Live Larvae Research Articles

Competitive interactions for food resources between invasive Ponto-Caspian gobies and their native competitors in the context of global warming

Climate warming can modify the process of biological invasions by affecting the outcomes of competition between alien species and their native counterparts in invaded environments. Inland freshwaters are particularly vulnerable to the intensification of such phenomena due to the accumulation of invaders, including thermophilic species that may benefit from warming. We intended to check whether an elevated summer temperature (25 vs. 17 °C) affects the abilities of the Ponto-Caspian gobies to compete for food. These fish are considered temperature-tolerant, highly invasive freshwater fish in Europe. In laboratory experiments, we tested single- and two-species pairs of juvenile specimens of two goby species and their native counterparts from the same ecological guild (the racer goby Babka gymnotrachelus versus European bullhead Cottus gobio, and monkey goby Neogobius fluviatilis versus native gudgeon Gobio gobio). The fish competed for food (live chironomidae larvae provided at rates below satiation) for 1 hour at night. We analysed behaviours associated with direct interactions (aggression acts) and foraging activity (time to enter the feeder and the time spent in the feeder). We found that although the gobies did not show higher aggression than the natives, they more actively accessed food compared to the latter, irrespective of temperature. Our results suggest that, in the wild, the invasive fish have a competitive advantage over the native ones due to better resource allocation (gaining food without incurring the costs of aggression) and will maintain this advantage as water warming continues.

Efficacy of Larval Therapy for Wounds: A Systematic Review and Meta-Analysis.

Background/Objective: Larval therapy (LT), an intervention using live fly larvae to remove necrotic tissue and promote healing, has regained attention in order to address the growing need for chronic wound management. LT was approved by the Food and Drug Administration (FDA) in 2004 to treat difficult-to-heal wounds; however, LT remains an underutilized therapy. To evaluate efficacy of LT in a systematic review and meta-analysis of wound outcomes from randomized controlled trials (RCTs). Methods: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to conduct a literature search across five databases for published and unpublished RCTs comparing LT to conventional therapy. A meta-analysis was performed to evaluate LT's effect on debridement as the primary outcome. Wound healing, bioburden, and treatment-related pain were analyzed as secondary outcomes. Bias was assessed using Cochrane's Risk-of-Bias 2 tool. Results: Eight RCTs were included in the review. The meta-analysis suggested that LT may be more effective for complete wound debridement (RR = 2.17), though this result was not significant (p = 0.09). The analysis is limited by the small number of studies and the high heterogeneity between studies (I2 = 75%). There were no significant differences in the healing rate, antimicrobial effects, or pain compared to conventional therapy. There is a moderate risk for bias in the selection of reported outcomes. Conclusions: LT is as effective as conventional therapy for debridement and may be an alternative for patients who cannot tolerate traditional methods. LT patients may experience similar levels of pain, but LT does not worsen wound healing or infection compared to those receiving routine care.

Black soldier fly larvae: a one health approach to investigate gut, and organ health and meat quality response in slow-growing chickens

BackgroundThe inclusion of sustainable protein sources in poultry feed has become essential for improving animal welfare in livestock production. Black soldier fly larvae are a promising solution due to their high protein content and sustainable production. However, most research has focused on fast-growing poultry breeds, while the effects on native breeds, such as the Bianca di Saluzzo, are less explored. This study aimed to evaluate the impact of BSFL supplementation in the diet of slow-growing chickens, with a focus on growth, intestinal health and meat quality for final consumers.ResultsThe study demonstrated that Black soldier fly larvae supplementation, both in dehydrated and live form, improved growth performance, with an increase in final weights compared to the control group. No significant differences were found in feed conversion ratio, liver and spleen weight or histomorphometry between groups. Black soldier fly larvae supplementation did not negatively affect immune function or liver metabolism. Higher production propionic acid was detected in the black soldier fly larvae fed groups compared to the control, suggesting an effect on volatile fatty acid production. Gut microbiota analysis showed an increase in beneficial bacteria, such as Faecalibacterium, in the live larvae group. Furthermore, the meat fatty acid profile and atherogenicity and thrombogenicity indices did not undergo significant changes, implying a low potential risk to consumers’ cardiovascular health.ConclusionsBlack soldier fly larvae supplementation in the diet of Bianca di Saluzzo improved growth without compromising animal health or meat quality. Moreover, the increase in beneficial volatile fatty acids and the modulation of gut microbiota suggest a positive impact on gut health. Finally, the absence of negative effects on meat lipid profiles confirms nutritional safety for consumers, making black soldier fly larvae a valid alternative in poultry feed. These results offer new perspectives for the use of Black soldier fly larvae in the nutrition of local breeds, contributing to sustainability in line with the One Health approach.

Perivascular Macrophages Convert Physical Wound Signals Into Rapid Vascular Responses.

Leukocytes detect distant wounds within seconds to minutes, which is essential for effective pathogen defense, tissue healing, and regeneration. Blood vessels must detect distant wounds just as rapidly to initiate local leukocyte extravasation, but the mechanism behind this immediate vascular response remains unclear. Using high-speed imaging of live zebrafish larvae, we investigated how blood vessels achieve rapid wound detection. We monitored two hallmark vascular responses: vessel dilation and serum exudation. Our experiments-including genetic, pharmacologic, and osmotic perturbations, along with chemogenetic leukocyte depletion-revealed that the cPla 2 nuclear shape sensing pathway in perivascular macrophages converts a fast (∼50 μm/s) osmotic wound signal into a vessel-permeabilizing, 5-lipoxygenase (Alox5a) derived lipid within seconds of injury. These findings demonstrate that perivascular macrophages act as physicochemical relays, bridging osmotic wound signals and vascular responses. By uncovering this novel type of communication, we provide new insights into the coordination of immune and vascular responses to injury.

Exploring the potential of black soldier fly live larvae as a sustainable protein source for laying hens: A comprehensive study on egg quality

Live insect larvae were recently proposed for use in laying hens in intensive chicken farming as an innovative form of environmental enrichment. This study aimed to evaluate the effect of laying hen age and feeding with live Black Soldier Fly larvae (BSFL) on egg quality attributes, i.e., chemical composition, fatty acid (FA) profile, and metabolic profile using nuclear magnetic resonance (NMR) spectroscopy. To this aim, 108 Lohman Brown hens were housed in 27 cages (9 replicates per treatment, 4 birds per pen) and monitored between 16 and 34 weeks of age. The hens were split into three experimental groups: a control group fed a commercial diet, and two experimental groups fed the same commercial diet plus 15% or 30% of live BSFL, as fed basis on the expected daily feed intake (DFI). The experimental treatments did not affect the egg and eggshell quality attributes. The supplementation with live BSFL did not influence the chemical composition in terms of macronutrients or the main NMR profiles of egg yolk and albumen. The FA profile of the egg yolk significantly changed as the eggs from hens fed BSFL presented higher rates of SFA and PUFA (P<0.05), lower rate of MUFA (P<0.001), and higher rates of C18:2n 6 (P<0.05) and C18:3 n3 compared to the control eggs (P<0.001). There were no significant differences in the ratio of n-6 to n-3 PUFA. The age of the hens strongly affected egg quality traits (P<0.001), mainly the egg weight, shell weight, shell thickness, eggshell-breaking strength, and eggshell redness (a*) and yellowness (b*), besides the metabolic profile of both egg yolk and albumen. Considering the interaction diet * age of hens, only a few significant effects occurred on egg quality attributes and FA profile. In conclusion, a supplementation with live BSFL up to 30% of DFI may be safely used in laying hen feeding without impairing egg quality.

Calcification in sea urchin larvae is associated with low metabolic costs.

The energetic costs to generate calcium carbonate skeletons and shells in marine organisms remain largely speculative due to the scarcity of empirical data. However, this information is critical to estimate energetic limitations of marine calcifiers that can explain their sensitivities to changes in sea water carbonate chemistry in past, present and future marine systems. The cost of calcification was evaluated using larval stages of the purple sea urchin, Strongylocentrotus purpuratus. We developed a skeleton re-mineralization assay, in which the skeleton was dissolved in live larvae followed by a re-mineralization over a few days. During skeleton re-mineralization, energetic costs were estimated through the measurement of key metabolic parameters including whole animal metabolic rates, citrate synthase (CS) enzyme activities and mRNA expression as well as mitochondrial densities in the calcifying primary mesenchyme cells (PMCs). Minor increases in a CS activity and a 10-15% increase in mitochondrial densities in PMCs were observed in re-mineralizing larvae as compared to control larvae. Re-mineralization under three different pH conditions (pH 8.1, pH 7.6 and pH 7.1) decreased with decreasing pH accompanied by pronounced increases in CS expression levels and increased mitochondrial densities in PMCs at pH 7.6. Despite a prominent increase in mitochondrial density of primary mesenchyme cells, particularly in the calcifying cohort of this cell type, this work demonstrated a low overall metabolic response to increased mineralization rates on the whole animal level under both, high and low pH conditions. We conclude that calcification in sea urchin larvae is compromised under low pH conditions, associated with low energetic efforts to fuel compensatory processes.

Image response-assisted volumetric reconstruction for simultaneous multi-color light-field microscopy.

Light-field microscopy enables real-time volumetric imaging, offering substantial advantages for real-time fluorescence imaging. However, when applied to multi-color imaging, positional cross-talk between different fluorescent signals in the object space reduces reconstruction accuracy. Additionally, imaging each color through sequential excitation of fluorophores significantly compromises imaging speed. In this paper, an image response-assisted volumetric reconstruction method that unmixes multi-color fluorescence light-field images using pixel support derived from the light-field imaging response is proposed. This approach enables simultaneous multi-color imaging with significantly improved volumetric reconstruction accuracy. The correctness and effectiveness of the proposed method are validated through both simulations and experiments. The root-mean-square-error of multi-color volumetric reconstruction is reduced by 37.87 % on average compared with the simultaneous multi-color reconstruction methods obtained by simply combining single-pixel spectrum conversion methods and linear unmixing method in rapid-moving micro-particle observation, showcasing high accuracy simultaneous multi-color imaging performance. Volumetric imaging of motor neurons and whole-body cells of live dual-color zebrafish larvae at 20 Hz demonstrates the ability to be applied to real biomedical imaging.

Live black soldier fly larvae as environmental enrichment for native chickens: implications for bird performance, welfare, and excreta microbiota

Dietary live insect larvae were recently proposed for use in laying hens and broiler−intensive chicken farming as an innovative form of environmental enrichment, but their use in native dual-purpose chickens has never been investigated. This study aims to evaluate the effects of live black soldier fly (BSF) larvae as environmental enrichment in two autochthonous dual-purpose chicken breeds, namely Bionda Piemontese (BP) and Bianca di Saluzzo (BS), in terms of bird performance, behaviour, integument status, excreta corticosterone metabolites (ECMs), and microbiota analyses. A total of 90 BP and 90 BS hens aged 308 days old were randomly distributed between two treatment groups (three replicates/group/breed, 15 hens/replicate). For the following 90 days, the control group (C) was fed a commercial feed only, whereas the BSF group was fed the commercial diet plus BSF live larvae calculated at 6% of the expected daily feed intake (DFI). Larva ingestion time, bird performance, integument scores, and behavioural observations were assessed at regular intervals, and excreta samples were collected to evaluate ECM and microbiota. The larva ingestion time became faster over the course of the experimental trial (P < 0.001). The DFI of BSF-fed hens was lower than that of C hens independently of breed (P < 0.001), whereas only in the BS hens, the live weight of the BSF-fed group was greater than that of the C group (P < 0.01). The BSF-fed BP hens showed a higher laying rate and feed conversion ratio compared with BSF-BS (P < 0.05). Better total integument scores were observed in BSF-fed BP hens compared with C-birds (P < 0.05). The BSF-fed hens displayed higher frequencies of preening, trotting, and wing flapping than C, as well as a lower incidence of severe feather pecking (P < 0.05). An increase in allopreening was only identified in BSF-fed BS hens with respect to the C hens (P < 0.001). No differences in ECM and faecal microbiota were observed between treatment groups. In conclusion, the administration of BSF live larvae as environmental enrichment has the potential to positively influence the welfare of both BP and BS chickens, by enhancing the frequency of positive behaviours whilst reducing severe feather pecking, without affecting their excreta microbiota. BSF larva administration also has the potential to improve the productive performance and the plumage status of the BP breed.

Performance, egg quality and organ traits of laying hens fed black soldier fly larvae products

Due to consumer demands and institutional pressure, the egg production sector, is looking for alternative protein sources for laying hen feed to support more sustainable, circular production. black soldier fly (BSF) larvae could be used as a protein source. In addition to protein the larvae contain large quantities of fat and can either be fed to laying hens unprocessed (alive) or processed (meal and oil). The current study was performed with 560 Brown Nick laying hens from 20 to 27 wk of age. The laying hens were divided over 5 treatments, each replicated 8 times. Treatments consisted of standard laying hen feed (control) and standard feed in which soybean meal was partly exchanged with live BSF larvae or BSF larvae meal and oil combined, at 2 inclusion levels. During the experiment production parameters, egg-quality, and length and weight of various organs were measured. Laying hens fed BSF larvae products consumed less feed compared to those of the control group. Most egg production parameters were similar, however laying hens fed diets with BSF larvae meal plus oil produced eggs with lower egg weight during the last 2 wk of the experiment, compared to the control group. All egg-quality characteristics remained the same across treatments, except for darker yolk colors when feeding BSF meal and oil and high inclusion of live BSF larvae. This is a favorable characteristic for European consumers. The weight of intestinal organs was largely unaffected by the treatments. The jejunum and ileum weight of laying hens fed live larvae was lower compared to the control group. As FCRs were similar or improved compared to the control group, we assume that nutrient utilization was not impaired. For most detected differences the type of BSF larvae product (live larvae or meal plus oil) rather than inclusion level was of significance.

Detecting Gaps in Knowledge: The Case of the Anisakis in Northwestern Spain

In the marine environment, fish parasites are present in most seafood species. The most common are nematodes of the genus Anisakis, which can parasitize human tissues, causing anisakiasis and allergies—in some cases with a strong reaction, such as anaphylactic shock. This happens when people ingest live or dead larvae present in the muscles or viscera of a wide range of fish and cephalopods. Consumer education has been positioned as one of the most effective alternatives for its prevention. This study, carried out in Asturias (northwest Spain), sought to identify the seafood products that present the greatest risk of anisakiasis for consumers, taking into account their consumption, the prevalence of Anisakis, and consumer knowledge about this parasitosis. In the results, hake (Merluccius merluccius) and cod (Gadus morhua), frequently consumed in the region and with high parasite prevalence, do not pose a great risk because they are consumed when well cooked. Instead, sardine (Sardina pilchardus), highly consumed and less parasitized, and anchovy (Engraulis encrasicolus), highly parasitized and less consumed, would exhibit a medium risk. Young participants know more about the risks of anisakiasis from raw seafood. The gaps detected in the knowledge about the ability of temperature treatments to eliminate parasites, especially in allergic people, must be addressed for better prevention. We suggest campaigns adapted to the population sectors.

Multiplexed In Vivo Imaging with Fluorescence Lifetime-Modulating Tags.

Fluorescence lifetime imaging microscopy (FLIM) opens new dimensions for highly multiplexed imaging in live cells and organisms using differences in fluorescence lifetime to distinguish spectrally identical fluorescent probes. Here, a set of fluorescence-activating and absorption-shifting tags (FASTs) capable of modulating the fluorescence lifetime of embedded fluorogenic 4-hydroxybenzylidene rhodanine (HBR) derivatives is described. It is shown that changes in the FAST protein sequence can vary the local environment of the chromophore and lead to significant changes in fluorescence lifetime. These fluorescence lifetime-modulating tags enable multiplexed imaging of up to three targets in one spectral channel using a single HBR derivative in live cells and live zebrafish larvae. The combination of fluorescence lifetime multiplexing with spectral multiplexing allows to successfully image six targets in live cells, opening great prospects for multicolor fluorescence lifetime multiplexing.

Dehydrated and live black soldier fly larvae as environmental enrichment in indigenous slow-growing chickens: performance, gut health, and chitinolytic enzyme activity

The demand for sustainable and ethically farmed animal products is on the rise as consumers become more environmentally and animal welfare conscious. The need to diminish the consumption of soybean meal is urgent, and companies are looking for ways to respond to this necessity by looking for alternatives to soybean meal. This study assessed the impact of introducing whole dehydrated and live black soldier fly larvae (BSFL) into the diet of an indigenous chicken breed as environmental enrichment. A total of 144 39-day-old male Bianca di Saluzzo chickens were distributed among 18 pens and assigned to three different experimental groups. The control group received a diet where soybean meal was entirely replaced by alternative ingredients. The two experimental groups were given the same diet supplemented with 5% of the expected daily feed intake of whole dehydrated BSFL or whole live BSFL. Throughout the trial period (from the bird age of 39–174 days of age), live weight was recorded every 21 days, and the average daily gain, daily feed intake, and feed conversion ratio were calculated. The time required for the birds to consume the larvae was recorded three times a week. At age 147 and 174 days, 12 birds per treatment were selected based on mean live weight and slaughtered. Measurements included hot and chilled carcass weights, organ weights (spleen, liver, heart, stomach), breast and thigh muscle weights, and the corresponding yields were calculated. Acid protease activity was measured in proventriculus extract, and chitinase and chitosanase activity was calculated based on the release of reducing sugars from chitin or chitosan. The results showed little improvement in final live weights and daily feed intakes of the animals fed the insect larvae compared with control birds. Larva supplementation had no negative impact on the overall well-being of the animals assessed by blood analysis and histopathological assessment of the intestinal tract, spleen, and liver. No differences were found between the dehydrated vs live insect larvae consumption times, with all larvae being eaten up very rapidly (< 3 min). The birds fed BSFL showed an increase in chitinase activity. These findings support the potential use of whole BSFL as a form of environmental enrichment, particularly in their dehydrated form, being more convenient to use and store, which would also encourage the uptake of this practice by farmers.

Morphometric features of larvae of the mussel Mytilus galloprovincialis (Lamarck, 1819) (Bivalvia: Mytilidae) in ontogenesis

Sequentially appearing in ontogenesis, the morphometric features of mussel Mytilus galloprovincialis larvae can serve as a basis for their species identification among the pool of larvae of other bivalve mollusc species found in the Black Sea plankton. The study presents the photographs of live mussel larvae and scanning electron microscope (SEM) images of the larvae hinge at different developmental stages: D-veliger, veliger, veliconcha and pediveliger. There was shown the sequence of morphological changes in provinculum, as well as the shell’s size and shape changes, from the earliest straight-hinge stage of veliger up to metamorphosis. The correlation between shell width (C, µm) and shell length (L, µm) [ ; R2 = 0.9879], as well as the correlation between hinge edge length (l, µm) and shell length (L, µm) [ ; R2 = 0.9872] were determined for mussel larvae ranging in size from 98 to 350 µm. By employing energy dispersive X-ray spectroscopy EDS(x), the elemental composition of the larvae shell’s hinge edge at the stages of veliger, veliconcha and pediveliger was determined; and it showed the presence of calcium, carbon, oxygen, sodium and chlorine. Magnesium was detected in pediveligers’ hinge edge only.

Bacillus thuringiensis serovar morrisoni biovar tenebrionis impact and persistence in Tenebrio molitor larvae

Abstract The yellow mealworm (Tenebrio molitor L.; Coleoptera: Tenebrionidae) has been proposed during the last decade as a suitable insect species for feed and food production. The inclusion of by- and side-products of cereal and vegetable production in the feed of yellow mealworm increases the probability of exposure to Bacillus thuringiensis sv. morrisoni biovar tenebrionis (Btt), an entomopathogen used in the biological control of coleopteran pest species. The lack of studies on effects of Btt spores and toxin on T. molitor in mass-rearing systems led us to explore its effect on survival and growth of larvae and its persistence in larvae and in frass. Larvae of different body weight (3, 5, 10 and 40 mg) were exposed by free feeding for 72 hours to a range of Btt spore – crystal concentrations spiked to wheat bran (WB). Susceptibility to the entomopathogen was concentration-dependent and linked to the larval body weight, larvae of higher weight being less susceptible. Growth and feed conversion ratio of survivors showed significant impact for low-weight larvae while less or no effect was recorded for larvae having higher weight. Btt was still recovered from larvae and frass 14 days after feeding with non-contaminated WB, indicating a certain level of persistence in the tested conditions, on alive 40-mg larvae, implying a potential risk in T. molitor mass rearing.

A microfluidic chip for immobilization and imaging of Ciona intestinalis larvae.

Sea squirts (Tunicata) are chordates and develop a swimming larva with a small and defined number of individually identifiable cells. This offers the prospect of connecting specific stimuli to behavioral output and characterizing the neural activity that links these together. Here, we describe the development of a microfluidic chip that allows live larvae of the sea squirt Ciona intestinalis to be immobilized and recorded. By generating transgenic larvae expressing GCaAMP6m in defined cells, we show that calcium ion levels can be recorded from immobilized larvae, while microfluidic control allows larvae to be exposed to specific waterborne stimuli. We trial this on sea water carrying increased levels of carbon dioxide, providing evidence that larvae can sense this gas.

Insect live larvae as a new nutritional model in duck: effects on gut health

BackgroundThis study aimed to evaluate the effects of Hermetia illucens (Black soldier fly-BSF) and Tenebrio molitor (Yellow mealworm-YMW) live larvae as a new nutritional model on duck’s gut health, considering gut histomorphometry, mucin composition, cytokines transcription levels, and microbiota. A total of 126, 3-days-old, females Muscovy ducks were randomly allotted to three dietary treatments (6 replicates/treatment, 7 birds/pen): (i) C: basal diet; (ii) BSF: C + BSF live larvae; (iii) YMW: C + YMW live larvae. BSF and YMW live larvae were administered on top of the basal diet, based on the 5% of the expected daily feed intake. The live weight, average daily gain, average daily feed intake and feed conversion ratio were evaluated for the whole experimental period. On day 52, 12 ducks/treatment (2 birds/replicate) were slaughtered and samples of duodenum, jejunum, ileum, spleen, liver, thymus and bursa of Fabricius were collected for histomorphometry. Mucin composition was evaluated in the small intestine through histochemical staining while jejunal MUC-2 and cytokines transcription levels were evaluated by rt-qPCR. Cecal microbiota was also analyzed by means of 16 S rRNA gene sequencing.ResultsBirds’ growth performance and histomorphometry were not influenced by diet, with a proximo-distal decreasing gradient from duodenum to ileum (p < 0.001), respecting the physiological gut development. Mucin staining intensity and MUC-2 gene expression did not vary among dietary treatments, even though mucin intensity increased from duodenum to ileum, according to normal gut mucus physiology (p < 0.001). Regarding local immune response, IL-6 was higher in YMW group when compared to the other groups (p = 0.009). Insect live larvae did not affect cecal microbiota diversity, but BSF and YMW groups showed a higher presence of Helicobacter, Elusimicrobium, and Succinatimonas and a lower abundance of Coriobacteriaceae and Phascolarctobacterium compared to C birds (p < 0.05).ConclusionsThe use of BSF and YMW live larvae as new nutritional model did not impair gut development and mucin composition of Muscovy ducks, but slightly improved the intestinal immune status and the microbiota composition by enhancing regulatory cytokine IL-6 and by increasing minor Operational Taxonomic Units (OTUs) involved in short-chain fatty acids production.

Lysin and Lytic Phages Reduce Vibrio Counts in Live Feed and Fish Larvae.

Vibrio species are naturally found in estuarine and marine ecosystems, but are also recognized as significant human enteropathogens, often linked to seafood-related illnesses. In aquaculture settings, Vibrio poses a substantial risk of infectious diseases, resulting in considerable stock losses and prompting the use of antimicrobials. However, this practice contributes to the proliferation of antimicrobial-resistant (AMR) bacteria and resistance genes. Our investigation aimed to explore the potential of biological agents such as bacteriophage CH20 and endolysin LysVPp1 in reducing Vibrio bacterial loads in both rotifer and fish larvae. LysVPp1's lytic activity was assessed by measuring absorbance reduction against various pathogenic Vibrio strains. Phage CH20 exhibited a limited host range, affecting only Vibrio alginolyticus GV09, a highly pathogenic strain. Both CH20 and LysVPp1 were evaluated for their effectiveness in reducing Vibrio load in rotifers or fish larvae through short-setting bioassays. Our results demonstrated the significant lytic effect of endolysin LysVPp1 on strains of Vibrio alginolyticus, Vibrio parahaemolyticus, and Vibrio splendidus. Furthermore, we have showcased the feasibility of reducing the load of pathogenic Vibrio in live feed and fish larvae by using a non-antibiotic-based approach, such as lytic phage and endolysin LysVPp1, thus contributing to the progress of a sustainable aquaculture from a One Health perspective.

THE EFFICACY OF DIFFERENT PESTICIDES FOR MANAGEMENT OF TOMATO LEAF MINER IN TOMATO AT GOKULESHWOR BAITADI

Tomatoes are an important produce in the Solanaceae family, and their productivity is heavily influenced by insect pests. Pesticide application is a common approach of pest management in Nepal’s local and large-scale vegetable farms. A field experiment was conducted using seven treatments, namely: T1 (Metarhizium anisopiliae at 2 g/liter), T2 (Neembicide at 5 ml/liter), T3 (Jholmol at 1:4 (Jholmol: water), T4 (Imidacloprid at 0.3 ml/liter), T5 (Control), T6 (Emamectin benzoate at 2 g/liter), and T7 (Chlorantraniliprole at 0.3 ml/liter) to control Tomato leaf miner. In a Randomized Complete Block Design (RCBD), these treatments were replicated three times in the field of Gokuleshwor Agriculture and Animal Science College in Gokuleshwor, Baitadi. The effect of different treatments on the population of Tomato leaf miner was studied using the number of infested leaves per plant, the number of live larva per plant (leaves and buds), and the number of infested terminal buds per plant from four plants forsaking the corner plants in each plot. The study findings revealed that the Control had the maximum number of live larvae per plant as well as the lowest damage in Emamectin benzoate (0.16 per plant), followed by Chlorantraniliprole (0.33 per plant) and Neembicide (0.42 per plant). The highest number of infested leaves per plant was recorded in Control (3.25 per plant) and the lowest in Chlorantraniliprole (1.66 per plant), followed by Emamectin benzoate (1.86 per plant) and Neembicide (2.08 per plant). The number of infested terminal buds per plant was recorded as highest in Control (0.58 per plant) and lowest in Chlorantraniliprole (0.08 per plant), followed by Imidacloprid (0.25 per plant) and Emamectin benzoate (0.33 per plant). So for the management of tomato leaf miners, the insecticides Chlorantraniliprole and Emamectin benzoate would be the best alternatives.

Quantitative assessment and monitoring of microplastics and nanoplastics distributions and lipid metabolism in live zebrafish using hyperspectral stimulated Raman scattering microscopy

Microplastics (MP) and nanoplastics (NP) pollutions pose a rising environmental threat to humans and other living species, given their escalating presence in essential resources that living subjects ingest and/or inhale. Herein, to elucidate the potential health implications of MP/NP, we report for the first time by using label-free hyperspectral stimulated Raman scattering (SRS) imaging technique developed to quantitatively monitor the bioaccumulation and metabolic toxicity of MP/NP within live zebrafish larvae during their early developmental stages. Zebrafish embryos are exposed to environmentally related concentrations (3–60 μg/ml) of polystyrene (PS) beads with two typical sizes (2 μm and 50 nm). Zebrafish are administered isotope-tagged fatty acids through microinjection and dietary intake for in vivo tracking of lipid metabolism dynamics. In vivo 3D quantitative vibrational imaging of PS beads and intrinsic biomolecules across key zebrafish organs reveals that gut and liver are the primary target organs of MP/NP, while only 50 nm PS beads readily aggregate and adhere to the brain and blood vessels. The 50 nm PS beads are also found to induce more pronounced hepatic inflammatory response compared to 2 μm counterparts, characterized by increased biogenesis of lipid droplets and upregulation of arachidonic acid detected in zebrafish liver. Furthermore, Raman-tagged SRS imaging of fatty acids uncovers that MP/NP exposure significantly reduces yolk lipid utilization and promotes dietary lipid storage in zebrafish, possibly associated with developmental delays and more pronounced food dilution effects in zebrafish larvae exposed to 2 μm PS beads. The hyperspectral SRS imaging in this work shows that MP/NP exposure perturbs the development and lipid metabolism in zebrafish larvae, furthering the understanding of MP/NP ingestions and consequent toxicity in different organs in living species.

Location and elimination of Anisakis simplex third stage larvae in Atlantic herring Clupea harengus L

We here describe the location of anisakid third stage larvae in Atlantic herring Clupea harengus L. caught in the North Sea in August 2023. We further demonstrate how industrial processing (mechanical gutting, removal of entrails, head, tail, hypaxial anterior musculature and vertebral column) reduces the overall infection and worm load in the musculature. The isolated anisakid larvae were identified as Anisakis simplex sensu stricto by a combination of morphometrics and molecular methods (PCR of rDNA and mtDNA, sequencing, BLAST analysis). As a baseline we examined a total of 75 specimens of freshly caught and ungutted herring and showed a positive correlation between host size (fish length and weight) and infection level. The overall prevalence of infection was 84 %, the mean intensity 11.3 (range 1–38 parasites per fish) and the abundance 9.52. The main part of the overall worm population was associated with stomach and pyloric caeca in the body cavity (77 %) and only 5 % was found in the musculature. Larvae occurred in the hypaxial part of the musculature (21), the epaxial part (7 worms) and the caudal part (5 worms). The prevalence of muscle infection was 28 % and the mean intensity 1.6 (range 1–5) parasites per fish and abundance 0.44 parasites per fish. In order to assess the effect of industrial processing on worm occurrence in the fish we examined a total of 67 specimens of herring, from exactly the same batch, but following processing. This included removal of organs in the body cavity, cutting the lower part of the hypaxial segment but leaving the right and left musculature connected by dorsal connective tissue. Five out of these fish carried one larva (prevalence 7.5%, mean intensity 1, abundance 0.07 larvae per fish), and these worms were located in the ventral part of the anterior musculature (2), in the central part of the anterior musculature (2) and one larva in the central part of the caudal musculature. The industrial processing reduced the overall occurrence (abundance) of worms in the fish from 9.52 to 0.07 (136 times reduction) and the occurrence in the musculature from 0.44 to 0.07 (6.28 times reduction). The overall prevalence was reduced from 84 % to 7.5 % (11.2 times reduction). Muscle infection prevalence fell from 28 % to 7.5 % (3.7 times reduction). We then followed another batch of herring following a marinating process (11% NaCl for 24 h and subsequent incubation in acetic acid and vinegar) by artificially digesting the flaps during week 1–8. Although a total of 31 larvae were recovered from 144 fish examined no live nematode larvae were isolated. The importance of fish handling, processing and marination for consumer safety is discussed.