Green Pigment Research Articles

Assessment of Easily Accessible Spectroscopic Techniques Coupled with Multivariate Analysis for the Qualitative Characterization and Differentiation of Earth Pigments of Various Provenance

Natural minerals and earths with coloring properties have been widely used as artistic pigments since prehistoric times. Despite being extensively studied, the complex chemistry of earth pigments is still unsatisfactory described with respect to their mineralogical and structural variability and origin. In this study, a large group of earth pigments from various geographical locations was investigated using easily accessible spectroscopic techniques and multivariate analysis with the aim to identify distinctive mineralogical and chemical characteristics of natural pigment sources. Portable X-ray fluorescence (p-XRF), Fourier transform infrared spectroscopy (FTIR) and fiberoptic Raman spectroscopy were used for the elemental, molecular and structural characterization of the investigated pigments. Diagnostic spectral features and chemical patterns (fingerprints) were identified and discussed with respect to their geological sources. Due to the occurrence of similar accompanying minerals, it was observed that the differentiation of red and yellow ochers is more challenging compared to green, brown and black pigments. However, for some of the investigated pigments, the presence of certain accessory minerals and/or of certain chemical patterns can have diagnostic value. Principal component analysis (PCA) of the FTIR and XRF data matrices showed promising results in terms of geological attribution, highlighting a promising tool for provenance research. The results of the study demonstrate the potential benefits of this rapid and nondestructive approach for the characterization and differentiation of earth pigments with similar hues coming from different geological sources.

Cellulose photonic pigments

When pursuing sustainable approaches to fabricate photonic structures, nature can be used as a source of inspiration for both the nanoarchitecture and the constituent materials. Although several biomaterials have been promised as suitable candidates for photonic materials and pigments, their fabrication processes have been limited to the small to medium-scale production of films. Here, by employing a substrate-free process, structurally coloured microparticles are produced via the confined self-assembly of a cholesteric cellulose nanocrystal (CNC) suspension within emulsified microdroplets. Upon drying, the droplets undergo multiple buckling events, which allow for greater contraction of the nanostructure than predicted for a spherical geometry. This buckling, combined with a solvent or thermal post-treatment, enables the production of dispersions of vibrant red, green, and blue cellulose photonic pigments. The hierarchical structure of these pigments enables the deposition of coatings with angular independent colour, offering a consistent visual appearance across a wide range of viewing angles.

EFFECT OF EXCESS IRON (II) IONS ON PHOTOSYNTHESIS PROCESSES IN BARLEY PLANTS

It is known that all heavy metals (TM), including iron, affect the development of crops. At the same time TM affect both morphometric parameters of plants and physiological processes taking place in them. However, these processes and their changes as a result of adverse factors may differ not only in different plant species, but also in different varieties. This paper presents a study of changes in the content of chlorophylls a and b in leaves of different varieties of barley plants when excessive doses of iron (II) ions are added to the growing medium. As a result of the study, it was revealed that Fe2+ had a different effect on the content of green pigments and their ratio in the studied varieties of barley. At the same time, some varieties turned out to be more stable than others. In general, the content of chlorophyll a in the control version ranged from 17.45 (Belgorod 100) to 22.16 (29-11) mg/g; chlorophyll b - from 9.30 (Bionic) to 12.95 (29-11) mg/g. Photosynthesis processes are associated with the formation of proteins, fats and carbohydrates in plants. Therefore, this study will serve as a further basis for studying the relationship between disruptions in the processes of photosynthesis in crops and the formation of organic substances in them.

Analytical Techniques Applied to the Study of Industrial Archaeology Heritage: The Case of Plaiko Zubixe Footbridge.

In this work, micro-Raman spectroscopy and micro-energy-dispersive X-ray fluorescence spectroscopy (µ-EDXRF) were applied on microsamples taken from the Plaiko Zubixe footbridge (1927) located in Ondarroa (Basque Country, Spain) in order to investigate the original paint coating and make an evaluation of the conservation state before its restoration. Elemental and molecular images were acquired for the study of the compounds distribution. Some modern pigments such as phthalocyanine blue and green pigments, minium, calcium carbonate, Prussian blue, and hematite were identified. Barium sulfate and titanium dioxide were recognized as opacifier agents. Thanks to the study of the stratigraphies, it has been possible to determine the original paint layer, which includes lead white, ultramarine blue, carbon black, and barium sulfate. In addition, colorimetric analyses made it possible to know the CIELab values of the original layer in order to reproduce the original colour during the planned restoration work. The massive presence of chlorine detected by µ-EDXRF and the corrosion products of the rust layer, in particular akaganeite and hematite, highlighted the atmospheric impact in the conservation of the bridge because they were due to the effect of both marine aerosol and to the presence of acidic components in the environment coming from anthropogenic activity. This work demonstrated the usefulness of a scientific approach for the study of industrial archaeology heritage with the aim to contribute to its conservation and restoration.

Vitamin and mineral content of microalgae Phorpyridium and Chlorella and development prospects for food raw materials in Indonesia

Porphyridium cruentum is a product of the division of the genus Rhodophyta. It is a single cell that lives or colonizes freely in mucillago. The cells continuously secrete mucillago compounds, forming a capsule that envelops the cells. Mucillago is a sulfate polysaccharide that is soluble in water [1]. Microalgae Chlorella sp. are marine algae that can grow on fresh water and sea water media. This type of algae has a green pigment included in it class Chlorophyceae of the Chlorellaceae family. The goal of this study was to find out how much vitamin and mineral content there was in Phorpyridium and Chlorella cultivated on Conway media. The findings demonstrate that Phorpyridium has a higher vitamin E content than vitamins B1, B2, and B6. ie. 2,4 mg/100 g. Mineral analysis showed that Phorpyridium contained K minerals (45,7 mg/100g), Ca (201 g/100g), Mg (1090 mg/100g), Fe (38,2 mg/kg), Zn (3,45 mg/kg), Se (0,04 mg/kg), and P (2351 mg/kg).. Vitamin analysis of Chlorella show that vitamin B1 in Chlorella higher than Phorpyridium ie.( 3,71 mg/kg). Mineral analysis showed that Chlorella contained K minerals (714 mg/100g), Ca (331 g/100g), Mg (335 mg/100g), Fe (539 mg/kg), Zn (21,7 mg/kg), Se (0,22 mg/kg), and P (2982 mg/kg).

Plant green pigment of chlorophyllin attenuates inflammatory bowel diseases by suppressing autophagy activation in mice.

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are intestinal complications characterized by chronic inflammation, autophagy abnormality, and lysosomal stress, which are derived from genetic predisposition and environmental risk factors. It is generally precepted that dietary green vegetable is beneficial for physiological homeostasis. In this study, we found that dextran sulfate sodium (DSS)-induced colitis and altered intestinal epithelia in mice were attenuated by oral administration of chlorophyllin (CHL), a water-soluble derivate of chlorophyll. In DSS-treated mice, autophagy was persistently activated in intestinal tissues and associated with bowel disorders. Conversely, supplement of CHL in diet or gavage suppressed intestinal inflammation, downregulated autophagy flux in intestinal tissue, and relieved endoplasmic reticulum stress. In vitro studies show that CHL could activate Akt and mTOR pathways, leading to downregulation of autophagic and lysosomal flux. Thus, consumption of green vegetables and chlorophyllin may be beneficial for IBD recovery in part through alleviation of inflammation and autolysosomal flux.NEW & NOTEWORTHY Inflammatory bowel disease (IBD) is a chronic and recurrent gastrointestinal disease, while the etiology remains poorly understood. Dietary composition and lifestyle are crucial for pathogenesis and progression of IBD. In this study, we observed that autophagy in the intestinal tissue was persistently activated in IBD mice. Chlorophyllin (CHL), a water-soluble derivate of chlorophyll, can attenuate colitis by regulating autophagy and inflammation. Thus, consumption of green vegetables and chlorophyllin may be beneficial for IBD recovery.

Isolation and Identification of p-Nitrophenol Degrading Bacteria from Polluted Soil

Now-a-days due to an extensive industrialization, urbanization has leads concern towards organic pollution. Among the nitro-aromatic paranitrophenols are widely used as intermediates for the pesticides, dyes manufacturing processes. In the present study, a strain of Pseudomonas aeruginosa was isolated from the polluted soil especially in the vicinity of pesticide, chemical industry. This strain was able to utilize PNP as a sole source of carbon and energy by degrading it. The sub-culturing of these isolate on nutrient agar slants, growth on the Cetrimide agar formed well isolated colonies. The organism also gives bluish, greenish pigmentation on PIA (pseudomonas isolation agar). The organism is found to be gram-negative, exhibiting rods, motile. It is the catalase positive, MR positive, VP negative, Indole production is absent, it could utilize citrate as a sole source of carbon, it could rapidly liquefy gelatin and an oxidase negative. This studies have been showed that isolate NP1 have the ability to degrade the PNP. On the basis of the morphological, cultural and biochemical characteristics it was confirmed that the NP1 isolate have been identified as Pseudomonas aeruginosa.

Gene Therapy in Opn1mw-/-/Opn1sw-/- Mice and Implications for Blue Cone Monochromacy Patients with Deletion Mutations.

Blue cone monochromacy (BCM) is a congenital vision disorder affecting both middle-wavelength (M) and long-wavelength (L) cone photoreceptors of the human retina. BCM results from abolished expression of green and red light-sensitive visual pigments expressed in M- and L-cones, respectively. Previously, we showed that gene augmentation therapy to deliver either human L- or M-opsin rescues dorsal M-opsin dominant cone photoreceptors structurally and functionally in treated M-opsin knockout (Opn1mw-/-) mice. Although Opn1mw-/- mice represent a disease model for BCM patients with deletion mutations, at the cellular level, dorsal cones of Opn1mw-/- mice still express low levels of S-opsin, which are different from L- and M-cones of BCM patients carrying a congenital opsin deletion. To determine whether BCM cones lacking complete opsin expression from birth would benefit from AAV-mediated gene therapy, we evaluated the outcome of gene therapy, and determined the therapeutic window and longevity of rescue in a mouse model lacking both M- and S-opsin (Opn1mw-/-/Opn1sw-/-). Our data show that cones of Opn1mw-/-/Opn1sw-/- mice are viable at younger ages but undergo rapid degeneration. AAV-mediated expression of human L-opsin promoted cone outer segment regeneration and rescued cone-mediated function when mice were injected subretinally at 2 months of age or younger. Cone-mediated function and visually guided behavior were maintained for at least 8 months post-treatment. However, when mice were treated at 5 and 7 months of age, the chance and effectiveness of rescue was significantly reduced, although cones were still present in the retina. Crossing Opn1mw-/-/Opn1sw-/- mice with proteasomal activity reporter mice (UbG76V-GFP) did not reveal GFP accumulation in Opn1mw-/-/Opn1sw-/- cones eliminating impaired degradation of ubiquitinated proteins as stress factor contributing to cone loss. Our results demonstrate that AAV-mediated gene augmentation therapy can rescue cone structure and function in a mouse model with a congenital opsin deletion, but also emphasize the importance that early intervention is crucial for successful therapy.

Chemical pressure enlarged camouflage color zone in Mn(IV)-activated yellow-green pigments

Environment-friendly and cost-effective versatile yellow-green inorganic pigments are technically significant for natural camouflage but rare. Here, we adopt site-selective parent-doping of Mn–Li into the octahedral Ca-site (CaB) of Ca3TeO6 to deliver vivid greenish pigments by the unprecedented yellow-green Mn4+O6 chromophore, yielding tunable pigments resemble to seasonal leaves. The camouflage color zone of these pigments are remarkably enlarged by chemical pressure via Mg2+/Sr2+-substitution for the A-site Ca (CaA). The locally anisotropic and positive chemical pressure on chromophore group is scaled to be around +14.4/+23.3 GPa, as estimated from the accompanied geometric evolution of Mn4+O6. The achieved pigments also demonstrate excellent chemical and thermodynamic stability and high (60–80%) near infrared reflectivity in 1500–2500 nm, showing potential applications for natural camouflage and yellow-green “cool pigments”. These findings built a bridge between chemical and equivalently physical pressure, and nominated a way to estimate the overall and local strain/pressure by optical descriptor.

Novel microalgae strains from selected lower Himalayan aquatic habitats as potential sources of green products

Microalgal biomass provides a renewable source of biofuels and other green products. However, in order to realize economically viable microalgal biorefinery, strategic identification and utilization of suitable microalgal feedstock is fundamental. Here, a multi-step suboptimal screening strategy was used to target promising microalgae strains from selected freshwaters of the study area. The resulting strains were found to be affiliated to seven closely-related genera of the family Scenedesmaceae, as revealed by both morphologic and molecular characterization. Following initial screening under upper psychrophilic to optimum mesophilic (irregular temperature of 14.1 to 35.9°C) cultivation conditions, superior strains were chosen for further studies. Further cultivation of the selected strains under moderate to extreme mesophilic cultivation conditions (irregular temperature of 25.7 to 42.2°C), yielded up to 74.12 mgL-1day-1, 19.96 mgL-1day-1, 48.56%, 3.34 μg/mL and 1.20 μg/mL, for biomass productivity, lipid productivity, carbohydrate content, pigments content and carotenoids content respectively. These performances were deemed promising compared with some previous, optimum conditions-based reports. Interestingly, the fatty acids profile and the high carotenoids content of the studied strains revealed possible tolerance to the stress caused by the changing suboptimal cultivation conditions. Overall, strains AY1, CM6, LY2 and KL10 were exceptional and may present sustainable, promising feedstock for utilization in large-scale generation of green products, including biodiesel, bioethanol, pigments and dietary supplements. The findings of this study, which exposed promising, eurythermal strains, would expand the current knowledge on the search for promising microalgae strains capable of performing under the largely uncontrolled large-scale cultivation settings.

Biliverdin regulates NR2E3 and zebrafish retinal photoreceptor development

NR2E3 is an orphan nuclear receptor whose loss-of-function causes abnormal retinal photoreceptor development and degeneration. However, despite that many nuclear receptors are regulated by binding of small molecule ligands, biological small molecule ligands regulating NR2E3 have not been identified. Identification of an endogenous NR2E3 ligand might reveal a previously unrecognized component contributing to retinal development and maintenance. Here we report that biliverdin, a conserved green pigment from heme catabolism, regulates NR2E3 and is necessary for zebrafish retinal photoreceptor development. Biliverdin from retinal extracts specifically bound to NR2E3’s ligand-binding domain and induced NR2E3-dependent reporter gene expression. Inhibition of biliverdin synthesis decreased photoreceptor cell populations in zebrafish larvae, and this phenotype was alleviated by exogenously supplied biliverdin. Thus, biliverdin is an endogenous small molecule ligand for NR2E3 and a component necessary for the proper development of photoreceptor cells. This result suggests a possible role of heme metabolism in the regulation of retinal photoreceptor cell development.

Shepherd launches new yellow, blue & green inorganic pigments

Shepherd launches new yellow, blue & green inorganic pigments

Identifiable universal fluorescent multiplex PCR equipped with capillary electrophoresis for genotyping of exons 1 to 5 in human red and green pigment genes.

Congenital red and green color blindness is the most X-linked recessive disorder in humans caused by deletions or gross structural rearrangements of the visual pigment gene array that lead to altered the functions of visual pigments in their retina differ from normal. The incidence is about 7-10% in male and close association of X-linked recessive disorders (such as: hemophilia A, hemophilia B, duchenne muscular dystrophy). However, the traditional genetic analysis methods are time-consuming and low-efficiencies. Therefore, the purpose of the study is to develop a rapid method for genotyping of red and green pigment genes. We describe herein the first method for simultaneous evaluation of ten exons in the red and green pigment genes for genetic analysis. A forward specific primers with identifiable universal fluorescent multiplex PCR (FSIUFM-PCR) method utilized one universal primer (containing two universal non-human sequences) and forward specific primers in the multiplex PCR reaction system for simultaneously fluorescent labeling of eleven gene fragments (ten exons in red and green pigment genes and one internal standard). All the PCR products were analyzed on capillary electrophoresis with short-end injection, which had the advantage of high resolution and rapid separation. Of all 80 detected individuals, 7 subjects with color vision deficiencies (including 3 subjects only had red exons 1-5, 4 subjects had a specific red-green or green-red hybrid gene and 73 subjects with normal color vision). All genotyping results showed good agreement with DNA sequencing data. This method provided a better potential technique for genotyping and identifying of red and green pigment genes. In addition, FSIUFM-PCR method will be useful in many fields, such as diagnosis of diseases, analysis of polymorphisms and quantitative assay.

Investigation of photochromic pigment used for smart textile fabric

The present paper reports a physico-chemical characterization of commercial photoluminescent pigments and details their application on textile fabrics (Cotton and Cotton-PES). An eco-friendly water paste, printing and spin coating techniques were used to apply pigments on textile surface. By using X-ray diffraction diffusion data, Fourier Transform Infrared (FTIR) spectroscopy data, Scanning Electron Microscope (SEM) coupled with Energy- Dispersive X-ray (EDX) analysis, we reveal the presence of some rare earth materials particular Eu and Dy in pigments. These pigments are identified as strontium aluminate rare earth doped materials. Optical properties were conducted using spectrofluorometer for the measurements of emission, excitation and decay times. Green and blue pigments have respectively band emissions around 522 nm and 490 nm under UV excitation. The effect of applying pigments on textile fabric with different concentrations are analyzed. Relying on recorded results, pigments concentration affects the intensity of emissions without wavelength modifications. A notable pigments distribution is obtained on fabric surface using coating technique with interesting results on emission intensity. After fixation, both photoluminescent pigments demonstrate high washing resistance with a smooth surface ‘‘soft hand”. Indeed, the water-based paste is impregnated into the fibers when photoluminescent is applied. It contributed to functional printed and coating fabrics.

Analytical Investigation of Jiatang Scroll Paintings in the Seventh Year of the Guangxu Era

Jiatang scroll paintings listed in the Chinese intangible cultural heritage list are an important form of family trees. In this paper, a Jiatang scroll painting drawn in the seventh year of Guangxu (AD 1881) was chosen as a prototype to analyze its components. Samples were taken from different parts of the Jiatang scroll painting to analyze the composition of fibers, pigments, and adhesives. Herein, fiber analyzer, Fourier transform infrared spectroscopy (FTIR), and Herzberg stain were conducted to identify the type of fiber used. Microstructural and microchemical analyses by means of SEM-EDX and Raman spectroscopy were performed to characterize the pigments present in the painting, while the nature of the adhesive was examined using pyrolysis gas chromatography–mass spectrometry (Py-GC/MS). The results show that the painting fiber is from cotton, while the red, black, and green pigments were identified as cinnabar, carbon black, and emerald green, respectively. Finally, the adhesive is a mixture of animal glue, benzoin gum, and starch. The research results provide a basis for the protection and restoration of this precious cultural heritage in the future.

Impregnated layer combustion synthesis of co doped ZnO green nanopigments: Using nature-based cellulosic templates

In this research, nanostructured green pigments of ZnO and Co (CoxZn1-xO) were synthesized using impregnated layer combustion synthesis under microwave radiation. Taguchi design of experiments was employed to systematically investigate the influence of variables including the type of fuel, cobalt percentage, fuel to oxidizer ratio and type of template (impregnated active layer) to minimize the average crystallite size of particles. Three different types of fuels such as xylitol, mannitol and sorbitol as well as three templates containing filter paper, cotton and sterile gauze were used for the first time for synthesizing CoxZn1-xO nanopigments. The optimum sample with the average crystallite size of 35 nm was synthesized in specific conditions including mannitol as a fuel, filter paper as a template, cobalt percentage of 7%, fuel to oxidizer ratio of 1.3× stoichiometry. XRD analysis demonstrated that whole samples have followed ZnO pattern representative pure phases in the final structure and well-doped Co2+. FESEM images revealed the homogeneity of the nanoparticles, with average particle size of 90 nm. As a result of colorimetric studies on the optimum sample a broad reflectance band nearby 520 nm demonstrates green region with L* = 58.19, a* = −13.65, C* = 14.35 and h° = 162.07. Results showed that the pigment calcination influences the reflectance intensity effectively (∼40%). Co percentage and template type are the most important factors affecting the final green product colorimetric properties.

Possibility of direct rapid determination of inorganic contaminant elements in paints by LA-ICP-MS method

In this work content of inorganic major and trace elements were directly determined in produced in China, Russia, and Germany household use purpose oil, асгуI, and ochre paint samples using laser ablation-inductively coupled plasma-mass spectroscopy (LA_ICP_MS) technique. A sample preparation was simple and rapid: an oil and acryl paint droplets were dried on glass substrate for several hours on a hot plate at 60° C and few mg ochre paint powder samples were solidified with pure paraffin wax on the glass substrate. Dried oil and acryl paint droplets were ablated locally, drilling the hole way, while ochre paint powders were ablated using surface rastering method. Contents of inorganic elements were calculated using the NIST 610 glassy standard sample as the reference. Parallel determination results of lead and chromium in oil paint samples by atomic absorption technique correlates with that of by LA_ICP_MS acceptably (correlation coefficient for lead is 0.85 and for chromium is 0.95). Because of sample organic - reference inorganic matrix difference, the measured by the LA_ICP_MS content of each element must be adjusted being multiplied in some quantity, value of which are different for each element. For lead and chromium value of the quantity found correspondingly as 6.4 and 9.3. The average relative standard deviation (RSD) of measured content of the mostly high content elements Ca, Al, Mn, Pb, Sr, S, Mg, Fe, Sb, Na, Co, Si, Zn, Cu, P, Y, K, CI, Ce, and La is less than 10%, the RSD for elements Ti, Cr, Sn, Ba, Zr, Rb lies between 10 and 20%, and the RSD for trace elements Gd, Nb, Sc, V, U. Pr, Ni, Ga, Eu, As, Th B, Mo, Cd, Li lies in interval from 20 to 50 %. High level of concentration 309 - 24300 ppm for lead, 950- 3134 ppm for chromium are detected by LA-ICP-MS method in samples of red, yellow and green color oil paints produced in China and bestselling in Mongolia certain brand products. Up to 1900 ppm alarming high content of arsenic is tovnd in the Chinese origin yellowish red, brown red color ochre paints. As shows our measurements, the LA-ICP-MS method is possible to use as alternative rapid semi-quantitive detection method with acceptable accuracy and precision for basic inorganic additives in oil, acryl and ochre paints using glassy standard sample.

Two new species of Hypoxylon (Hypoxylaceae) from China based on morphological and DNA sequence data analyses

Two new species, Hypoxylon larissae and Hypoxylon jianfengense, are described and illustrated on the basis of a combination of morphological and molecular characters from China. Hypoxylon larissae was collected from southwest China (Yunnan province), while H. jianfengense was collected from southern China (Hainan province). Hypoxylon larissae is characterized by effused-pulvinate stromata, Orange (7) and Luteous (12) pigments extracted in 10% KOH and light brown to dark brown ascospores with straight germ slit. It is phylogenetically and morphologically closely related to H. fenderi. Hypoxylon jianfengense is distinguished by tubular to long tubular perithecia, Dark Green (21), Isabelline (65) and Dull Green (70) pigments extracted in 10% KOH and conspicuous coil-like perispore ornamentation. Hypoxylon jianfengense clustered with H. invadens and H. trugodes in a well-supported clade. Phylogenetic analyses of multi-gene sequences (ITS-LSU-RPB2-TUB2) support the recognition of the taxa as distinct.

The phthalocyanine blue-green pigments devices intended for optical filters

The crystalline structure, optical, morphological and optical filter properties of magnesium phthalocyanine (MPc) blue–green pigments layers, grown onto glass substrate by the spin coating route, are studied. Besides the capacitance voltage (C-V) characteristics and resistance versus voltage of MPc organic heterojunctions are investigated showing a negative capacitance (NC) within forward bias voltage at higher frequency. Optical analysis demonstrates a top and valley in transmittance profile within visible range which leads to the occurrence of optical filter properties in organic devices. The (123)-oriented monoclinic lattice is revealed by X-ray patterns, optical transmission attains 67% inside Vis range, and the band gap is found to be of 2.9 eV. Nonlinear optical properties of Mg-Phthalocyanine are studied. Nanotips are revealed by atomic force microscope and a size around of 22.76 nm, and the RMS is of 10.5 nm are evaluated. Obtained parameters from C-V characteristics of MgPc/GaAs heterojunction are described and recorded as a result of applied frequency. Such extracted parameters are Nd ranging in 5.1-31.2x1019 cm−3 and Vbi of 0.18-0.39 V and ΦB of 0.36 –0.41 eV.

Identification of bagworm (Metisa plana) instar stages using hyperspectral imaging and machine learning techniques

• Young larvae can be detected using hyperspectral imaging and machine learning. • The best model was obtained using green bands and weighted k-nearest neighbour. • Larvae activities gave a significant impact on the selection of the best dataset. • Larvae size is nearly identical, therefore morphological features underperform. A serious outbreak of leaf-eating insects namely bagworm (Lepidoptera: Psychidae), especially Metisa plana species, may cause a 43% yield loss in oil palm production due to late proper control of bagworm populations. Identification of the bagworm instar stage is important to ensure proper control measures are applied in the infested area. This study aims to distinguish the bagworm larvae from second (S2) to fifth (S5) instar stages using hyperspectral imaging and machine learning technique. The capability of spectral reflectance and morphological features namely area, perimeter, major axis length, and minor axis length to classify the instar stage were studied. A total of 2000 sample points of larva were extracted from hyperspectral images. It was then followed by the identification of sensitive wavelengths of each stage using analysis of variance (ANOVA). Results show that seven wavelengths from the blue and green band (i.e., 470 nm, 490 nm, 502 nm, 506 nm, 526 nm, 538 nm, and 554 nm) gave the most significant difference in distinguishing the larval instar stages. To provide a more economical approach, only two wavelengths were used for model development. Later, the classifications models were developed separately using five different types of datasets: (A) significant morphological feature, (B) all significant wavelengths, (C) two wavelengths from the same spectral region, (D) two wavelengths from different spectral regions, and (E) two significant wavelengths and a significant morphological feature. Results have shown the dataset which used green bands at 506 nm and 538 nm with a weighted k-nearest neighbour classifier achieved the best value of accuracy (91% – 95%), precision (0.83 – 0.87), sensitivity (0.77 – 0.99), specificity (0.94 – 0.96) and F1-score (0.81 – 0.91). It was mainly due to green pigments which strongly correlates with the chlorophyll content of the frond leaves fed by the larvae to build and enlarge the case. The capability of the model to detect the young larval instar stages (S2 - S3) where an active feeding activity takes place allows quick decisions about outbreak control measures.