramma bicolorata Pallister (Coleoptera: Chrysomelidae), under thermal stress conditions. This beetle is an effective biological control agent against the invasive and toxic weed Parthenium hysterophorus. Metabolomic analysis identified 1277 metabolites, with significant variation observed among control (27°C), heat stress (35°C), and cold stress (15°C) conditions, highlighting distinct metabolic responses to temperature extremes. Heat exposure yielded the greatest number of unique metabolites, indicating elevated metabolic activity, while cold stress also induced distinct compounds, reflecting specialized adaptive responses. Enrichment analysis revealed consistent upregulation of alkaloids, lipids, and amino acid-related metabolites across all conditions, suggesting their protective roles in membrane stability, cellular signaling, and stress mitigation. Pathway analysis showed that lipid metabolism (glycerophospholipids and sphingolipids) and amino acid pathways (tryptophan, phenylalanine, and histidine) were universally affected, likely reflecting adaptive membrane remodeling and stress-response mechanisms that support beetle survival under fluctuating thermal conditions. Control beetles primarily utilized glutathione and carbohydrate metabolism, whereas heat-stressed beetles exhibited enrichment of nitrogen metabolism and amino acid catabolic pathways. In contrast, cold stress uniquely altered nucleotide metabolism and vitamin B6 pathways, suggesting distinct metabolic strategies in response to temperature extremes. Overall, these findings demonstrate that Parthenium beetles undergo extensive, condition-specific metabolic reprogramming to maintain cellular homeostasis and adapt to thermal stress.

The present study reports the isolation and identification of a γ-proteobacterium which is capable of degrading maneb and its photolytic product ethylene thiourea. The strain SDS18 was isolated from the surface of the most common weed Parthenium hysterophorus growing in agricultural field. Based on molecular systematics the strain SDS18 was identified as Pseudomonas psychrotolerans. Our study first time revealed that a single bacterial strain is capable of metabolising the toxic fungicide maneb and its carcinogenic photolytic product ethylenethiourea. We found that the strain SDS18 can tolerate upto 150ppm of maneb and 200 ppm of ethylene thiourea and ethylene urea as sole carbon sources. The optimum conditions for degradation were in the presence of ammonium sulphate as nitrogen source at 30°C at pH 7.0. Interestingly, the strain SDS18 exhibited activities like phosphate solubilisation, production and assimilation of ammonia, ACC deaminase activity, production of indole acetic acid and siderophores which are plant growth promoting activities and antifungal activities for Alternaria citri and Cladosporium cladosporioides indicating it could be beneficial for plant growth and maturation. The isolated strain can be used for bioremediation of maneb and its photolytic products.

Iron oxide nanoparticles (IONPs) were biosynthesized via a green co-precipitation method using aqueous extract of the invasive weed Parthenium hysterophorus, yielding particles with an average diameter of 14.65 ± 5.7nm, as confirmed by TEM analysis. XRD revealed a pure crystalline phase with peaks at 2θ = 21.7°, 35.1°, 42.3°, 52.9°, 61.7°, and 69.3°, while SEM-EDS indicated a spherical morphology with 32.62% Fe and 34.97% O composition. DLS demonstrated a uniform distribution, and the zeta potential indicated stability. The IONPs exhibited potent antibacterial activity against Klebsiella pneumoniae, with an MIC of 1.56µg/mL and an MBC of 6.25µg/mL, resulting in inhibition zones of 3.4mm (6.25µg/mL) and 6.8mm (12.5µg/mL). However, they showed no activity against Staphylococcus aureus. Antifungal assays revealed significant inhibition of Fusarium sp. growth on Czapek-Dox agar after 4 days at 28°C. In hydroponic plant growth studies, 20mg/L IONPs enhanced Arachis hypogaea biomass by 20% (plant length), 15% (primary root length), and 25% (chlorophyll content), and Brassica juncea by 18% (primary root length), 22% (chlorophyll content), and 28% (fresh weight) over 14 days. Anti-hemolysis assays on human RBCs showed concentration-dependent protection with an IC50 of 600µg/mL (hemolysis 14.37-37.6% at 600-1400µg/mL). Photocatalytic degradation of Reactive Black 5 dye (10 - 5M) achieved 99.57% efficiency in 60min under sunlight (6.08 kWh m-2 intensity), following pseudo-first-order kinetics (k = 0.065min⁻¹, R² = 0.997), with hydroxyl radicals identified as the primary reactive species via scavenging experiments (efficiency drop to 32.17% with IPA). Total organic carbon (TOC) analysis confirmed mineralization, as evidenced by a reduction in carbon content over time. This circular economy, also known as the waste-to-wealth approach, transforms invasive P. hysterophorus waste into IONPs for antimicrobial, agricultural, biomedical, and wastewater remediation applications.

The construction industry in South Asia, heavily reliant on coal-fired brick kilns, significantly contributes to environmental pollution, impacting public health and agricultural productivity. In Pakistan, brick kilns consume over 50% of the nation’s coal, often using low-quality coal and waste materials that emit harmful pollutants such as CO, SO2, particulate matter (PM), and hydrogen fluoride (HF). This study explores sustainable brick production by incorporating agricultural by-products, specifically the invasive weed Parthenium hysterophorus L., as an additive to clay. The integration of 15–20% Parthenium biomass by weight resulted in bricks with enhanced porosity (up to 64% at 50% biomass addition) and reduced density, lowering energy consumption during firing by approximately 15–20% while maintaining compressive strength within acceptable limits (15–20 MPa). Additionally, this approach reduced HF emissions by over 50% during the firing process, mitigating adverse effects on nearby vegetation. Conversations with 50 brick kiln owners in Peshawar revealed enthusiasm for adopting this method, contingent on cost reductions (potentially 10–15% lower production costs) and government-supported pilot projects. This research aligns with UN Sustainable Development Goals (SDGs) for sustainable cities (SDG 11), responsible consumption (SDG 12), and climate action (SDG 13), promoting a circular green economy. Policy interventions, including subsidies, training workshops, and awareness campaigns, are recommended to facilitate adoption, benefiting local communities and the environment. Future studies should investigate the scalability and adaptability of this approach across diverse regions and manufacturing sectors.

The potential of plant allelochemicals to control Parthenium hysterophorus weed

The feeding potential and non-feeding potential of Mexican beetle, Zygogramma bicolorata Pallister, 1953 (Coleoptera, Chrysomelidae) were studied on a common weed Parthenium hysterophorus, under laboratory conditions (temperature 25 to 30 0C and RH 60 to 65%). Ten different sites were chosen from the Dehradun district considering the widespread availability of Parthenium weed in the region. It was observed that the feeding potential of the adult was highest in site 7 (Prem nagar). The feeding rates at the site 7 were, 0±0.00 at 0 hours, 1.8±0.11 at 24 hours, 2.77±0.14 at 48 hours, 3.87±0.03 at 72 hours, 2.74±0.11 at 96 hours, 2.6±0.05 at 120 hours, 0±0.00 at 144 hours and at 2.67±0.07 at 168 hours. Z. bicolorata was more active when it was used in higher density and at initial growing stages of the weed. The fully matured adult stages of Z. bicolorata were less potential in comparison to the younger ones. Non-feeding potential was tested on different weeds and grasses indicated that the beetles were exclusive feeders of Parthenium weed and contributes towards achieving the goal of sustainable development.

The weed Parthenium hysterophorus is an invasive, ubiquitous and significantly threatens agricultural productivity and biodiversity. This study explored the potential of allelopathy for its impact by investigating the effects of aqueous extracts from 31 plant species on seed germination of parthenium. The study revealed that all the 31 plant species adversely affected the germination of Parthenium seed. Leaf extract of Azadirachta indica, Cassia tora, Mentha arvensis, and Xanthium strumarium caused 100% inhibition of seed germination within7 days and did not allow further seed germination. Inhibitory effect of some plant species were persistent on germination of parthenium seed upto 15 days. Minimum inhibition in seed germination was recorded in extract of Achyranthes aspera i.e. 24.13%.

Abstract Background Herbicides are commonly used to safeguard crops against weed damage, but their effects on non-target organisms like Zygogramma bicolorata, a natural bio-control agent feeding on Parthenium hysterophorus, an invasive weed, have raised concerns. This study investigates the impact of pendimethalin, a widely used herbicide, on Z. bicolorata. Results The results of the present study reveal adverse effects induced by pendimethalin on various life parameters of Z. bicolorata. Fecundity decreased by approximately 20.98%, while egg viability reduced by about 18.36%. Female lifespan decreased by approximately 11.18%, and male lifespan decreased by about 13.80%, with an associated increase in developmental time period. Oviposition days after pendimethalin treatment showed only a minor 9.18% decrease compared to the control group. Pendimethalin also negatively impacted the gut antioxidants of Z. bicolorata, resulting in oxidative stress that can harm gut health and disrupt biological processes. At the molecular level, it has also been observed the DNA damage in the midgut tissue of Z. bicolorata. Conclusion This study underscores the unintended consequences of herbicide use on non-target organisms, emphasizing the potential threats to biodiversity. Evaluating chemical impacts on non-target organisms is crucial for ensuring responsible and sustainable chemical use in agriculture and other sectors.

Parthenium hysterophorus invasive weed valorization into biochar for removal of pharmaceuticals and personal care products: Competitive adsorption analysis via batch and fixed–bed column systems

Invasive weed Parthenium hysterophorus has been wreaking havoc all over the terrestrial ecosystems in tropics and sub-tropics. The traits governing successive invasion and colonization of this weed are superficial seed production ability, inedibility to animals and allelopathy. Allelopathy refers to the impact of plants on nearby plants or their associated microflora or macrofauna by the production and release of allelochemicals. The identification and characterization of allelochemicals will be helpful for utilizing in agricultural pest management operations. In this rationale, a preliminary probe has been made to assess the potential of Parthenium hysterophorus aqueous extracts as a farmer friendly herbicide. Raddish seeds have been used to test the phytotoxicity of the extracts and complete germination inhibition was found with application of 25% extract. Seeds in control has a germination speed of 5.29 seeds germinated/day and produced robust seedlings with 4.81 cm shoot and 2.87 cm, whereas application of 20% aqueous extracts has reduced the germination speed to 0.17 seeds germinated/day with nil seedling formation. On working out phytotoxicity percentage, it is revealed that 10% extract application has produced 100% phytotoxicity. Interestingly, the phytochemical analysis of the Parthenium hysterophorus aqueous extracts by GC-MS has revealed the presence of 4 phytotoxins viz., 1-Tetradecene, 2-methyldodecane, Eicosane and 1-Decanol, 2-hexyl-.

Co-application of Parthenium biochar and urea effectively mitigate cadmium toxicity during wheat growth

Invasive alien plants (IAPs) present a severe threat to native ecosystems and biodiversity. Comprehending the potential distribution patterns of these plant invaders and their responses to climate change is essential. Parthenium hysterophorus, native to the Americas, has become an aggressively invasive species since its introduction to China in the 1930s. This study aims to collect and reconstruct the historical occurrence and invasion of P. hysterophorus. Using the optimal MaxEnt model, the potential geographical distributions of P. hysterophorus were predicted based on screened species occurrences and environmental variables under the current and three future scenarios in the 2030s, 2050s, and 2070s (i.e., SSP1-2.6, SSP2-4.5, and SSP5-8.5), and the invasion risk of P. hysterophorus in Chinese cities, croplands, forests, and grasslands was assessed. The results show that: (1) The species initially invaded highly suitable areas and further spread to regions with non-analogous climate conditions. (2) Under the current climatic conditions, the overall potential distribution of P. hysterophorus is characterized by more in the southeast and less in the northwest. Climate variables, including mean annual temperature (bio1), precipitation in the wettest month (bio13), isothermality (bio3), and temperature seasonality (bio4), are the primary factors influencing its distribution. (3) The potential distribution of P. hysterophorus will expand further under future climate scenarios, particularly toward higher latitudes. (4) Forests and crop lands are the areas with the most serious potential invasion risk of P. hysterophorus. Therefore, we suggest that the government should strengthen the monitoring and management of P. hysterophorus to prevent its spread and protect agro-ecosystems and human habitats. Depending on the potential risk areas, measures such as quarantine, removal, and publicity should be taken to mitigate the threat of P. hysterophorus invasion and to raise awareness of P. hysterophorus invasion prevention.

Oviposition biology and seed damage by Smicronyx lutulentus Dietz (Coleoptera: Curculionidae), a biological control agent of Parthenium hysterophorus L. (Asteraceae) in South Africa

Puccinia abrupta var. partheniicola, the so-called winter rust of parthenium weed (Parthenium hysterophorus), an invasive alien weed in India, was rediscovered at an epiphytotic scale in February 2023 following a prolonged period of presumed absence in the field. Disease incidence was 80–90% in large tracts of P. hysterophorus stands along the roadsides in an area of 5 km2 near Attibele–Sarjapura road (948A) in Anekal taluk of Bengaluru Urban district in Karnataka. Pycnial, aecial or telial stages of the rust were not found. The morphological parameters of uredinia and urediniospores completely matched those originally described, thus confirming the fungal identity. The significance of this rust epiphytotic to P. hysterophorus biocontrol in India is discussed together with the planned follow-up activities.

Valorization of Parthenium hysterophorus weed into biochar for adsorptive removal of industrial dyes from multi-pollutant aqueous systems

The Asteraceae family of plants, which has 16,000-17,000 genera and 24,000-30000 species, is diverse and widely spread, notably in the tropics and subtropics. Asteraceae has capitula head bracket traits that are unique to this genus of plants. This study's goal was to identify the micro-morphological makeup of the trichomes in Parthenium hysterophorus L. Invasive weed Parthenium hysterophorus L. is erect, short-lived fast-growing plant is found in hot areas and is known for its luxuriant growth. As the stem attains maturity, becomes harder. Mature stems are greenish and coated in tiny, soft hairs called hirustles. Later leaves are simple and deeply pinnatifid, while early leaves create a rosette habitat. Hundreds of tiny flower heads, or capitulum, are arranged in clusters at the apex of the branches. Trichomes are epidermal appendages that are frequently seen on the leaves, stems, and fruits of plants. There are two types of trichomes: glandular and non-glandular. The immature leaves and stem of Parthenium hysterophorus L. were cut into slices, the layers were removed, and the specimen was examined at X4, X10, X40, and X100 magnifications under light microscope. The sample was taken from the stem, which was located one to three centimeters from the tip. 14 different types of trichomes, including cylindrical, moniliform, simple uniseriate, non-glandular sessile, and palate types of glandular trichomes, are observed on the leaves, petiole, and stem of Parthenium hysterophorus L. These trichomes are primarily identified based on their structural differences. Trichomes are an important taxonomic tool for differentiating between species and genera. In respect to aridity, the study presents several new features that give future taxonomists a basic understanding of trichome diversity.

Techno-economic, energy, and exergy analyses of invasive weed gasification for hydrogen enriched producer gas production