Invasive Alien Species Research Articles

Impact Assessment of Invasive Alien Plant Species on Chimdi (Barju) Lake of Eastern Nepal

The present study has been carried out to evaluate the impact assessment of invasive alien plant species on Chimdi Lake using focus group discussion method. Chimdi (Barju) Lake is an important wetland in Eastern Nepal, faces ecological challenges due to the rapid spread of invasive alien plant species. Assessing the impact of these species is essential to understand their effects on the lake's biodiversity and ecosystem services and to develop effective management strategies for the conservation of the lake. The lake was found to be dominated by two aquatic IAPS, Pontederia crassipes followed by Ipomoea carnea. Additionally, eight other terrestrial IAPS (Ageretina adenophora, Chromolaena adorata, Lantana camara, Mikania micrantha, Mimosa pudica, Senna occidentalis., Senna tora, and Xanthium strumarium) were also recorded from the lake. Apart from these, there were several more macrophytes and hydrophytes, such as Nelumbo nucifera, Nymphaea alba, Ipomoea aquatica, etc., which created a thick layer of peat over lake water. These IAPS characteristics encourage growth and cover in water bodies, which block sunlight, change the chemistry of the water, and also reduce the habitat quality of native water animals and plants.

PLANT COMMUNITIES DISTURBED BY INVASIVE SPECIES ON THE PĂPĂDIA ISLAND IN THE DANUBE BASIN

The territory under study is is represented by Papadia Island in the Danube Basin. This island located near the town of Dăbuleni is characterized by a very rich flora and fauna and an extremely valuable biodiversity from a conservation point of view. Invasive species have a negative impact on forest, grassland, and agricultural ecosystems around the world, sometimes associating and forming segetal or ruderal plant communities. Exotic species compete with native species and threaten ecosystem stability. The studies on alien species are of particular interest today to protect natural habitats and reduce or eliminate ecological and economic damage. Invasive species are one of the most serious threats to biodiversity. The paper presents the results obtained from the studies carried out regarding the plant communities whose structure is disturbed by the increase in the number of invasive species, as well as their density on the Păpădia Island in the Danube basin. In this region, the intensive abiotic activity, but not only that, has brought about the invasion of allochtone (invasive alien) species plants in the natural and semi-natural degraded ecosystems, especially in alluvial forest habitats. The species has been found in the following în mai multe types de comunități vegetale.

Forewarned Is Forearmed: Documentation on the Invasion Risk of Asclepias speciosa in Greece and Europe

Biological invasions threaten biodiversity and agroecosystems, and early warning systems can minimise the spread of invasive alien species with limited resources. This study documents the presence of the alien plant Asclepias speciosa Torr., native to North America, that was first discovered in 2022 on Mount Vrontou, Central Macedonia, Northern Greece. This is the second European record of this alien species, after Lithuania, confirming its adaptability to contrasting European biogeographical regions. To enable future monitoring, this study provided new data on morphological traits of the species (above-ground parts), climatic tolerance (precipitation and temperature regimes), habitats with co-occurring species, pollinators, current reproductive potential, and seed germination at controlled temperatures (10 °C, 15 °C, and 20 °C). The high probability of misidentification with the highly invasive A. syriaca in European inventories supports the theory that A. speciosa may have been present in Europe long before it was officially reported. The lack of an EU-mandated reassessment of A. syriaca monitoring raises concerns regarding the potential invasion risk of A. speciosa in European natural and semi-natural areas or agricultural lands. Inspection mechanisms, early warning systems, and preventive measures are therefore essential to protect local biodiversity and agriculture from potential A. speciosa invasion, a risk that may be exacerbated by climate change.

The “Ants of Cyprus” website: a dynamic, online awareness raising and conservation tool

Ants are an important arthropod group due to their involvement in ecological processes amongst others as ecosystem engineers or predators, but some invasive alien species are also implicated in detrimental environmental, economic and human health effects. Despite recent advancements, the ant biodiversity of Cyprus is still in need of further research with previous online species inventories synthesising a checklist of just 65 native and 10 alien species. The “Ants of Cyprus” website (https://sites.google.com/view/ants-of-cyprus) aims to: (1) raise public awareness and increase local knowledge on the biodiversity and ecological significance of ants, (2) provide ecological data and (3) enhance conservation efforts and management practices for native and alien ant species, respectively. This dynamic, user-friendly website has been designed for use by the scientific community, conservation officers and the wider public and it will be regularly updated as new information and data are generated. Additionally, this information will be critical for reporting on progress towards biodiversity targets and goals.

Pathogens threatening agriculture and biodiversity in South Africa: A horizon scanning approach

There is mounting evidence that invasive alien species (IAS) have adverse effects on plant health and the global economy, posing a significant threat to biodiversity and ecosystem functioning. Identifying and assessing emerging IAS, such as plant pathogens, is a proactive approach that might assist in prioritising potential pathogen threats before they become established or widespread, negatively affecting plant health, crop production, animal production, animal health by affecting pastures and food security in South Africa. We collected information from the CABI Invasive Species Compendium and Crop Protection Compendium on plant pathogens that are present in neighbouring countries and are likely to be introduced throughout the Republic of South Africa using an expert-elicitation horizon scanning study. Pathogens with the highest score were determined based on their strong capability on the chance of entry, establishment, economic impact, and biodiversity destruction. The current study revealed that only 17 pathogens (6 fungi, 7 viruses, 2 bacteria and 2 phytoplasma) had been prioritised due to their potential to enter the country and have been reported in the neighbouring countries. Maize lethal necrosis disease, Candidatus Liberibacter asiaticus, Candidatus Phytoplasma palmae, Fusarium oxysporum f.sp. cubense tropical race 4, and Maize chlorotic mottle virus have the highest potential to enter and establish in the country. The most effective phytosanitary actions for the high scoring pathogen were to conduct surveillance for their potential presence in South Africa and risk analysis, especially for organisms recorded in neighbouring countries.

Land Use/Change and Local Population Movements in Stone Pine Forests: A Case Study of Western Türkiye

One of the important distribution areas of stone pine (Pinus pinea L.), a native tree species of the Mediterranean Basin in Türkiye, is the Kozak Basin. Pine nut production plays an important role in the livelihood of the rural people of the Kozak Basin. However, in recent years, as a result of mining activities, climate change, and damage caused by the alien invasive species, the western conifer seed bug (Leptoglossus occidentalis Heidemann 1910 (Hemiptera; Coreidae), the decrease in cone and seed yield in the basin has reached significant dimensions. This process has caused the local people’s income sources to decrease. In this study, land use and land cover (LULC) changes and population changes in the Kozak Basin were discussed during the process, where changing forest land functions, especially economic effects, triggered vulnerable communities due to various factors such as climate change and insect damage. LULC classes of the Kozak Basin and their changes in three time periods are presented using the maximum likelihood method. In addition, the exponential population growth rates of the local people in three different time periods were calculated and these rates were interpolated in the spatial plane with a Kriging analysis. In conclusion, the responses of vulnerable communities to the cone and seed yield decline in the Kozak Basin are manifested by LULC changes and migration from the basin. Therefore, in the management of P. pinea areas, the creation of regulations within the framework of sustainability understanding regardless of ownership difference, stakeholder participatory approach management, close monitoring of ecological events occurring in the basin, awareness of vulnerable communities, and alternative livelihoods can be supported.

Compounds Involved in the Invasive Characteristics of Lantana camara.

Lantana camara L. is native to tropical America and has naturalized in many other tropical, subtropical, and temperate regions in Asia, Africa, Oceania, North and South America, and Europe. L. camara infests diverse habitats with a wide range of climatic factors, and its population increases aggressively as one of the world's 100 worst invasive alien species. Its infestation reduces species diversity and abundance in the natural ecosystems and reduces agricultural production. The life history characteristics of L. camara, such as its high reproductive ability and high adaptive ability to various environmental conditions, may contribute to its ability to infest and increase its population. Possible evidence of the compounds involved in the defense functions of L. camara against natural enemies, such as herbivore mammals and insects, parasitic nematodes, pathogenic fungi and bacteria, and the allelochemicals involved in its allelopathy against neighboring competitive plant species, have accumulated in the literature over three decades. Lantadenes A and B, oleanonic acid, and icterogenin are highly toxic to herbivore mammals, and β-humulene, isoledene, α-copaene thymol, and hexadecanoic acid have high insecticidal activity. β-Caryophyllene and cis-3-hexen-1-ol may function as herbivore-induced plant volatiles which are involved in sending warning signals to undamaged tissues and the next plants of the same species. Farnesol and farnesal may interrupt insect juvenile hormone biosynthesis and cause abnormal metamorphosis of insects. Several triterpenes, such as lantanolic acid, lantoic acid, pomolic acid, camarin, lantacin, camarinin, ursolic acid, and oleanonic acid, have demonstrated nematocidal activity. Lantadene A, β-caryophyllene, germacrene-D, β-curcumene, eicosapentaenoic acid, and loliolide may possess antimicrobial activity. Allelochemicals, such as caffeic acid, ferulic acid, salicylic acid, α-resorcylic acid, p-hydroxybenzoic acid, vanillic acid, unbelliferone, and quercetin, including lantadenes A and B and β-caryophyllene, suppress the germination and growth of neighboring plant species. These compounds may be involved in the defense functions and allelopathy and may contribute to L. camara's ability to infest and to expand its population as an invasive plant species in new habitats. This is the first review to focus on how compounds enhance the invasive characteristics of L. camara.

Defensive Mechanisms of Mikania micrantha Likely Enhance Its Invasiveness as One of the World's Worst Alien Species.

Mikania micrantha Kunth is native to tropical America and has invaded tropical and subtropical Asia and numerous Pacific Islands. It forms dense thickets and reduces native species diversity and populations in its introduced range. This invasive vine also seriously impacts many agricultural crops and is listed as one of the world's 100 worst invasive alien species. Its life history characteristics, such as the production of large numbers of wind-dispersed seeds, vegetative reproduction, rapid growth, and genetic diversity all contribute to its invasiveness. In this review, we focus on how mechanisms to defend against its natural enemies boost the invasiveness of M. micrantha. It possesses potent defenses against natural enemies such as pathogenic fungi, herbivorous insects, and parasitic nematodes, and exhibits allelopathic potential against plant competitors. These defensive abilities, in concert with its formidable life history characteristics, contribute to the invasiveness of M. micrantha, potentially leading to further naturalization. Several other reviews have summarized the biology and management of the species, but ours is the first review to focus on how the defensive mechanisms of M. micrantha likely enhance its invasiveness. Relatively little is known about the array of defensive capabilities of M. micrantha; therefore, there is considerable scope for further research on its chemical defenses.

The wild workforce: Enlisting non-human labor in invasive species management

An all-hands-on-deck rationality appears to characterize invasive alien species (IAS) eradication. Not only are citizens enrolled in their monitoring and management to extend authorities’ capabilities, but a recent trend in so-called nature-based solutions also outsources labor to non-human species. Within the realm of biocontrol initiatives, these non-human actors are strategically enlisted to counter invasive species through various methods such as predation, detection, sensing, niche occupation, and infiltration for internal destruction. This paper critically examines this conscription of non-humans, including sentient animals, to do the dirty work for us, by synthesizing ongoing cases from each of these categories or careers of non-human labor. These range from metabolic and ecological labor, performed with relatively little human intervention, to contrived schemes of capturing, sterilizing, tagging, and releasing Judas animals to locate conspecifics for culling. In the IAS management context, most of this is a kind of necro-labor, where non-human workers, wittingly or unwittingly, end up as assassins, snitches, moles, thieves and destroyers of their targets, the undesired invasives. We argue that wild animal labor has been invisibilized insofar as these non-human laborers either are said to perform their “natural” behaviors or relegated to nature/property themselves, that is, the product of labor. Our paper further helps de-exceptionalize human labor over nature and make visible the kinds of contracts that we are entering into with non-human laborers and hence also our duties and responsibilities. Our focus on labor specifically in invasive species eradication helps highlight the harms involved in the necro-labor that targets undesirable species.

Molecular Data Confirm the Occurrence of the Allochthonous Gambusia holbrooki (Pisces: Poeciliidae) in Sicily and the Maltese Archipelago

A major threat to biodiversity is represented by Invasive Alien Species (IAS), particularly on freshwater ecosystems, which are already heavily altered by human activities. Two of the most pernicious IAS are the eastern and western mosquitofish, i.e., Gambusia holbrooki and G. affinis. These two poeciliids are morphologically very close to each other, and soon after their formal description, G. holbrooki was considered a subspecies of G. affinis. In the following years, several studies proved that these two entities belonged to two different species; nevertheless, it was only at the end of the 1990s that their separate taxonomic status was re-established. In the 1920s and 1930s, both G. holbrooki and G. affinis were asynchronously introduced from the United States into Europe and subsequently translocated globally as biocontrol agents of the malaria vector (i.e., the larvae of the Anopheles mosquitoes), with dramatic consequences for the inland water native fauna. However, due to taxonomic uncertainties and nomenclatural instability, for years, there were doubts about which Gambusia species had been introduced in different regions. The first available molecular studies confirmed the occurrence of G. holbrooki in Europe, but no evidence confirming the occurrence of G. affinis was found. Despite this, some records report the occurrence of western mosquitofish in Italy and Malta. Considering the negative effects that the mosquitofish has on the native biota, it is of paramount importance to know the precise biological diversity of the native and non-native species to better implement environmental management strategies to properly preserve the already-fragile waterbodies. Therefore, to check for the possible occurrence of G. affinis in Italy and Malta, we conducted extensive sampling in Sicily (Italy) and in the Maltese archipelago, aiming to verify the identity of Gambusia populations occurring in the study area. Based on sequences of the mitochondrial cytochrome b gene, we consistently observed the occurrence of only G. holbrooki in the investigated area, finding, almost exclusively, the most common haplotype known for the species in the whole invaded range (i.e., “HOL1”).

Evaluation of Enrichment Approaches for the Study of the Viromes in Mollusk Species.

Invasive alien species such as freshwater snails have significantly affected the food, environment, and the health of humans and animals, which have unfortunately received insufficient attention. To facilitate the study of viromes in snail species, we compared the enrichment effect of cesium chloride (CsCl) and sucrose density gradient ultracentrifugations in the recovery of diverse viruses in Pomacea canaliculata and Achatina fulica. First, we showed that CsCl-based ultracentrifugation enriched more virus contigs and reduced the nucleic acid background of the Pomacea canaliculata and was thus beneficial for virus recovery. Further studies comparing CsCl- and sucrose-based density gradient ultracentrifugations revealed that the former enriched more viral contigs and viral families of RNA viruses, while the latter yielded more DNA viruses from both Pomacea canaliculata and Achatina fulica. Certain RNA virus families, such as Rhabdoviridae, Arenaviridae, Hepeviridae, Astroviridae, and Alphatetraviridae, were exclusively enriched by CsCl-based ultracentrifugation. Conversely, several DNA virus families including Bacilladnaviridae, Nudiviridae, Malacoherpesviridae, and Adintoviridae were solely identified using the sucrose-based method. Therefore, the selection of viral enrichment technique (either CsCl or sucrose density gradient ultracentrifugation) should be carefully considered based on the specific virome (DNA or RNA viruses) being studied in mollusk species.

How to Identify Priority Sites for Invasive Alien Species Policy and Management

ABSTRACTAimIdentifying priority species and introduction pathways has long been a goal of national and international policy for reducing and mitigating the impacts of invasive alien species (IAS). Although identifying priority sites for invasion management is included within Target 6 of the Kunming–Montreal Global Biodiversity Framework, methods for doing so that capture both site sensitivity (i.e., the level of biodiversity value) and susceptibility to invasion have received little attention. Here we describe and implement a data‐driven approach to priority site identification that integrates spatial conservation planning and biodiversity modelling techniques.LocationAustralia.MethodsWe use the modelled distributions of 5113 Australian native species and 12 invasive alien insect species as a case study for demonstrating a data‐driven approach for identifying priority sites for the purposes of IAS surveillance and management. The approach consists of three components, namely the identification of sensitive, susceptible and subsequently their overlap (i.e., priority sites). We also compare our approach with a proposed alternative for use as priority sites, Australia's key biodiversity area (KBA) network.ResultsNumerous sensitive sites were identified across Australia using a large and taxonomically diverse set of native species and areas of known conservation importance. Most IAS distributions had a high degree of overlap with sensitive sites, with 10 out 12 species having median site sensitivities above 0.70. We also demonstrate that, by comparison, using KBA's as priority sites can underestimate the potential threat of environmentally invasive alien insects.Main ConclusionsGiven that sites most susceptible to invasion may not be the most sensitive, implementing site‐based prioritisation approaches should account for both components of priority site identification to guide IAS management and most effectively mitigate their environmental impacts. The approach demonstrated here can be applied at multiple national and sub‐national scales and improve the efficiency of interventions for IAS.

Management Measures and Trends of Biological Invasions in Europe: A Survey-Based Assessment of Local Managers.

Biological invasions are a major threat to biodiversity, ecosystem functioning and nature's contributions to people worldwide. However, the effectiveness of invasive alien species (IAS) management measures and the progress toward achieving biodiversity targets remain uncertain due to limited and nonuniform data availability. Management success is usually assessed at a local level and documented in technical reports, often written in languages other than English, which makes such data notoriously difficult to collect at large geographic scales. Here we present the first European assessment of how managers perceive trends in IAS and the effectiveness of management measures to mitigate biological invasions. We developed a structured questionnaire translated into 18 languages and disseminated it to local and regional managers of IAS in Europe. We received responses from 1928 participants from 41 European countries, including 24 European Union (EU) Member States. Our results reveal substantial efforts in IAS monitoring and control, with invasive plants being the primary focus. Yet, there is a general perception of an increase in the numbers, occupied areas, and impacts of IAS across environment and taxonomic groups, particularly plants, over time. This perceived increase is consistent across both EU and non-EU countries, with respondents from EU countries demonstrating more certainty in their responses. Our results also indicate a lack of data on alien vertebrates and invertebrates, reflecting a need for more targeted monitoring and knowledge sharing between managers and policymakers and between countries. Overall, our study suggests that Europe's current strategies are insufficient to substantially reduce IAS by 2030 and hence to meet the Kunming-Montreal Global Biodiversity Framework target.

Safeguarding Iguana diversity: enabling rapid and low-effort tracking of non-native iguanas through terrestrial eDNA innovations

Reptiles have among the highest extinction risk across terrestrial vertebrates, with habitat fragmentation, habitat destruction, and invasive alien species being the primary causes of reptile species loss on a global scale. Invasive hybridization (i.e. hybridization between native and invasive alien species) is increasing globally, causing the extinction of native genotypes, and this phenomenon is particularly pervasive in Caribbean iguanas. The Lesser Antillean Iguana (Iguana delicatissima), a keystone species of Caribbean coastal ecosystems, has become critically endangered mainly due to ongoing hybridization with the invasive Common Green Iguana (I. iguana). For impactful conservation intervention, the need for early detection of invasive animals and their progeny, or detection of surviving pure native animals, is urgent. We aimed to develop a novel environmental DNA (eDNA) toolkit using Kompetitive Allele Specific PCR (KASP) technology, a method of allele-specific amplification for cost-effective and efficient sampling of terrestrial substrates to aid in mapping the distribution of native I. delicatissima, invasive I. iguana, and signal potential invasive hybridization. We demonstrate proof-of-concept and successfully identified I. delicatissima, I. iguana, and their hybrids via blood samples using our primer sets, as well as successful detection of I. delicatissima in several ex-situ (Rotterdam Zoo) and in-situ (St. Eustatius) eDNA samples, collected with environmental swabs and tape-lifting. We found that sampling potential perching spots yielded the highest number of positive detections via environmental swabbing and tape-lifting. Our toolkit demonstrates the potential of terrestrial eDNA sampling for iguana conservation, enabling faster detection of putative invasive hybridization. Additionally, the method holds promise for other terrestrial cryptic species, contributing to broader collection of population-level information.

The formation, maintenance, and loss of island biodiversity.

Due to the unique geographical features of large numbers, isolated by water and diverse formation histories, islands have become natural laboratories for ecological and evolutionary research. Islands have a high proportion of endemic species and disharmony in representing the species compared with that in the continent, which provides a good opportunity to explore the formation of island biodiversity. In this review, we focuse on island ecosystems and describes the progress of research in island biogeography in recent years from three aspects: formation, maintenance, and loss of island biodiversity. First, we take several representative island systems in the world as examples to introduce the formation mechanism of island biodiversity from species dispersal and immigration, population establishment and selection, species evolution and adaptive radiation. Based on the Equilibrium Theory of Island Biogeography, we then review the species-area relationship and species-isolation relationship and focus on the research progress in community assembly, including Diamond's rule, nestedness pattern, the framework of community structure of island biota, and species interactions on islands. We also discuss the high extinction risks of island species threatened from natural and human disturbances, especially from the impact of habitat loss and change, climate change, alien species invasion and the synergistic effect of these factors on the loss of island biodiversity. Finally, based on the status of island biodiversity, we summarized the current conservation practices for island biodiversity and possible research frontiers in island biogeographic studies.

Common agricultural weeds among alien invasive plants in China: Species lists and their practical managing strategies.

Plant invasion is a big challenge to weed management of agricultural lands. In order to reveal the list of common weed species among alien invasive plants, and reveal practical management strategies, we extracted the species lists of common alien agricultural weeds (CAAWs) of various arable lands and plantations, by comparing the lists of alien invasive plant species and common weed species published in China. Totally 88 species from 18 families were recognized as CAAWs, among which 43.0% are native to North America, followed by South America (34.4%), Europe (29.0%), Asia (23.7%) and Africa (17.2%); 62.4% were introduced into China from 1840 to 1949. CAAWs such as Aegilops tauschii Coss., Alopecurus myosuroides Huds., Lolium multiflorum Lamk, Avena fatua L., Phalaris minor Retz, Phalaris paradoxa L., Veronica persica Poir., Geranium carolinianum L., Ranunculus muricatus L., and Cerastium glomeratum Thuill. frequently infest highlands with summer-ripe crops such as wheat and oilseed rape; Alternanthera spp., Panicum repens L., Paspalum conjugatum Bergius, and Ageratum conyzoides L. frequently infest highlands with autumn-ripe crops; and Paspalum distichum L., Alternanthera philoxeroides, and Ammannia coccinea Rott. occasionally infest rice fields. Troublesome CAAWs in plantations in China mainly consist of tall herbs, and climbing or spiny plants, such as Mikania micrantha Kunth, Ipomoea spp., Solidago canadensis L., Erigeron spp. and Bidens spp. Management strategies against CAAWs in current China mainly rely on chemical control, tillage, soil mulching, and manual removing of weeds. Next, effective risk assessing models targeting to different sorts of arable lands or plantations are urgently needed; as well, effective, feasible and sustainable integrated management strategies against troublesome CAAWs should be developed and applied.

Building Capacity of Conservation Area Stakeholders in Managing Invasive Species

One of the ecological challenges in managing conservation areas is the colonization and establishment of alien and/or native plant species, especially after forest disturbances. The capacity stakeholders to determine the invasiveness risk of these plant species groups and then management strategies to monitor changes in vegetation structure and species composition is critical. The community engagement program aims to improve the capacity of conservation area stakeholders to identify plant species, including invasive species, and assess the risk of invasive species. Focus group discussion (FGD) were conducted online and offline and targeted stakeholders of the Natural Resources Conservation Agency (Balai Konservasi Sumber Daya Alam–BKSDA) of Central Java Province. Three FGD sessions were held on the topics: (1) forest monitoring and invasion ecology, (2) plant species identification and invasive species monitoring techniques, and (3) vegetation and invasiveness risk analysis. During the discussion, target groups shared ideas and lessons learned related to managing invasive species in the field. The results showed a significant increase in the capacity of the target group (p=4.546e-09), as the average pre-test score was 56.25 ± 13.68 compared to the average post-test score of 75.70 ± 20.27. The target group understands the definition of an invasive (alien) species, the factors that determine the success of this species invasion, and the positive and negative contributions alien species to the newly established ecosystem. Some gaps that need to be addressed relate to methods and criteria for identifying species invasiveness in invasive species risk analysis. As a follow-up, a practical training on invasive (alien) species risk analysis was conducted at different occasion and funding sources.

Perception of local stakeholder groups about certain invasive alien bee pasture species around Lake Kolon

The apiculture sector in Hungary is currently heavily dependent on invasive alien bee pasture species such as the black locust (Robinia pseudoacacia L.), the common milkweed (Asclepias syriaca L.) and the invasive goldenrod species (Solidago gigantea Ait. and Solidago canadensis L.). Between March and October 2023, semi-structured interviews were conducted around Lake Kolon with representatives of the main stakeholder groups: nature conservationists, beekeepers, foresters and farmers. The main aim of our investigation was to assess the perception of the four stakeholder groups about the invasive alien bee pasture species and reveal the conflicting points. Based on our results the presence of black locusts in the area is only undesirable for the conservation sector, the common milkweed is the most damaging species from both a conservational and agricultural point of view. The invasive goldenrod species are less common but are also unfavourable from a conservation point of you. They play a role in preparing bees for winter Beekeepers mentioned other valuable bee pastures (e.g. protective forest strips, flowering trees and shrubs, wildflower meadows, and native bee pastures such as linden) and some of them could replace the invasive alien species. Agricultural subsidies are essential for local farmers. However, they are reluctant to take advantage of subsidies specifically targeted at indigenous bee pasture species, because for some reason they are not seen as favourable. In terms of conflicts, foresters and farmers consider the regulations and restrictions of the conservation sector too strict. Due to the rich wild bee fauna in the area, the conservationists do not prefer the presence of migratory beekeepers with their hives, which puts extreme competitive pressure on wild bees. Beekeepers have reported conflict cases with farmers about bee poisoning in oilseed rape. Overall, it can be said that the beekeepers interviewed are open to the indigenous bee pasture plant species, but currently, they are dependent on the invasive alien bee pasture species. In addition, there are conflict cases between the stakeholder groups, but most of them can be resolved through discussion.

Plant diversity, conservation worthiness and people’s perception in future management of Purbachal Sal Forest, Bangladesh

The Purbachal Sal Forest, a vital ecosystem in the outskirts of Dhaka city facing biodiversity decline, was assessed for its plant composition and public perception of its management and conservation. A total of 190 species under 61 families have been recorded from the study area following the random quadrat method. Analyses showed that among the 190 species, the most abundant tree and shrub in the forest are Shorea robusta Roxb. ex Gaertn. and Melastoma malabathricum L., respectively. In case of dominance based on the Importance Value Index, Shorea robusta is the most dominant tree, followed by Melastoma malabathricum as the most dominant shrub. The percentages of native and exotic species were found to be 75% and 25%, respectively. The Shannon-Wiener Diversity Index in the study area was 0.61, whereas Simpson’s and Margalef’s Indices were 0.178 and 4.77, respectively. From interviews with visitors and stakeholders, this study revealed that the majority of them responded negatively about the presence of exotic species in the forest, and on the other hand, they responded positively on the question of incorporating experts in the management plan of the forest. A number of threats to the species diversity of the forest were recorded through observation in the field and stakeholders’ interviews, such as invasive alien species (IAS) intrusion, habitat destruction, agricultural practice, and deforestation. A set of recommendations, including planting more wildlife-supporting native species, preventing the spread of IAS like Parthenium L. and incorporating experts in the forest’s management, was developed for present and future management of Purbachal Sal Forest. Bangladesh J. Plant Taxon. 31(2): 279-292, 2024 (December)

Maize Herbivore-Induced Volatiles Enhance Xenobiotic Detoxification in Larvae of Spodoptera frugiperda and S. litura

The release of herbivore-induced plant volatiles (HIPVs) has been recognized to be an important strategy for plant adaptation to herbivore attack. However, whether these induced volatiles are beneficial to insect herbivores, particularly insect larvae, is largely unknown. We used the two important highly polyphagous lepidopteran pests Spodoptera frugiperda and S. litura to evaluate the benefit on xenobiotic detoxification of larval exposure to HIPVs released by the host plant maize (Zea mays). Larval exposure of the invasive alien species S. frugiperda to maize HIPVs significantly enhanced their tolerance to all three of the well-known defensive compounds 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), chlorogenic acid, and tannic acid in maize and the two commonly used insecticides methomyl and chlorpyrifos. HIPV exposure also improved the larval tolerance of S. litura third instars to chlorogenic and tannic acids. Furthermore, larval exposure to either maize HIPVs or DIMBOA induced the activities of cytochrome P450 enzymes (P450s), glutathione-s-transferase (GST), and carboxylesterase (CarE) in the midguts and fat bodies of the two insects, while the induction was significantly higher by the two components together. In addition, the expression of four genes encoding uridine diphosphate (UDP)-glycosyltransferases (UGT33F28, UGT40L8) and P450s (CYP4d8, CYP4V2) showed similar induction patterns in S. frugiperda. Cis-3-hexen-1-ol, an important component in maize HIPVs, also showed the same functions as maize HIPVs, and its exposure increased larval xenobiotic tolerance and induced the detoxification enzymes and gene expression. Our findings demonstrate that HIPVs released by the pest-infested host plants are conductive to the xenobiotic tolerance of lepidopteran insect larvae. Hijacking the host plant HIPVs is an important strategy of the invasive alien polyphagous lepidopteran pest to counter-defend against the host plant’s chemical defense.