Monophagous Insect Research Articles

Impact of leaves of different mulberry genotypes on nutritional efficiency of conversion parameters of silkworm, Bombyx mori L.

The silkworm, Bombyx mori, is a domesticated insect widely used to produce silk worldwide for human consumption. B. mori is a monophagous insect that feeds on nutritious mulberry leaves to produce silk. The efficiency of conversion of leaves to larval biomass by silkworm larva largely depends upon the type of silkworm breed/hybrid and the quality of mulberry leaves fed to them. The silkworms having good efficiency of conversion of leaves perform better in larval growth and silk gland development, which finally leads to enhanced silk production. In the current research work, the highest efficiency of conversion of ingesta to larva (28.608%) and efficiency of conversion of digesta to larva (51.527%) were found in Goshoerami fed silkworm batch which differed significantly from other varieties.

Volatolomics to Decrypt the Monophagous Nature of a Rice Pest, Scirpophaga Incertulas (Walker).

Scirpophaga incertulas Walker (Lepidoptera: Crambidae, yellow stem borer, YSB) is a monophagous insect pest that causes significant yield loss in rice (Oryza staiva L.). Semiochemical based pest management is being sought as an alternate to chemical pesticides to reduce pesticide footprints. We hypothesized differential release of volatiles from host rice and two companion non-host weeds, Echinochloa colona and Echinochloa crus-galli could be responsible for oviposition and biology of YSB and these chemicals could be used for YSB management. Number of eggs laid, and number of larvae hatched were significantly higher in rice plant as compared to weeds. YSB could only form dead hearts in rice plants. YSB significantly preferred host-plant volatiles compared to the non-host plants both in choice and no-choice tests in an Y-tube olfactometer. 2-Hexenal, hexanal, 2,4-hexadienal, benzaldehyde, nonanal, methyl salicylate and decanal were found in the leaf volatolomes of both the host and non-host plants in HS-SPME-GC-MS (Headspace-Solid phase micro extraction-Gas chromatography-Mass spectrometer). Pentene-3-one, 2-pentyl furan, 2,4-heptadienal, 2-octenal, 2-octenol and menthol were present only in the non-host plants. Fourteen rice unique compounds were also detected. The built-in PCA (Principal Component Analysis) and PLS-DA (Partial least squares-discriminant analysis) analysis in the MS-DIAL tool showed that the volatiles emitted from TN1 formed a cluster distinct from Echinochloa spp. and 2-octenal was identified as a unique compound. Olfactometer bioassays using synthetic compounds showed that rice unique compounds, like xylene, hexanal served as attractants whereas non-host unique compounds, like 2-pentylfuran, 2-octenal acted as repellent. The results indicate that the rice unique compounds xylene, hexanal along with other volatile compounds could be responsible for higher preference of YSB towards rice plants. Similarly, the non-host unique compounds 2-pentylfuran, 2-octenal could possibly be responsible for lower preference and defence against YSB. These compounds could be utilised for devising traps for YSB monitoring and management.

Infestation Rate of the Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae) in South India

The coffee berry borer (CBB), Hypothenemus hampei, is a monophagous insect pest that poses a major threat to coffee production worldwide, causing yield losses of up to 30-50%. India's coffee heartland in the south, responsible for over 90% of the national output, grapples with the threat of CBB infestations. Despite its economic importance and global spread, research on the ecology of CBB in India's traditional coffee-growing regions still needs to be completed. In this study, we investigated the infestation rate of CBB in Coffea arabica and C. canephora plantations at three designated locations at Chikkamagaluru (Karnataka), Thandigudi (Tamil Nadu) and Chundale (Kerala) from south India and samplings was done once a month during three fruiting periods between 2015 and 2018. The three sampled sites showed variable percentages of infestation rates across the sampling period between 4.61±0.73 and 29.60±2.28, with the lowest and highest infestation rates in Thandigudi and Chikkamagaluru, respectively. The increase in CBB infestation towards harvest and variations in pre-brood, brood, and post-brood populations suggest the influence of different stages of fresh coffee berries, favorable agro-climatic conditions, and gaps in management strategies in the three sampled regions.

Effect of Spring Goshoerami Mulberry Leaf Extract on Second Commercial Cocoon Crop under Temperate Climatic Condition

Nutrition plays an important role in silkworm rearing. It improves the growth, development, health and feed consumption, thereby improving the commercial traits. As reported, the mulberry leaf under Kashmir climatic condition during Summer/autumn season is nutritionally poor. In Kashmir Valley 90% of silkworm rearers mostly do rearing only once in a year i.e during spring season and lesser number of rearers goes for second rearing during summer/ autumn season because of less productivity and poor quality cocoon crops. Fortification of leaves by supplementing nutrients and using them for feeding the silkworm is a useful technique to increase their economic value. Several attempts have been made to enhance the cocoon yield and silk content through supplement of amino acids on mulberry leaf. However supplement of amino acids on mulberry leaf may not be economical and is not easily assessable to farmers. Silkworm, Bombyx mori L., is a monophagous insect that drives all required nutrients for its growth and development from mulberry leaf. Hence the present study was undertaken to study the efficacy of fortification of spring leaf extract of Goshoerami on growth and commercial traits of double hybrid FC1 (CSR6×CSR26) × FC2 (CSR2×CSR27) of silkworm Bombyx mori L. during second commercial rearing. The results showed, that application of aqueous extract of spring mulberry leaf fed silkworm larvae shows significantly higher in terms of body weight, cocoon weight, shell weight, yield and silk filament length in all the treatments over the control. However the highest body weight (44.143 g/10) mature larval, Single cocoon weight (1.967g), single shell weight (0.471g), shell ratio percentage (23.921 %) and silk filament length (1,159.66 mtr) were recorded at 10% fortification. In order to promote the use of spring leaf extract for fortification among the silkworm rearers further studies are required in consultation with Department of Sericulture of the U T of Jammu and Kashmir.

Effects of invasive plant haplotypes on a biological control agent (Lepidelphax pistiae) fecundity and impact

ABSTRACT Pistia stratiotes L. is an invasive floating plant that alters native habitats in Florida by forming thick mats that shade out submerged vegetation and obstruct navigation. Multiple genotypes of this plant have been identified from locations across its native and adventive ranges including types from throughout the Americas, the Caribbean, Asia, and Australia. We investigated the performance of a known monophagous insect, Lepidelphax pistiae, on nine P. stratiotes haplotypes (from four clades) in no-choice experiments and found that while L. pistiae performance varied on different haplotypes, there was considerable overlap in fitness and impact among haplotypes. Lepidelphax pistiae did not distinguish between purported ‘native’ and ‘non-native’ haplotypes and did not perform better or cause more damage to South American haplotypes specifically, which would have supported its utility as a biocontrol agent on the exotic haplotypes found in Florida. While L. pistiae is monophagous on P. stratiotes, it was not specific enough to differentiate consistently among the tested haplotypes and thus, may not be suitable as a biological control agent because of the potential threat they pose to native haplotypes of P. stratiotes in Florida.

Physiological harmfulness of xylophagous insects in poplar and aspen stands in the Left-Bank Forest-Steppe

Introduction
 Poplars and aspens (Populus sp.) are common in forest stands, shelterbelts, rural landscaping, and in special plantations as short-rotation woody crops; they are promising tree species for biofuel and bioenergy production. Wood-boring insects browse galleries in a stem or branches that interrupt sap circulation and promote infestation by plant pathogens. Some of these insects can additionally weaken trees using foliage, bark, or phloem for maturation feeding. All these effects comprise the physiological harmfulness of wood-boring insects, whereas their technical harmfulness depends on the size and depth of the galleries, their location at the stem, and the timber value of a given tree species.
 The approach of wood-boring insect harmfulness assessment was suggested by E. Mozolevskaya and it is implemented for oak, pine, spruce, birch, and elm. It was shown that the harmfulness of the same insect species varies significantly depending on environmental conditions and population density.
 The aim of the research was to evaluate the physiological harmfulness of xylophagous insects for Populus sp. in the Left-Bank Forest-Steppe considering the ability of these insects to colonize and damage trees under certain health, transmit the pathogens, as well as host range and occurrence.
 Materials and Methods
 The research was carried out in 2019–2022 in Poltava, Sumy, and Kharkiv regions at the archive plantation of poplar clones, forest stands, and forest shelterbelts. The collections and research of Yu. Skrylnik since 2006 in the specified territories were also included in the analysis. In the analysis, only those insect species were used, for which the development in the stems and branches of Populus sp. was proved by our research and/or supported by publications. The range of host plants and the occurrence of insects were estimated. Their physiological harmfulness was calculated as the sum of scores for their physiological activity (ability to colonize trees under certain health condition), ability to damage the trees during maturation feeding, and ability to vector the pathogens.
 Results and Conclusions
 In the study, 72 insect species were analyzed, particularly 40 Cerambycidae, 19 Buprestidae, 7 Curculionidae, 2 Sesiidae, and 3 Cossidae. The proportion of abundant species was the highest among Scolytinae: Xyleborini. Species with a high physiological activity predominate among monophagous insects, particularly, Agrilus suvorovi, Cryptorhynchus lapathi, Xyleborus cryptographus, Paranthrene tabaniformis, Acossus terebra. Only five species (S. populnea, S. octopunctata, S. perforata, S. scalaris, S. carcharias) can cause significant damage to trees during maturation feeding by foliage or bark of branches. The average score of physiological harmfulness is the highest among abundant xylophagous species, it is almost twice as low in common species, and almost two times less in rare and single species. High physiological harmfulness (10 and more) for poplars and aspens is estimated for nineteen xylophagous species, particularly, 13 for S. populnea and S. carcharias, and 12 for Cryptorhynchus lapathi, Trypodendron signatum, Tremex fuscicornis, and Xyleborini species.
 3 Tab., 4 Fig., 35 Ref.

Morphological Characterstics of the Sensilla in a Monophagous Insect: Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae, Halticinae).

Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae) is the key natural enemy of Alternanthera philoxeroides (Mart.) Griseb, an invasive weed worldwide. To understand the morphology of A. hygrophila and further explore the specific host localization mechanism, scanning electron microscopy was used to observe and study the morphological characteristics of sensilla on the head appendages, tarsi, and external genital segments of A. hygrophila. Twelve types and forty-six subtypes of sensilla were observed. These contain various types of head appendices, including sensilla chaetica, sensilla trichodea, sensilla basiconca, sensilla coeloconica, sensilla styloconica, Böhm bristles, sensilla campaniform, sensilla terminal, sensilla dome, sensilla digit-like, sensilla aperture, and many subtypes. A new type of sensor was reported for the first time, which may be related to host plant recognition. This sensor was located on the distal segment of the maxillary palps of A. hygrophila and was named as sensilla petal-shaped based on its morphological characteristics. Sensilla chaetica, sensilla trichodea, and sensilla basiconca are also found on the tarsi and external genital segments. In addition, sensilla basiconica 4, sensilla coeloconica 1 and 2, sensilla styloconica 2, Böhm bristles 2, and sensilla campaniform 1 were only found in females. On the contrary, sensilla styloconica 3, sensilla coeloconica 3, and sensilla dome were only found in males. Numbers and sizes of the sensilla were also different between males and females. The potential functions related to structure were discussed in comparison with previous investigations on beetles and other monophagous insects. Our results provide a microscopic morphological basis for further research on the localization and recognition mechanism of A. hygrophila and its obligate host.

Evaluation of Rice Genotypes Resistance to Yellow Stem Borer, Scirpophaga incertulas (Walker) through Sex Pheromone Trap

Yellow stem borer, Scirpophaga incertulas (Walker) is monophagous insect pest causing serious damage to rice growers of plain regions of Nepal. This study was done to evaluate the host preference of yellow stem borer to the various genotypes of rice. The research design employed was Randomized Complete Block Design (RCBD) with seven treatments and three replications and done in kharif season of 2021. Rice varieties selected were Sabitri, Sarju 52, US 312, Radha 4, Sawa Mansuli, Silki and Hardinath 3, which are popularly cultivated in Kailali. Sex pheromone trap (scirpolure) was installed to monitor the preference of yellow stem borer for various rice varieties, especially at the panicle initiation stage of rice. Statistical analysis of four weeks data of adult male moths trapped on different cultivars of rice revealed that the yellow stem borer adult moths were highly attracted to the US 312 and less attracted to Sarju 52 and Silki varieties. This research implied that the adoption of popular rice variety Sarju 52 could safeguard the farmers from the notorious pest i.e. yellow stem borer of rice.

INVESTIGATION ON CONVERSION EFFICIENCIES OF MULBERRY LEAVES IN SILKWORM Bombyx mori L. DURING THE PROGRESS OF ENTOMO-PATHOGENIC FUNGUS Beauveria bassiana (Bal) Vuill.

Silkworm Bombyx mori is an economically important monophagous insect which is thoroughly domesticated by providing all the requisites for its growth and survival. Due to domestication over centuries, silkworms have become very gentle and delicate to the environmental conditions and different types of micro-pathological agents. The microorganisms such as virus, bacteria, fungi and protozoa cause diseases such as grasserie, flacherie, muscardine and pebrine which are the major threat to the sericulture industry. Chandrasekaran and Nataraju [1] stated that, out of the total crop loss due to different diseases, 10 to 40 per cent of crop loss occurs due to fungi, Beauveria bassiana in India. Nutrition is the basic unit of silkworm growth and development. Feeding and conversion efficiency of mulberry leaves such as leaf to cocoon ratio, leaf to shell ratio etc., in silkworm is one of the commercially important factors to obtain good dividends. Silkworm acquires its essential nutrients and water from the mulberry leaves it consumes. Various nutritional parameters such as ingestion of mulberry leaf, digestion, Efficiency of Conversion of Ingesta to Larva, Efficiency of Conversion of Digesta to Larva, Efficiency of Conversion of Ingesta to Cocoon, Efficiency of Conversion of Digesta to Cocoon, Efficiency of Conversion of Ingesta to Shell, Efficiency of Conversion of Digesta to Shell, I/g- Cocoon, D/g- Cocoon, I/g-Shell, D/g-Shell were estimated in the present investigation in Beauveria bassiana infected silkworms compared to untreated silkworms to understand the conversion efficiencies in infected silkworms. The results indicated a drop in ingesta, digesta, conversion efficiencies of ingesta and digesta to larva, cocoon and shell in the inoculated silkworms. On the contrary, ingesta and digesta required to produce one gram cocoon and one gram shell was higher in inoculated silkworms than in healthy silkworms. So, there is need to understand the various mechanisms involved and physiological changes occurring in the silkworm due to diseases which may be useful in developing prophylactic measures to overcome the attack of diseases.

Genetics, Mechanisms and Deployment of Brown Planthopper Resistance Genes in Rice

Among the rice insects, brown planthopper (BPH), (Nilaparvata lugens Stål) is a monophagous migratory phloem-sucking insect causing severe loss in Asiatic countries. High nitrogen and willful insecticide application coupled with an increase in temperature have created havoc by this pest during the last few years in certain parts of India, Indonesia, China, Japan, Taiwan, Vietnam, and the Philippines. Though chemical control measures are advocated to mitigate this insect, yet, the incorporation of host-plant resistance factor is the preferred approach to manage this insect attack owing to the high cost of chemical control and adverse effects on the environment. To date, more than 40 major resistance genes and 22 minor genes or quantitative trait loci (QTLs) are identified. Cloning of 11 BPH resistance genes has been completed to date. Majority of the cloned genes produced coiled-coil nucleotide-binding and leucine-rich repeat protein for the defense response in the host plant. Salicylic acid, jasmonic acid, ethylene, mitogen-activated protein kinases, Ca2+, OsRac1, and other signaling molecules play a definite role in the defense response. Signal transduction may lead to sieve tube sealing, production of metabolites, and induction of proteinase inhibitor for defense response against BPH attack. Plants have intrinsic mechanisms for recognition of damage-associated and herbivore-associated molecular patterns and elicitors for host defense response. This review provides an update on the sources of resistance, identification of resistance genes, gene maps, (QTL) detection, cloning, insights into the molecular mechanisms of resistance, and deployment of resistance genes for durable and broad-spectrum resistance in the cultivars against BPH.

EVALUATION OF PESTICIDES TO CONTROL MANGO STONE WEEVIL (Sternochetus Mangiferae; Fabricius; Coleopter: Curculionidae) IN EASTERN TERAI OF NEPAL

Mango, Mangifera indica (L.) is the important fruit crop in production in Nepal. Sternochetus mangiferae; Fabricius (Coleoptera: Curculionidae) is major monophagous insect pest which causes loss of both quantitative and qualitative value. To mitigate this problem, we designed and conducted experiment in Randomized Complete Block Design to evaluate effective insecticide against mango stone weevil on station and farmers orchard in two consecutive years at Sunsari and Udaipur districts. We sprayed five insecticides namely: azadirachtin, thiamethoxam, flubendiamide, lamda cyhalothrin and dimethoate in recommended doses on mango plant when the fruit was of pea size for four times at ten days interval. The damage was recorded at harvesting stage. Significantly less damage was recorded on the thiamethoxam treated plants followed by flubendiamide and lamda cyhalothirn. The interaction of the treatments with the location and years was not significantly different suggesting that the year and location had not any influence on the treatment effect. Our result suggested that thiamethoxam is effective to manage mango stone weevil.

Effect of major pollutants from motor vehicles on mulberry leaves and food ingestion, assimilation conservation efficiency of mulberry silkworm, Bombyx mori Linn.

The present investigation was carried out to ascertain the possible effect of feeding the silkworm, Bombyx mori L. with motor vehicles major pollutant like volatile organic compound, nitrogen oxides, carbon monoxide, sulfur dioxide and green gases polluted mulberry leaves on the food consumption, assimilation and conversion efficiency using silkworm hybrids, SH6 × NB4D2, CSR2 × CSR4, DUN22 × DUN6 and CSR double hybrid in relation to the road pollutant from the National Highway at all over, India. The roads generate vast amount of pollutant which got deposited on the mulberry leaves. Silkworm is essentially monophagous insect feeds solely on mulberry leaves. Impact on the silkworm nutritional indices food consumption, assimilation and conversion efficiency were assessed by rearing the silkworm larvae on air polluted mulberry leaves besides the amount of pollutant deposition on the mulberry leaves was also measured. The food consumption, assimilation and conversion efficiency of the silkworm larvae got significantly reduced in both the IVth as well as in the Vth instar larvae, when they were fed with extreme polluted mulberry leaves as compared to those larvae which were fed with low polluted mulberry leaves. But the effect was more pronounced in the Vth instar as larvae utilize maximum amount of feed in the Vth instar. The reduced conversion efficiency culminated in the decreased average larval weight and average larval weight gain of the silkworm larvae and cocoon production. All the silkworm hybrids register a marked affect when they were fed with extreme polluted mulberry leaves, but CSR2 × CSR4 hybrid was affected most with the CSR double hybrid least affected.

​Insect Plant Interaction with Reference to Secondary Metabolites: A Review

Plant and herbivorous insect share a contradictory but everlasting relationship. To cope with the herbivores, plant invested its energy in the production of various defensive chemicals which are known as plant secondary metabolites (PSMs). During coevolution with plants, insects also adapted themselves to counter plant defensive mechanisms. The secreted saliva and ovipositional fluids of insects induce the production of secondary metabolites in plants. Plants also produce compounds constitutively in the tissues that are susceptible to insect attack. These compounds reduce insect growth and development of insects through interfering with the developmental phases, acting as feeding deterrent, reducing nutritive value, affecting protein digestion and the production of substances toxic to them. On the contrary, insect’s adaptations to PSMs include the detoxification of plant toxins, conversion of the toxic compounds into conducible form for its growth and development, development of feeding choice based on the concentration of PSMs, quicker absorption and elimination as feces and obtaining the help of symbiotic intestinal microorganism to inactivate toxic materials. Furthermore, insects also utilize PSMs as chemical cues mediated through their chemoreceptive systems. The selection of host plants by monophagous insect is sometimes concentrated on the production of particular PSMs. Secondary metabolites also act as attractant to insect pollinators by exhibiting distinctive odors. Insects also store toxic PSMs which are used by them against their predators and in giving protection to eggs. However, this intrinsic capability of plants to produce defensive chemicals in response to insect attack should be explored to a wide extent to optimize the performance of PSMs.

Comparative transcriptomics of leaves of five mulberry accessions and cataloguing structural and expression variants for future prospects.

Bombyx mori, a monophagous insect, prefers leaves of the certain species of Morus more than others. The preference has been attributed to morphological and anatomical features and biochemical compounds. In the present manuscript a comparison has been made among the transcriptome of leaves of the two preferred cultivated varieties and three wild types species. While assembling, high quality transcriptomes of five genotypes were constructed with a total of 100930, 151245, 89724, 181761 and 102908 transcripts from ML, MN, MS, K2 and V1 samples respectively. Further, to compare them, orthologs were identified from these assembled transcriptome. A total of 22462, 23413, 23685, 24371, 18362, 22326, 20058, 18049, 17567 and 20518 clusters of orthologs were found in one to one comparison in KvsN, KvsL, KvsS, KvsV, LvsN, LvsS, LvsV, NvsS, NvsV, and SvsV respectively. 4236 orthologs with algebraic connectivity of 1.0 were then used to compare and to find out differentially expressed transcripts from all the genotypes. A total of 1037 transcripts expressed that include some of the important morphology, anatomy and biochemical pathways regulating transcription factors (AP2/ERFs and C2H2 Zinc fingers) and signalling components were identified to express differentially. Further, these transcriptomes were used find out markers (SSR) and variants and a total of 1101013, 537245, 970877, 310437, 675772, 338400, 581189, 751477, 514999 and 257107 variants including SNP, MNP, Insertions and deletions were found in one to one comparisons. Taken together, our data could be highly useful for mulberry community worldwide as it could be utilized in mulberry breeding programs.

The Draft Genome of Yellow Stem Borer, an Agriculturally Important Pest, Provides Molecular Insights into Its Biology, Development and Specificity Towards Rice for Infestation.

Yellow stem borer (YSB), Scirpophaga incertulas (Walker) (Lepidoptera: Crambidae), a major monophagous insect pest of rice, causes significant yield losses. The rice-YSB interaction is very dynamic, making it difficult for management. The development of resistant lines has been unsuccessful as there are no effective resistant sources in the germplasm. Genome information is necessary for a better understanding of interaction with rice in terms of its recognition, response, and infestation mechanism. The draft genome of YSB is predicted to have 46,057 genes with an estimated size of 308 Mb, being correlated with the flow cytometry analysis. The existence of complex metabolic mechanisms and genes related to specific behavior was identified, being conditioned by a higher level of regulation. We deciphered the possible visual, olfactory, and gustatory mechanisms responsible for its evolution as a monophagous pest. Comparative genomic analysis revealed that YSB is unique in the way it has evolved. The obvious presence of high-immunity-related genes, well-developed RNAi machinery, and diverse effectors provides a means for developing genomic tools for its management. The identified 21,696 SSR markers can be utilized for diversity analysis of populations across the rice-growing regions. We present the first draft genome of YSB. The information emanated paves a way for biologists to design novel pest management strategies as well as for the industry to design new classes of safer and specific insecticide molecules.

Mild Abiotic Stress Affects Development and Stimulates Hormesis of Hemp Aphid Phorodon cannabis.

Simple SummaryFor centuries, hemp has been used by humans as a source of natural fiber. Nowadays, it is a multipurpose crop with many uses, but the most valuable are hemp metabolites including terpenes and cannabinoids. During the cultivation of hemp, farmers encounter wilting plants, inhabited by the hemp aphid—a persistent plant-damaging insect. The species lives mainly on the undersides of leaves and on flower stalks and feeds on the phloem sap. We studied the effects of temperature and the herbicide used by farmers in routine hemp cultivation on the population biology of hemp aphids. Hemp aphids thrived best at moderate temperatures between 20 and 25 °C. At this temperature range, they lived for about 25 days, during which they reproduced for 15 days, producing between 54.5 and 111.6 nymphs in total per female. At 28 °C, aphid survival and reproductive capacity were much lower. Treatment of plants with herbicide caused mild stress in aphids and resulted in increased aphid reproduction and a change in their behavior; aphids settled on lower parts of the plant rather than on the top part of the plant (growing point), which is normal in untreated plants. This new knowledge may help to manage the hemp aphid and reduce damage to hemp crops in the future.The hemp aphid Phorodon cannabis Passerini is a well- known (Asia, Europe) or newly emerging (North America) insect. It is a monophagous insect pest causing considerable damage in field and glasshouse cultivations. The aim of this work was to study the effects of meteorological (temperature) and agronomical (herbicide) factors on the biology of the hemp aphid. In one experiment, hemp plants were kept at constant temperatures ranging from 20 to 30 °C, and aphid survival and fecundity were measured. In a related experiment conducted at 20 °C, plants were treated with field-appropriate rates of a selective graminicide containing quizalofop-P-tefuryl (40 gL−1, 4.38%, HRAC group 1), commonly used to control weeds in hemp, and aphid enzyme activity was measured in addition to population parameters. We found that hemp aphids could live, feed and reproduce within the whole studied range of temperatures, demonstrating its great evolutionary plasticity. However, the optimal temperature for development was 25 °C, at which the insect lived and reproduced for 25 and 15 days, respectively, with an average fecundity of 7.5 nymphs per reproduction day. The herbicide treatment increased the activity of superoxide dismutase (SOD), catalase (CAT), β-glucosidase, S-glutathione transferase (GST), oxidoreductive peroxidase (POD), and polyphenol oxidase (PPO) in the aphids, but only on certain days after treatment, which indicates a mild stress in aphid tissues, related to a higher reproduction and changed feeding behavior; aphids moved from the actively growing tips compared to untreated plants. The results of these experiments are discussed in terms of the impact on the future management of this pest.

LIPARTHRUM COLCHICUMSEMENOV (COLEOPTERA CURCULIONIDAE SCOLYTINAE) IN ITALY: INTRODUCED, ESTABLISHED OR NATIVE SPECIES?

Liparthrum colchicumSemenov (Coleoptera Curculionidae Scolytinae) is a relatively unknown monophagous insect species primarily associated with thin dried twigs (about 0.5-1cm in diameter) of Laurel (Laurus nobilis). After being caught in traps located at Italian ports, it was initially considered an intercepted species alien to the country. However, recent findings, suggest that this beetle may have a different origin. Several records from different sites of Tuscany and Latium showed that it could be relatively widespread in Italy. These observations strengthened the hypothesis that this scolytid, harmless to L. nobilis, might be already established or even native to the country. Therefore, we argue that it could have been easily overlooked thus far, as it thrives only in twigs already wilted due to different environmental factors. Moreover, field observations, carried out in the two Italian Regions, evidenced high frequencies of its infestations in Laurel twigs previously colonized by Xylosandrus compactus. Notes on the taxonomy and biology of this species are also reported in the present wo

The therapeutic potential and the health benefits of Morus indica Linn.: a mini review

Morus indica (L.) commonly known as Indian mulberry belonging to the family Moraceae is a fast growing perennial plant and is the primary food plant for the monophagous insect Bombyx mori has a special significance in the sericulture industry. Medicinal properties of this plant have been depicted in the ancient literature of Ayurveda. Some of the ayurvedic preparations use fruits, leaves, roots, bark or latex of the mulberry plant as potential treatment aid against various diseases. Because of the presence of several bioactive compounds like steroids, phenolics, alkaloids, reducing sugars, tannins, flavonoids, anthocyanins, terpenoids, cardiac glycosides, saponins, proteins, amino acids, carbohydrates etc., it is traditional being used as natural medicine for- anti-bacterial, anti-fugal, anti-hyperglycaemic, anti-hypoglycaemic, anti-hypolipidemic, hepatoprotective, anti-diabetic, anti-cancer, anti-pyretic, high antioxidant, and anti-inflammatory properties. The present review reveals the wide range of important uses of Indian mulberry including its phytochemical composition, antioxidants and medicinal properties and management towards human diseases.

Growth rate pattern and economic traits of silkworm, (Bombyx mori L.) under the influence of inorganic and organic supplementation diet

The growth and development of silkworm larvae and subsequently cocoon productions are greatly influenced by mulberry leaves quality. Nearly 70 per cent of the silk produced is directly derived from mulberry leaf proteins. Hence, silkworm should be fed abundantly with good quality mulberry leaves for the successful cocoon production and high yield of silk. Silkworm is a monophagous insect which feeds only on mulberry leaves. Nutrition improves the growth, development, health, feed consumption and conversion of silkworm thereby improving the economical traits. The present study deals with the supplementation of Inorganic and Organic diet for the growth and development of double strains (FC1 × FC2). Oral supplementation of inorganic tissue salt and organic nutrients. The economic performance of double strains (FC1 × FC2) evaluated based on larval, cocoon, pupa shell weights and Av. shell ratio % relationship of food consumption to larval weight, cocoon weight shell weight, Av. Shell ratio % etc. The observed parameters showed improvement in inorganic and organic when compared to the respective control.

NADPH Oxidase 5 Is Essential for Molting and Oviposition in a Rice Planthopper Nilaparvata lugens.

Simple SummaryThe brown planthopper, Nilaparvata lugens, a plant phloem-sucking Hemipteran insect, has become the most destructive pest for rice—the major food source for half of the world’s population. Nilaparvata lugens possess robust fecundity, enabling population densities to increase quickly in a favorable environment. Nilaparvata lugens has also been used as a model system for ecological studies and for developing effective pest management. To better understand the regulation mechanisms of insect reproduction and to provide insights to improve pest control, we searched N. lugens genome and transcriptome databases and identified an NADPH oxidase 5 gene, which was specifically expressed in ovaries of female adults and freshly laid eggs in rice leaf sheaths. Although homologous NADPH oxidase 5 genes have been identified in many insect species, their reproductive functions remain unknown. In this work, our findings initially reveal a functional role of the NADPH oxidase 5 gene in molting and oviposition in N. lugens. This novel finding improves our understanding of the reproductive strategies in insects and provides a potential molecular target for effective pest control of the rice planthopper.The brown planthopper Nilaparvata lugens is a typical monophagous insect herbivore that feeds exclusively on rice sap. This insect pest causes serious damage to rice crops throughout East Asian countries. Chemical control remains the first choice for managing N. lugens populations; however, the use of insecticides has given rise to planthopper resurgence and additional environmental risks. Nilaparvata lugens is a model insect of Hemiptera because its whole genome sequence has been elucidated and is susceptible to RNA interference. In this study, our findings revealed that a superoxide-generating gene, NADPH oxidase 5 (Nox5), is essential for molting and oviposition in a Hemipteran insect Nilaparvata lugens. Knockdown of Nox5 transcript levels by RNA interference in 2nd–5th-instar nymphs results in significantly lethal deficits in the molting transitions from nymph–nymph and nymph–adult. Nox5 knockdown leads to a reduction of hydrogen peroxide in female ovaries and failure of oviposition from the insect ovipositor into the rice leaf sheath. Here, we provide in vivo evidence demonstrating that Nox5 is a key enzyme for regulating molting and oviposition in this insect species.