Biotic Potential Research Articles

Effects of temperature on the development of Rachiplusia nu (Lepidoptera: Noctuidae) and Chrysodeixis includens (Lepidoptera: Noctuidae) and implications on population growth in Brazil.

Temperature is an elementary component in mathematical models for predicting the biotic potential of insects. In this study, the objective was to evaluate the impact of different constant temperatures of 8, 10, 15, 20, 25, 30, and 32°C on the biological parameters, lower temperature thresholds (TT), and estimating the number of annual generations (NAG) of Rachiplusia nu and Chrysodeixis includens, both pests associated with the soybean crop in Brazil. There was no development of the immature stages of R. nu at 8°C, as was also found for C. includens at 8 and 10°C. However, at 10°C all stages of R. nu developed. In general, temperatures of 20 and 25°C were the most suitable for the development of R. nu and C. includens, providing egg to adult viability of over 60% and the highest total fecundities. However, the temperature of 32°C negatively affected the parameters of the fertility life table. Rachiplusia nu showed the lowest TT (eggs: 4.9°C; larvae: 10.8°C; pupa: 14.1°C; and egg to adult: 8.9°C) when compared with C. includens (eggs: 7.5°C; larvae: 15.3°C; pupa: 16.1°C; and egg to adult: 11.3°C). Based on TT values, the NAG varied from 3.9 in cold regions to 7.5 in warm regions. However, for C. includens, we can infer that the species can reach up to 8.8 generations in warm regions. The results of the present study are important for understanding the occurrence of R. nu and C. includens in field conditions and can help with the implications of management strategies.

Feeding and Biotic Potential of Coccinellid Predators on Coriander Aphid

The work on feeding and biotic potential of coccinellid predators on coriander aphid was studied under ambient laboratory condition at the Department of Entomology, SKN College of Agriculture (SKNAU), Jobner and observed that the first, second, third and fourth instar grubs of Coccinella septempunctata were consume 33.60, 55.22, 129.11 and 193.88 aphids during their respective stages. A grub of C. septempunctata consumed 411.13±10.82 aphids during its total life span. The adult male and female beetles consumed 1425.50±231.82 and 1983.25±177.92 aphids during their adult longevity with daily aphid consumption ability of 54.35±2.95 and 64.14±3.90 aphids per day, respectively.

Iron Islands: The importance of iron caves in the eastern Amazon for bat conservation

AbstractThe Carajás region is home to the largest number of iron caves in Brazil, but studies that integrate elements of biological diversity and landscape characteristics are scarce. We present the first study based on the bat cave vulnerability index (BCVI), which uses bats as a key species for prioritizing caves in South America, whose objective was to assess the biotic potential and vulnerability of caves in the Carajás region, determining priority sites and the most effective conservation actions. The study took place from August 2021 to March 2023, where an inventory of the chiropterofauna of 12 caves was carried out. We recorded 16 bat species, two of which are vulnerable to extinction – Furipterus horrens (Cuvier, 1828) and Natalus macrourus (Gervais, 1856) – and two endemics to the Amazon region – Hsunycteris aff. thomasi (Allen, 1904) and Phyllostomus latifolius (Thomas, 1901); as well as one species with insufficient data to delimit its endemicity or threat status (Lonchophyllinae sp.). Mining is the main anthropogenic activity in the region, but tourism is also present and acts as a potential source of disturbance to the caves. The BCVI revealed three high priority caves for conservation and four with medium priority, indicating that these habitats are vulnerable to species loss and population decline due to exposure to anthropogenic activities and habitat destruction, thus requiring more effective conservation strategies. Considering the uniqueness of the subterranean habitats, we recommend re‐evaluating the proposals for expanding mining activities, implementing controlled tourist visitation plans and conducting ecological studies and long‐term monitoring.

A novel remote sensing-based approach to determine loss of agricultural soils due to soil sealing — a case study in Germany

Soils provide habitat, regulation and utilization functions. Therefore, Germany aims to reduce soil sealing to 30 ha day-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} by 2030 and to eliminate it by 2050. About 55 ha day-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} of soil are damaged (average 2018–2021), but detailed information on its soil quality is lacking. This study proposes a new approach using geo-information and remote sensing data to assess agricultural soil loss in Lower Saxony and Brandenburg. Soil quality is assessed based on erosion resistance, runoff regulation, filter functions, yield potential and the Müncheberg Soil Quality Rating from 2006 to 2015. Data from the German Soil Map at a scale of 1:200,000 (BÜK 200), climate, topography, CORINE Land Cover (CLC) and Imperviousness Layer (IMCC), both provided by the Copernicus Land Monitoring Service (CLMS), are used to generate information on soil functions, potentials and agricultural soil loss due to sealing. For the first time, soil losses under arable land are assessed spatially, quantitatively and qualitatively. An estimate of the qualitative loss of agricultural soil in Germany between 2006 and 2015 is obtained by intersecting the soil evaluation results with the quantitative soil loss according to IMCC. Between 2006 and 2015, about 73,300 ha of land were sealed in Germany, affecting about 37,000 ha of agricultural soils. This corresponds to a sealing rate of 11 ha per day for Germany. In Lower Saxony and Brandenburg, agricultural soils were sealed at a rate of 1.9 ha day-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} and 0.8 ha day-1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$^{-1}$$\\end{document} respectively, removing these soils from primary land use. In Lower Saxony, 75% of soils with moderate or better biotic yield potential have been removed from primary land use, while in Brandenburg this figure is as high as 88%. Implementing this approach can help decision-makers reassess sealed land and support Germany’s sustainable development strategy.

A Review on Zooplankton Diversity with Reference to Physico-Chemical Parameters of Lentic Ecosystems in Maharashtra

Zooplanktons are diverse organisms, are found more or less in all water bodies. The plankton research is a highly helpful technique for determining the biotic potential of water bodies and adds to the overall calculation of their biotic nature and general economic potential. Zooplanktons are microscopic, free-floating organisms that are essential to the functioning of aquatic ecosystems. As the most crucial link in the energy transfer between phytoplankton and higher aquatic animals, zooplanktons are significant biotic components and play a significant role in the aquatic environment. The functioning of an aquatic ecosystem's food chains, food webs, energy flow, and nutrient cycling are all influenced by zooplankton. Zooplankton populations are excellent indicators of the stability of the food chain. Numerous environmental parameters, including pH, temperature, salinity, oxygen, and others, have an impact on zooplankton. The food chain and the flow of energy between the primary and tertiary trophic levels are both significantly influenced by zooplankton. They serve as indicators of the physical, chemical, and biological processes occurring in aquatic systems due to their high densities. Because they are highly sensitive to environmental change, changes in the abundance of certain species or in the makeup of certain communities can be used to gauge the health of the environment. An assessment of the literature on zooplanktons in Indian lentic water has been done in the current work, which has long been deemed necessary in this subject.

STRATEGI PENGEMBANGAN EKOWISATA BUKIT BATU, DUSUN SUNGAI LUAR, DESA TIWINGAN BARU, KECAMATAN ARANIO, KABUPATEN BANJAR, PROVINSI KALIMANTAN SELATAN

This research aims to determine what strategies can be taken in managing Bukit Batu Ecotourism. This is because Bukit Batu Ecotourism has considerable potential, including biotic potential such as flora and fauna as well as abiotic potential such as mountains, hills, rivers, forests and lakes which of course have an attraction for tourists. The analytical method used in this research is a qualitative descriptive method. Where this research activity was carried out in natural and uncontrived object conditions, then the data obtained was analyzed using SWOT analysis. the SO strategy in order of priority which is described as follows: (1) Create tourist attractions and attractions that display ecological potential and diversity of flora and fauna such asaviary (giant bird cages), a mini zoo, an aquarium that accommodates local fish species and a miniature Borneo rainforest featuring endemic plant species. (2) Make a viewing tower to enjoy the beautylandscape mountains and lakes as a whole. (3) Empowering the surrounding community in managing Ecotourism such as retribution officers, cleaning officers and security officers. (4) Make plans for the development of facilities and infrastructure based on the most important priorities, such as telecommunication and internet signal booster towers, repair of roads that are still damaged and street lighting. (5) Increase safety warning boards. And (6) Empowerment of BUMDES (Village-Owned Enterprises) with clear work contracts so that they can have an impact on increasing the economy of the surrounding community, such as providing boat rental services, tour guides, bicycle/tent rental and selling souvenirs.

Evaluation of cupcakes bioavailability and nutritional value

Numerous studies aimed at expanding the production of domestic healthy food products meet the objectives of national programs and projects implemented at the state level. Flour confectionery products are known to be an integral part of the food basket of our country's inhabitants. Therefore, the use of non-traditional vegetable raw materials with a high content of fiber, vitamins, and minerals in their manufacture is an important research field. In addition, these technologies are resource-saving and allow expanding the range of products for specialized and therapeutic purposes, including those for people with gluten intolerance. However, it should be mentioned that the introduction of additional raw materials is an interference with the traditional cooking technology and may affect the finished product quality, which requires additional research. Therefore, the effect of biologically active components on the bioavailability and nutritional value of a cupcake enriched with non-traditional types of raw materials was studied in the work. The ciliates P. caudatum were used as a test object for assessing the studied samples bioavailability. In addition, indicators of nutritional and energy value were determined in finished products. The studies carried out proved that the use of whole wheat flour, grape seed flour, sesame oil and sesame seeds in the production of cupcakes helps to increase its biotic potential, biological and nutritional value.

Biotic potential of Transeius montdorensis (Acari: Phytoseiidae) under technocenosis conditions

The subtropical mite species Transeius montdorensis is widely used to control thrips and other sucking pests in European countries. To develop a domestic technology for the mass rearing of T. montdorensis, its biotic potential has been evaluated under large scale production. The growth rate of T. montdorensis is 0.19±0.017, the doubling time is 4.7±0.29 days at 26–27 °C. In the tested range of mite densities (5–80 ind./ml), the growth rate tends to decrease as the density increases. This trend can be approximated by a logarithmic curve. The density 60–80 ind./ml causes not only a significant drop in the population growth rate but also the decrease in range of its fluctuations. Higher fluctuations of growth rate at lower predator densities (5–15 ind./ml) are probably due to the fact that, in some containers, the predator is unable to hold back outbreaks of its prey (the flour mite Tyrophagus entomophagus). As a result, the prey overpopulates the substrate, which causes its contamination by waste products stimulating microflora development. The growth rate in the density range of 5–15 ind./ml is lower than expected and does not differ significantly from that in the range of 20–30 ind./ml. This indicates that the prey uncontrolled growth inhibit the reproduction of T. montdorensis. The population doubling time is a reliable indicator for screening the best stock culture of T. montdorensis for its successful rearing up to density 60 ind./ml within 6–8 days, i.e., before mass growth of fungi in the substrate. The range of 20–30 ind./ml is the optimal starting density for mass rearing, and when the predator reaches a density of more than 60 ind./ml, it should be resettled or offered for sale.

Influence of forest fire smoke on the decline of biodiversity and the state of living organisms (literary review)

Introduction. The relevance of this work is due to the growing environmental problem associated with large-scale forest fires and insufficient knowledge of the survival, adaptation and reproduction of animals after prolonged exposure to harmful smoke components.
 The aim of the review is to collect and analyze information on environmental pollution due to smoke from forest fires and their impact on animals in the smoke zone. 
 Material and methods. The material for the analysis was the literature sources published for the period up to 2022, in publications indexed in the Scopus, Web of Science, Publons, Springer, PubMed databases, including domestic and foreign research scientists on this topic.
 Results. When forest fires occur, a mixture of gaseous compounds is released into the environment, containing ultrafine solid particles, carbon monoxide, ozone, polycyclic aromatic hydrocarbons, nitrogen and sulfur dioxide, aldehydes, chlorinated dioxins, free radicals and many other compounds. At the same time, significant damage is caused to a wide biodiversity of the animal world, which is an extremely important indicator link in almost any biocenosis.
 Conclusions. The increase in large-scale smoke is increasingly leading to the risk of extinction of wildlife exposed to high concentrations of toxic components of smoke. It is necessary to constantly maintain and restore the biotic potential of populations of endangered species in forest ecosystems, as well as a deeper study of the mechanisms of the occurrence of consequences that are dangerous for the animal organism when exposed to forest fire smoke.

Transgenerational effect of Afidopyropen on Bemisia tabaci Gennadius (Homoptera: Aleyrodidae)

Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) is the most devastating insect-pest in cotton crop. It is vector of the cotton leaf curl virus (CLCV) and is responsible for huge losses to cotton industry in Pakistan and worldwide. It is mainly controlled by insecticides but the injudicious use of insecticides has resulted in insecticide resistance and population resurgence in addition to various harmful effects on the humans, non-target organisms and the environment. Transgenerational studies are very helpful to choose a best insecticidal option. In the current study, age-stage two-sex life table analysis was used to identify transgenerational effects of sublethal doses of afidopyropen. The adults of B. tabaci were treated with three concentrations of afidopyropen i.e., LC10, LC30 and LC50. The results indicated significant changes in the progeny i.e. the fecundity decreased in treated population; and female and male longevity of their progeny were more in control as compared to treated populations. Similarly, population parameters like intrinsic rate of growth (r), net reproductive rate (R0) and limiting rate of growth (λ) were significantly decreased in the treated adult progeny with values of 0.08–0.11, 4.85–7.46 and 1.09–1.12 per day, respectively. Based on the reduced biotic potential, afidopyropen can be suggested as an effective alternative option for the management of B. tabaci.

Ibuprofen-enhanced biodegradation in solution and sewage sludge by a mineralizing microbial consortium. Shift in associated bacterial communities

Ibuprofen (IBP) is a widely used drug of environmental concern as emerging contaminant due to its low elimination rates by wastewater treatment plants (WWTPs), leading to the contamination of the environment, where IBP is introduced mainly from wastewater discharge and sewage sludge used as fertilizer. This study describes the application of a consortium from sewage sludge and acclimated with ibuprofen (consortium C7) to accelerate its biodegradation both in solution and sewage sludge. 500 mg L-1 IBP was degraded in solution in 28 h, and 66% mineralized in 3 days. IBP adsorbed in sewage sludge (10 mg kg-1) was removed after bioaugmentation with C7 up to 90% in 16 days, with a 5-fold increase in degradation rate. This is the first time that bioaugmentation with bacterial consortia or isolated bacterial strains have been used for IBP degradation in sewage sludge. The bacterial community of consortium C7 was significantly enriched in Sphingomonas wittichii, Bordetella petrii, Pseudomonas stutzeri and Bosea genosp. after IBP degradation, with a special increase in abundance of S. wittichii, probably the main potential bacterial specie responsible for IBP mineralization. Thirteen bacterial strains were isolated from C7 consortium. All of them degraded IBP in presence of glucose, especially Labrys neptuniae. Eight of these bacterial strains (B. tritici, L. neptuniae, S. zoogloeoides, B. petrii, A. denitrificans, S. acidaminiphila, P. nitroreducens, C. flaccumfaciens) had not been previously described as IBP-degraders. The bacterial community that makes up the indigenous consortium C7 appears to have a highly efficient biotic degradation potential to facilitate bioremediation of ibuprofen in contaminated effluents as well as in sewage sludge generated in WWTPs.

Demographic study of the box tree moth Cydalima perspectalis (Lepidoptera: Crambidae) feeding on Buxus hyrcana (Buxales: Buxaceae)

Abstract Cydalima perspectalis (Walker 1859) (Lepidoptera: Crambidae) is a destructive pest that has recently been reported from the ancient Hyrcanian forests feeding on leaves and shoots of Buxus hyrcana Pojarkova. To gain a deeper insight into the biology and population dynamics of C. perspectalis, a laboratory population was studied under controlled conditions. The moth was reared on B. hyrcana at 25 ± 1°C, 65 ± 10% RH and 16 h:8 h (L:D), and the data obtained were used to build a life table, adjusted to allow for the evaluation of the stage duration, for both males and females. The mean adult survival was 11.94 ± 0.26 days, the pre‐oviposition period lasted, on average, for 6.71 ± 0.18 days and the mean fecundity attained was 58.19 ± 7.81 eggs/female. Newly emerged females had a life expectancy (exj) of 14 days and males 19 days. The intrinsic rate of increase for the population was 0.05 ± 0.00 days−1, and the net reproductive rate was 24.05 ± 3.95 offspring/female. The biological and ecological data obtained allowed for the estimation of C. perspectalis biotic potential, thus contributing to the development of sustainable control methods for this pest and, consequently, to a reduction of the damage caused to box trees.

Insights into sublethal effects of Metarhizium anisopliae on the biotic potentials of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) on maize

BackgroundEntomopathogenic fungi are an important biological agent in integrated pest management, playing a critical role in controlling insect populations. In the present study, the sublethal effects of the entomopathogenic fungus, Metarhizium anisopliae (Ascomycota: Hypocreales), were investigated on the biotic potential of Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), which is a major pest of economically important crops.ResultsObtained results revealed that exposure to LC50 concentration of M. anisopliae resulted in a significantly longer larval developmental time (3.25–6.45 days) than the control group (2.42–5.49 days). Similarly, pupal duration was longer in the LC50 treatment (8.24 days) than in the control (6.91 days). Adult longevity was also significantly reduced in the LC50 (9.64 days) and LC30 (10.49 days) treatments compared to the control group (11.7 days). The number of eggs laid by female S. frugiperda exposed to LC50 value of M. anisopliae during the immature stages was significantly lower (464.79 eggs) than that in the control groups (696.93 eggs). Furthermore, all population and age-stage-specific parameters were significantly affected by the sublethal exposure to M. anisopliae at LC30 and LC50 values.ConclusionThese results suggest that sublethal exposure to M. anisopliae negatively impacts the life table parameters of S. frugiperda. However, the use of M. anisopliae at sublethal levels may have potential benefits for integrated pest management strategies seeking to reduce the use of chemicals.

Biotic potential and pathogenicity of a Haemonchus contortus susceptible laboratory isolate compared to a resistant field isolate in Brazil

The high prevalence of anthelmintic resistance of Haemonchus contortus is threatening sheep farming. In this context, resistant populations’ replacement using susceptible isolates appears to be a strategy to overcome this situation. The aim of the present study was to evaluate the ability of a susceptible H. contortus laboratory isolate in comparison with a multiresistant field isolate to infect lambs and to study its behaviour in field conditions. Sixteen worm-free lambs were experimentally infected with 4000 infective larvae (L3) of a H. contortus anthelmintic-resistant field isolate (Group R, n = 8) or a laboratory isolate susceptible to anthelmintics (Group S, n = 8). Groups were placed in separate clean pastures, where they were kept for 266 days. Faecal egg counts (FEC) showed maximum values between 21- and 42-days post-infection (PI) and decreased over time, with no statistical differences between groups (P > 0.05). The pathogenicity of the isolates was similar, as lambs from both groups showed a decrease in packed cell volume and total plasma protein values in the beginning of the study, coinciding with the highest FECs. Production of L3 were similar for both groups, when evaluating faecal cultures kept in vitro or L3 recovered from pasture samples and from faecal pats collected from the paddocks, which suggests that both isolates have the same potential of development in vitro and in the environment. The degree of resistance/susceptibility to thiabendazole (TIA), levamisole (LEV), monepantel (MON) and ivermectin (IVE) was evaluated using the Larval Development Assay (RESISTA-Test©) 160 days PI. The resistant isolate showed a high resistance factor (RF) to TIA (141), LEV (822), MON (34) and IVE (196), while the RF of the susceptible isolate remained below three, which indicates high susceptibility to all drugs tested. Our study demonstrates that the susceptible isolate was able to infect lambs and did not show higher pathogenicity nor any differences on its biotic potential when compared to the resistant field isolate. These results indicate that the susceptible isolate has the potential to be used to replace a resistant population of H. contortus, which should be validated in long-term studies under commercial sheep farming conditions.

A matter of scale: Local biotic differentiation and potential regional homogenization of understory plant communities in a highly fragmented tropical landscape

Plant communities in highly fragmented tropical landscapes can undergo biotic homogenization and differentiation after land-use changes, such as forest fragmentation. Here we evaluated the beta diversity of understory plant communities in fragmented forest remnants and assessed species geographic distribution to infer potential local and regional scale dependency of homogenization and differentiation pathways in the Atlantic Forest in southern Brazil. More specifically we assessed: (i) community composition; (ii) the frequency of locally rare species, generalists, interior and edge specialists; (iii) the relative contribution of beta diversity components; and (iv) the influence of widely, intermediate and narrowly distributed species to the observed patterns. Understory communities were sampled in a nested design with plots allocated to the interior and edge of forest fragments, and geographic distributions were estimated based on occurrence records from herbaria collections. Our results revealed differences in species composition among fragments and habitat types (edge and interior). Most of the sampled species were classified as locally rare. The turnover component of beta diversity explained a higher proportion of variation in species composition among fragments and habitats. Species richness and abundance were higher in the interior of fragments and most of the recorded species in the study had a wide geographic distribution. Our results support a local community differentiation (high beta diversity) among fragments and habitat types and suggest a potential regional homogenization, given the predominance of widely distributed generalist species in a domain historically characterized by high levels of endemism. We recommend urgent protection and restoration actions on the few remaining fragments of the Atlantic Forest given that each remnant can support different plant assemblages that have been increasingly threatened. Future studies should explicitly consider multiple spatial and temporal scales across fragmented tropical landscapes to better understand links with biotic homogenization and differentiation of ecological communities.

Diversity and Biotic Index of Wild Pioneer Plants as Potential Bioindicators of Crude Oil-Contaminated Soil in Siak Regency, Riau Province, Indonesia

This study aims to determine the spatial variations in the diversity of wild pioneer plants along the gradation of crude oil-polluted soils and to analyze their biotic potential as a bioindicator of crude oil-contaminated soils in Siak Regency. Sampling was done in three oil wells using a purposive sampling method (center, edge, far from the well) measuring 1 x 1 m2. The soil at each contamination gradation was composited and analyzed for Total Petroleum Hydrocarbon (TPH) content. Vegetation data were analyzed using biotic indices such as density, Shannon-Wiener distribution index, species richness, rate of endemism, and importance value index. Potential bioindicator was analyzed by regression analysis, biplot, and IndVal. The results showed spatial variations in colonization, diversity, and structure of pioneer plants along the gradation of oil contamination. Species from the Cyperaceae, notably Scleria sumatrensis, Cyperus rotundus, and Fimbristylis ovata, were found in the center of the contamination area and resistant to oil contamination. The regression and biplot analysis revealed that along with the increasing soil TPH, the species richness and diversity index tended to decline, but the rate of endemism increased. IndVal analysis showed that C. rotundus and S. sumatrensis showed a potential bioindicators of oil-contaminated soils with TPH content of 2,700 to 3,300 ppm, while F. ovata, Panicum repens, and Imperata cylindrica was potential for TPH 692 to 851 ppm. Mimosa pudica was a sensitive plant and found on the soil TPH 73 ppm.

Diversity and Biotic Index of Wild Pioneer Plants as Potential Bioindicators of Crude Oil-Contaminated Soil in Siak Regency, Riau Province, Indonesia

This study aims to determine the spatial variations in the diversity of wild pioneer plants along the gradation of crude oil-polluted soils and to analyze their biotic potential as a bioindicator of crude oil-contaminated soils in Siak Regency. Sampling was done in three oil wells using a purposive sampling method (center, edge, far from the well) measuring 1 x 1 m2. The soil at each contamination gradation was composited and analyzed for Total Petroleum Hydrocarbon (TPH) content. Vegetation data were analyzed using biotic indices such as density, Shannon-Wiener distribution index, species richness, rate of endemism, and importance value index. Potential bioindicator was analyzed by regression analysis, biplot, and IndVal. The results showed spatial variations in colonization, diversity, and structure of pioneer plants along the gradation of oil contamination. Species from the Cyperaceae, notably Scleria sumatrensis, Cyperus rotundus, and Fimbristylis ovata, were found in the center of the contamination area and resistant to oil contamination. The regression and biplot analysis revealed that along with the increasing soil TPH, the species richness and diversity index tended to decline, but the rate of endemism increased. IndVal analysis showed that C. rotundus and S. sumatrensis showed a potential bioindicators of oil-contaminated soils with TPH content of 2,700 to 3,300 ppm, while F. ovata, Panicum repens, and Imperata cylindrica was potential for TPH 692 to 851 ppm. Mimosa pudica was a sensitive plant and found on the soil TPH 73 ppm.

Molecular identification, life history description and biotic potential of Plodia interpunctella (Lepidoptera: Pyralidae) feeding on amaranth (Amaranthus sp.) products in the state of Morelos, Mexico

The flour moth Plodia interpunctella (Hübner) is considered one of the most significant pests of stored and processed products, its adaptability allowing it to settle on new food hosts. In 2020 in Mexico, the presence of larvae and adults of P. interpunctella in amaranth products stored and processed for export was reported for the first time, causing considerable damage. The objective of this study was molecular identification of the insects found in amaranth products and description of the biotic potential of these pests grown in different amaranth products under laboratory conditions. For this purpose, molecular identification of P. interpunctella was carried out using the mitochondrial gene cytochrome oxidase subunit one (COI). Three cohorts with 200 eggs each, fed with three types of amaranth products (amaranth with chocolate, amaranth with honey and natural amaranth) were implemented, with hatching rates of 75% for amaranth with chocolate, 66.5% for amaranth with honey and 71.5% for natural amaranth. The larval period consisted of five instars and one prepupa, with the shortest life expectancy in the first instar. The life cycle of the insect varied from 51 days in chocolate amaranth, 54 days in honey amaranth and 64 days in natural amaranth. This lepidopteran presented a high fecundity when fed with chocolate amaranth with a mean clutch size of 257.0435.98 eggs per female during her whole life (h/h/v), followed by honey amaranth with 177.3836.23 (h/h/v) and finally by natural amaranth with 157.643.33 (h/h/v), with a mean fertility of 71%. In the population parameters, a generation time (T) of 25.08, 26.69 and 31.41 days and a net reproduction rate (R0) of 405.10, 253.82 and 215.49 were obtained for amaranth with chocolate, with honey and natural respectively, ensuring a high replacement over a short period of time; these values make this species an important pest of stored amaranth products.

Non-host plant odors influence the tritrophic interaction between tomato, its foliar herbivore Tuta absoluta and mirid predator Nesidiocoris tenuis.

The tomato leafminer, Tuta absoluta is a destructive invasive pest of cultivated tomato and other Solanaceae plants, with yield losses of 80-100%. Mirid predators are key natural enemies of T. absoluta, but they also feed on host plants in the absence of their prey. Management of T. absoluta is a challenge due to its high biotic potential, resistance to many insecticides and the absence of sufficiently adapted auxiliary fauna in its new dispersion zones. Olfaction plays an important role in the tritrophic interaction between tomato, its herbivore pest T. absoluta and its mirid predators, which can be influenced by non-host plant odors. However, how non-host odours shape this interaction is poorly understood. Previously, we had demonstrated belowground crop protection properties of certain Asteraceae plants against the root-knot nematode Meloidogyne incognita, pest of tomato and other Solanaceae plants. Additionally, Asteraceae plants impact negatively on feeding behavior of above-ground pests of Solanaceae plants, including the greenhouse whitefly (Trialeurodes vaporariorum) and green peach aphid (Myzus persicae). Here, we tested the hypothesis that foliar volatiles from some of these non-host Asteraceae plants can influence the tomato-T. absoluta-mirid predator tritrophic interaction. In olfactometer assays, T. absoluta females were attracted to volatiles of the Solanaceae host plants tomato and giant nightshade but avoided volatiles of the Asteraceae plants, blackjack and marigold, and the positive control, wild tomato, when tested alone or in combination with the host plants. Coupled gas chromatography-mass spectrometry analysis showed that host and non-host plants varied in their emission of volatiles, mainly monoterpenes and sesquiterpenes. Random forest analysis combined with behavioral assays identified monoterpenes as the host plant attractive blend to T. absoluta and its mirid predator, with sesquiterpenes identified as the non-host plant repellent blend against T. absoluta. Contrastingly, the mirid predator was indifferent to the non-host plant repellent sesquiterpenes. Our findings indicate that terpenes influence the tomato-T. absoluta-mirid predator tritrophic interaction. Further, our results emphasize the importance of studying crop protection from a holistic approach to identify companion crops that serve multi-functional roles.

Rice husk as a potential source of silicate to oceanic phytoplankton

Global oceans are witnessing changes in the phytoplankton community composition due to various environmental stressors such as rising temperature, stratification, nutrient limitation, and ocean acidification. The Arabian Sea is undergoing changes in its phytoplankton community composition, especially during winter, with the diatoms being replaced by harmful algal blooms (HABs) of dinoflagellates. Recent studies have already highlighted dissolved silicate (DSi) limitation and change in Silicon (Si)/Nitrogen (N) ratios as the factors responsible for the observed changes in the phytoplankton community in the Arabian Sea. Our investigation also revealed Si/N < 1 in the northern Arabian Sea, indicating DSi limitation, especially during winter. Here, we demonstrate that rice husk with its phytoliths is an important source of bioavailable DSi for oceanic phytoplankton. Our experiment showed that a rice husk can release ∼12 μM of DSi in 15 days and can release DSi for ∼20 days. The DSi availability increased diatom abundance up to ∼9 times. The major benefitted diatom species from DSi enrichment were Nitzshia spp., Striatella spp., Navicula spp., Dactiliosolen spp., and Leptocylindrus spp. The increase in diatom abundance was accompanied by an increase in fucoxanthin and dimethyl sulphide (DMS), an anti-greenhouse gas. Thus, the rice husk with its buoyancy and slow DSi release has the potential to reduce HABs, and increase diatoms and fishery resources in addition to carbon dioxide (CO2) sequestration in DSi-limited oceanic regions such as the Arabian Sea. Rice husk if released at the formation site of the Subantarctic mode water in the Southern Ocean could supply DSi to the thermocline in the global oceans thereby increasing diatom blooms and consequently the biotic carbon sequestration potential of the entire ocean.