Climate change is accelerating ecological transformations in freshwater systems, profoundly influencing the growth, distribution, and ecological impact of invasive aquatic weeds. Rising temperatures, altered precipitation patterns, and elevated CO2 levels are expanding the range and competitiveness of species such as kariba weed, Salvinia molesta D.S. Mitch (Salviniaceae), and water hyacinth, Pontederia crassipes von Martius (Pontederiaceae), etc., often at the expense of native flora and fauna, thus reshaping aquatic ecosystems. This narrative review examines how these environmental shifts not only favour weed proliferation but also compromise the performance of biological control agents by disrupting their life cycles, reducing host plant quality, and increasing environmental stress, which may cause far-reaching implications. It also highlights the importance of integrating ecological forecasting with sustainable interventions to safeguard aquatic biodiversity under changing climate regimes. The review underscores the need for climate-adaptive management strategies and targeted bioagent deployment, particularly in underutilized regions like India.

Alligator weed (Alternanthera philoxeroides), originally from South America, is a notorious semi-aquatic invasive species in many countries, including India. Due to its amphibious nature, it not only damages the aquatic environment but is also detrimental to the terrestrial ecosystem. To seek an environmentally sound control option for alligator weed, this study focused on selecting an appropriate mycoherbicidal agent. A series of steps from field survey-based collection, isolation and selection of promising fungal strains, followed by host range determination to biocontrol potential studies against the weed were undertaken. Twenty-three phytopathogenic fungi were isolated, and among these, the fungi with the highest herbicidal activity (> 90% disease severity) were subjected to morphological and molecular characterisation and identified as Alternaria alternantherae (= Nimbya alternanthera). The fungus and its crude metabolites were tested against 76 plant species, showing a relatively narrow host range. This fungal species is being reported from West Bengal, India, for the first time. Although the fungus has been considered as a potential biocontrol tool against alligator weed in countries such as Australia, Brazil and China, long-term, detailed research for A. alternantherae and its active metabolites to be developed as bioherbicides against alligator weed remains indispensable.

Abstract Invasive weeds are rapidly adapting to evolutionary changes, brought about by exposure to the plethora of plant-antagonist’s interactions, which eventually leave an effect on the biological control of the weed. These interactions create an array of biochemical responses in the plant, which induce a range of defensive mechanisms to reduce the threat of injury. The present investigation reports the role of plant secondary metabolites in plant defense that may involve deterrence of antifeedant activity associated with the application of biocontrol agents against Pontederia crassipes. Generally, an infestation is preferred on non-challenged plants, as increased content of alkaloid, phenol, or tannin, which Pontederia crassipes produces when infested by its agents, deters the latter by providing a toxic unpleasant atmosphere. Variation in flavonoid level also brings about some physiochemical changes in the weed which impede the entry of phytopathogens. When a few metabolites are used to dissuade the agents, some, like glycosides, attract feeders to lay eggs and allow their population to flourish. This study concentrates on the signals that enable P. crassipes to recognize and respond to the attack and measure the effect in biochemical terms. Through this has, an overall outlook of the fitness costs of attack not only for the weed but over the range of trophic levels has been enlightened with more scope to understand the underlying mechanisms, before the multi-agent release of agents.

The field experiment was carried out at Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India, during the Kharif season of 2018 to study the efficacy of pre- and post-emergence herbicides on suppressing weed flora and nutrients uptake by weed and blackgram (Phaseolus mungo) crop. The experiment was laid out with eleven treatments in a randomised complete block design with three replications. Nine weed species (one sedges, two grassy and six broad-leaved) belonging to eight families were found dominant in blackgram. Among the major sedges observed in the experimental plot, Cyperus rotundus (Cyperaceae) was the most dominant and aggressive weed. Some grass weeds were Echinochola colona (Poaceae) and Cynodon dactylon (Cyperaceae) whereas broad-leaved included Phyllanthus niruri ((Phyllanthaceae), Solanum nigrum ((Solanaceae), Trianthema portulacastrum (Aizoaceae), Cucumis melo (Cucurbitaceae), Cleome gynandra (Capparaceae) and Mimosa pudica (Fabaceae). A significant reduction in weed flora was observed in weed free plot, further among the herbicidal treatments’ pre-emergence application of pendimethalin 30 EC 75 kg/ha followed by imazethapyr 0.060 kg/ha as post-emergence reduced the weed flora at 15, 30, 45 and 60 Days after sowing respectively. The lowest nutrient depletion by weed, highest seed yield (925 kg/ha), net return (? 48549/ha), B: C ratio (2.65) and nutrient uptake by blackgram were recorded with pre-emergence pendimethalin 30 EC 0.75 kg/ha followed by imazethapyr 0.060 kg/ha as post-emergence.

Phenols are major compounds produced by plant species as a peripheral stimulus or as a regulatory defense mechanism under different environmental biotic stresses. These secondary metabolites are generated from shikimic and acetic acid metabolic pathways. The aromatic benzene ring compound plays an important role in plant development, especially in the defense forefront. They provide structural integrity and support to the plants. Phenolic phytoalexins released by pathogen/arthropod-attacked or wounded plants nullify or repel organisms for the advantage of the host. The allelopathic potential of phenolic compounds is observed in both natural and managed ecosystems. The global impacts of climatic variabilities such as drought, increased carbon dioxide, or greenhouse gas emissions alter the quantitative response of plant phenols. This review primarily discusses the different aspects of phenolic interactions concerning health, antioxidant properties, and insect-plant interaction as a nexus of soil and plant relations in response to variable climatic conditions.

The contest between conspecific males for mating opportunities is common among different species. Many species of butterfly defend a territory for the purpose of mating. In our study, the mating and courtship behaviour of the Indian common crow butterfly Euploea core core (Lepidoptera: Nymphalidae) was observed, which is a widely distributed native and important pollinator. Indian common crow butterfly defends a sunspot as territory for mating. When other butterflies come near or into the territory, a non-contact aerial interaction occurs between them. The owner of the territory excludes the intruders by chasing them out. Males of this butterfly species prefer a territory characterized by sunlight at the edge of woodland or open tracks in the forest containing host plants and oviposition sites near it. Indian common crow butterfly exhibits territorial activity throughout the day but is more frequent in the afternoon. The frequency of chasing for a longer duration is very low. The duration of chasing for the conspecific male is higher than that of heterospecific males. This is the first documentation about the territorial and courtship behaviour of Indian common crow butterflies. A new distribution record for the species has been reported as well. Such studies are essential not only to understand their behavioural patterns but also to understand their needs while planning conservation efforts.

The invasive macrophyte water hyacinth, Pontederia crassipes (Mart.) Solms (Pontederiaceae), was first introduced in India at the Acharya Jagadish Chandra Bose Indian Botanic Garden, near Kolkata in 1889 from where they spread throughout the sub-continent. An extensive systematic survey of water bodies in and around Kolkata, India, was done for the first time to assess the natural occurrence of indigenous phytopathogenic fungi of the weed between 2014 and 2019. The study brings into light several species, along with some first reports, of naturally occurring native phytopathogenic fungi and their evolutionary-related lineages. The occurrence and frequency of pathogens varied from site to site. Around 150 fungal pathogens isolated from water hyacinth were evaluated for their disease-causing potential against the weed. The isolated fungi were identified using morphological and molecular techniques. Fusarium Link followed by Alternaria Nees were the highest and most consistently isolated genera. Seven potential fungi that caused more than 90% disease in whole plant pathogenicity bioassay were subjected to host-range evaluation against 67 plant species selected based on ecological nearness or economic significance. Among these Fusarium oxysporum f. sp. lycopersici (WHK-59) was found to have a narrow host range and be effective against water hyacinth. With further studies on their impact assessment, environmental viability and tolerance, few of them, especially F. oxysporum (WHK- 26, 106) may effectively reduce population growth of water hyacinth by themselves or in conjunction with other introduced biocontrol agents, including insects and other plant pathogens.

Climate change and rapid habitat degradation have led to a rapid decline in the population of snakes. Hence constant monitoring of their diversity and wellbeing is necessary. During the present study under our Sarpa Sathi project, we surveyed for snake diversity using time-constrained search, incidental encounters in and around the Mysore city, Karnataka, India, for the first time. During the study period of three years, we have identified 24 species of snakes, belongs to 7 families, among which 18 are non-venomous, 2 mild venomous and 4 are venomous. The study indicate a decent diversity of snakes in the region and highlight on the need for increased efforts towards conservation of these important members of food web.

Diversity and abundance of herpetofauna are an integral part of a healthy ecological food web and indicators of environmental changes. Hence a study was conducted in Dantan I, Paschim Medinipur, West Bengal, India, from January 2020 to January 2021, to determine the diversity and prepare a checklist of herpetofauna in this area. There is hardly any comprehensive work on herpetofauna in this region. The present study provides baseline information about herpetofauna diversity in this area. A total 34 species of Herpetofauna were observed. These included 23 species of reptiles from 2 order (Squamata and Testudineus) and 8 families, represented by 14 snakes species (4 venomous and 10 non-venomous), 1 turtle and 8 lizards. Amphibians w11 species represented amphibians (Anura), 5 families have been included in this first-ever comprehensive checklist from the area. Such studies are essential from time to time to monitor the increasing impact of anthropogenic global environmental changes and frame policies accordingly to safeguard these precious organisms and prevent biodiversity degradation.

Global agricultural demand and the impact of fluctuating climatic conditions including global warming have catastrophically limited crop productivity and immensely outstretched the market value of agricultural products leading to acute inflation. The effect of desiccation or drought stress in plants is manifested at three levels viz. morphological, biochemical, and molecular and plants possess their own molecular and signaling arsenal to combat or ameliorate various stresses. For decades, stress-tolerant cultivars have been investigated and modulation of polyamine (PA) signaling was found to play a major role in attenuating environmental stresses including drought as major abiotic stress. PA metabolism pathways with their ability to crosstalk with both primary and secondary metabolic pathways have been correlated with several other responses such as seed germination, plant growth, development, defense, hormonal regulation, stress tolerance, and crop yield. Recent transcriptomic and metabolomic approaches have expanded the knowledge on the regulation of stress-induced biochemical, molecular, and physiological alterations. To fully comprehend the intricate biochemical network of plant stress physiology, it is necessary to identify exact responses against specific stress stimuli, interpret concurrent epigenetic alterations, and use molecular switching. The present review encompasses recent updates on drought tolerance mechanisms mediated by diverse polyamines playing significant roles in metabolic regulation, oxidative stress management, and systematic stress-reversal signaling. Besides, the drought stress-reversal role of polyamines and their cross-talks with other signaling molecules have also been documented. Gene, enzyme, and transcription factor (TF) functional features were retrieved from the published papers involving transgenic or mutant plants with over-expression or loss-of-function investigations.

Weeds have been recognized as a major biotic constraint towards achieving higher crop productivity as well as quality. With the current crop protection measures, weeds cause nearly one-third of the crop losses among all the crop pests. The effective approach to combat the weed menace is the need-based use of herbicides. Because of widespread growing concern over the environmental aspects of commonly used herbicides as well as their untimely availability, development of weed resistance, etc., the need for the use of conveniently available and biodegradable herbicides is very much imperative. Researchers currently search for novel alternatives to the synthetic herbicides, which would be biodegradable and environment-friendly. Common plants and their metabolites become a source of compounds that can be utilized directly as natural herbicides or as lead structures for the herbicide discovery. These herbal herbicides in judicious combination with other weed management methods would be a potential tool to combat weed menace, especially by the smallholder farmers in rural areas in general, and organic or natural farming in particular.

Human exposure to radiation has expanded considerably in recent years, due to a wide range of medical, agricultural, and industrial applications. Despite its beneficial utilities, radiation is also known to have a deleterious effect on cells and tissues, largely through the creation of free radicals, which cause severe damage to biological systems through processes such as DNA double/single-strand fragmentation, protein modification, and upregulation of lipid peroxidation pathways. In addition, radiation damages genetic material while inducing hereditary genotoxicity. Developing measures to counter radiation-induced damage is thus considered to be of significant importance. Considering the inherent capability of plants to survive radiative conditions, certain plants and natural compounds have been the subject of investigations to explore and harness their natural radioprotective abilities. Podophyllum hexandrum, an Indian medicinal plant with several known traditional phytotherapeutic uses, is considered in particular to be of immense therapeutic importance. Recent studies have been conducted to validate its radioprotective potential alongside discovering its protective mechanisms following γ-radiation-induced mortality and disorder in both mice and human cells. These findings show that Podophyllum and its constituents/natural compounds protect the lungs, gastrointestinal tissues, hemopoietic system, and testis by inducing DNA repair pathways, apoptosis inhibition, free radical scavenging, metal chelation, anti-oxidation and anti-inflammatory mechanisms. In this review, we have provided an updated, comprehensive summary of ionizing radiations and their impacts on biological systems, highlighting the mechanistic and radioprotective role of natural compounds from Podophyllum hexandrum.

Monitoring of regional species diversity enables estimation of the health of an ecosystem and the functional role of each species. It can be a useful tool to frame recommendations to reduce human mediated environmental degradation. Recently we have been monitoring and recusing snake species from various urban-rural gradient ecosystems using citizen science programmes. The present paper reports a new distribution record and rescue of Glossy Belied Racer, Platyceps ventromaculatus (Gray, 1834) from a human habituation in Phalodi, Jodhpur, Rajasthan, India. Such reports helps supplement the necessary information on conservation management of habitat and the biodiversity as a whole.

A snake rescue project, named Sarpa Sathi, has been running around Jawai dam area, Rajasthan, India since 2019, where during a rescue operation of snake, we sighted and recorded the rare Leith’s Sand Snake (Psammophis leithii). Previous documentation of this particular species has been reported from other parts of Rajasthan but proper photographic evidence with identification of the same has been possible for the first time.

From ancient history, complementary and alternative medicines have played a significant role as holistic therapeutic treatments of various human diseases including cancer, diabetes, neurological diseases, and skin problems. One Indian medicinal plant (herb), Bacopa monnieri has been used in many parts of the world as such medicine, particularly for the treatment of various neurological disorders. It is well known as a potent “tonic for the human brain,” which serves as a memory enhancer. Multiple studies proved that this herb contains a plethora of potential bioactive, phytochemical compounds with synergistic properties. The main purpose of the present review is to shed light on the use of Bacopa monnieri and its active principles (bacosides) in the management of neurological disorders. Furthermore, the signaling pathways modulated by bacosides have been critically discussed in this review. Moreover, we have critically summarized the present knowledge of this perennial creeping herb based upon the literature mining from different scientific engines.

Invasive plant species are a major threat to biodiversity and agricultural productivity. Hence, efforts to manage these menace involves extensive and effective use of chemical herbicides amongst others. However, not only is the impact of control with chemical herbicides short-lived but also leads to negative impact on human health and environment due to non-target herbicide-drift and runoff from the sprayed areas. This has ushed in much-anticipated nature-based potential regulators of weed species, in an attempt to lower the utilisation of chemical herbicides. Mycoherbicides have been seen as a benign, eco-friendly, host-specific, and replacement for chemical herbicides. There are several noteworthy genera of fungus that have been proved to be effective against weeds. They either produce strong phytotoxins or are often used as spore/conidia-based solutions and applied as a spray in growth media. One of such potential genera is Colletotrichum Corda 1831. Compared to other potent fungal genera, with well-established roles in conferring herbicidal activities by producing competent phytotoxins, only a few species under genus Colletotrichum are known to produce fungal metabolites be used as phytotoxins. This article elucidates the current understanding of using spore suspension/phytotoxin of Colletotrichum as a weedicide. We also discuss the interaction between fungal metabolites release and Colletotrichum-target plant, from a molecular and biochemical point of view. This review article has been written to accentuate on the potency of Colletotrichum, and to serve as an eye-opener to consider this genus for further fruitful investigations. However, inconsistency associated with mycoherbicides in terms of viability and efficacy under field conditions, production of bioactive compound, slow natural dispersal ability, etc., have often reduced their utility. Hence, our study emphasizes on the need to do extensive research in elucidating more phytotoxins from necrotrophic phytopathogenic microorganisms with novel mode of action for field application.

During the COVID-19 lockdown we had more opportunities to observe biodiversity around our homes. On one occasion, Ray observed a common Indian house crow (Corvus splendens) with uncommon white patches on its plumage, quite unlike the characteristic black body and gray neck of most house crows. The white patches distinguished the crow from hundreds of other members of its species thriving in the area. This crow's atypical plumage was due to a congenital genetic condition called leucism, a partial or complete loss of coloration. The incidence of leucism in wild bird populations scarcely exceeds 1%. Observing an abnormally colored bird provides insight into intraspecific phenotypic variability as well as how variations persist in nature. Long-term observations are needed to better understand the ecology of such rare leucistic birds.