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Background Culicoides insignis is a confirmed vector of bluetongue virus (BTV) throughout the American tropics and a possible vector of epizootic hemorrhagic disease virus (EHDV) in Florida. Despite its importance, fundamental information on the biology and ecology of this vector species is lacking. In this study, we examined the oviposition of C. insignis under laboratory conditions, monitored the development of immature stages and attempted colonization of this species. Methods Live C. insignis females were collected from the field using CDC-UV-LED traps, allowed to blood-feed on live chicken and given various natural substrates for oviposition in two-choice assays. The eggs deposited were transferred to 0.3% agar slants, and the hatched larvae were provided a diet of Panagrellus redivivus Linnaeus nematodes and the development of all immature stages was monitored. Results Culicoides insignis females exhibited an overall oviposition preference for dishes containing mud from their larval habitat as gravid females deposited a significantly higher number of eggs on these dishes (35.3 eggs/female) than on controls (17.7 eggs/female). The ovipositing females also deposited a higher percentage of eggs on substrates with habitat mud and other organically enriched muds (≥ 75.2%) compared to controls (31.0%). The larvae developed successfully to adulthood on the nematode diet, exhibiting high overall larval survival rates (85.0%). Sex ratios of the F1 generation were male biased, approximately 3:1 (male:female). Captive mating could not be induced in the F1 adults. Conclusions Mud from the larval habitat and other organically enriched muds provide strong oviposition cues to C. insignis under laboratory conditions. Further studies will be needed to identify the key biotic/abiotic factors influencing midge oviposition in the field. The agar/nematode method is effective for the rearing of C. insignis larvae. However, further studies will be needed to address the issue of male-biased sex ratios in the progeny and to examine the mating habits/cues of C. insignis in nature, which may provide clues towards inducing captive mating in the F1 adults. Graphical abstract

Major sperm proteins (MSPs) are a nematode-specific system of cytoskeletal proteins required for amoeboid sperm movement. A number of MSP genes vary in different nematode species, but encoded protein sequences reveal high homology between these proteins. However, all studies of MSP localization and functions to date are based exclusively on the representatives of the order Rhabditida belonging to the nematode class Chromadorea, while MSP-driven sperm movement in Enoplea, another major clade of the phylum Nematoda is still unconfirmed. In this study, we documented the presence of MSPs in the enoplean nematode Enoplus brevis (Bastian, 1865) (Enoplida) and compared MSP localization in sperm of this species with that of the chromadorean nematode Panagrellus redivivus (Linnaeus, 1767) (Rhabditida). Then, we analyzed the putative MSP sequences of both species. Our results indicate that MSPs are presented in E. brevis spermatozoa and form filamentous structures after sperm activation, which may be considered as the evidence of their motor functions similar to those in the spermatozoa of chromadorean nematodes. We found that E. brevis MSPs show lower homology to known proteins of rhabditids whose species exhibit hyper-conservatism in MSP protein sequences. These results reflect the more distant evolutionary relationships between Enoplea and Chromadorea than exist within Rhabditida order. Our data reveal a need to reevaluate current views of MSP evolution within Nematoda.

Chemical investigation on the cultures of the fungus Marasmius berteroi, resulted in the isolation of 10 compounds including 2 new ones named (S)-3,7-dihydroxy-1-indanone (1) and (S)-3-hydroxy-4-methoxy-3-methyl isobenzofuran-1(3H)-one (2). Their structures were determined based on NMR, HRESIMS and ECD spectra analysis. Compounds 5-6, 10 revealed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 95 %, 85 %, and 75 % at 2.5 mg/mL, respectively.

A new alkaloid named methyl 2-(3,4-dihydro-2H-pyrrol-5-yl)acetate (1), together with 24 known compounds, was isolated from the acetone extract of the fruiting bodies of Ramaria stricta. Their structures were elucidated on HR-ESI-MS and extensive 1D and 2D NMR spectroscopy. The nematocidal assay showed that three compounds, benzoic acid, 3-hydroxy-2-methylbenzaldehyde, and 4-(hydroxy)benzylbenzoic acid, exhibited a certain activity against Panagrellus redivivus.

To better understand the nanosize-relevant toxic effects and underlying mechanisms, N-acetylcysteine (NAC), as a mitigation agent, an ionic form of Zn (ZnCl2), and the binary mixture of ZnO with different particle sizes (15 nm and 140 nm), was used in toxicity assays with the nematode Panagrellus redivivus. The ZnCl2 concentrations were applied to show the amount of dissolved Zn ions present in the test system. Reactive oxygen species (ROS) measuring method was developed to fit the used test system. Our studies have shown that NAC can mitigate the toxic effects of both studied particle sizes. In the applied concentrations, ZnCl2 was less toxic than both of the ZnO particles. This finding indicates that not only ions and ROS produced by the dissolution are behind the toxic effects of the ZnO NPs, but also other particle size-dependent toxic effects, like the spontaneous ROS generation, are also relevant. When the two materials were applied in binary mixtures, the toxic effects increased significantly, and the dissolved zinc content and the ROS generation also increased. It is assumed that the chemical and physical properties of the materials have been mutually reinforcing to form a more reactive mixture that is more toxic to the P. redivivus test organism. Our findings demonstrate the importance of using mitigation agent and mixtures to evaluate the size-dependent toxicity of the ZnO. Graphical abstract

Larviculture is a critical period in the production of ornamental fish, due to the productive and nutritional needs of the larvae in the first days of life. The supply of live food is essential for the survival of the larvae, being Artemia sp. the most used food, although it represents a high cost. Making it necessary to search for lower cost live foods such as the nematode microworm. The present work was developed with the objective of evaluating, by means of growth, development and survival indices, the microverminal supply exclusively or associated to artemia and plankton for Betta splendens larvae. Larvae fed with microworm and artemia showed higher final weight, final length, length gain, higher rate of specific development and survival. The rate of uniformity in the treatment that received only microverm did not differ from the other treatments, however, the larvae submitted to the microworm and artemia diet showed a better uniformity rate when compared to those fed with microverm and plankton. The feeding strategy aimed at supplying microverm and artemia together promoted the best growth, development and survival rates in the initial Betta splendens larviculture. La larvicultura es un período crítico en la producción de peces ornamentales, debido a las necesidades productivas y nutricionales de las larvas en los primeros días de vida. El suministro de alimento vivo es fundamental para la supervivencia de las larvas y Artemia sp. el alimento más utilizado, aunque representa un alto costo. Haciendo necesaria la búsqueda de alimentos vivos de menor costo como el nematodo del microworm de la avena. El presente trabajo se desarrolló con el objetivo de evaluar, a través de índices de crecimiento, desarrollo y supervivencia, el aporte del microworm exclusivo o asociado al camarón de salmuera y plancton para larvas de Betta splendens. Las larvas alimentadas con microworm y camarones de salmuera tuvieron mayor peso final, longitud final, ganancia de longitud, mayor tasa de desarrollo específico y supervivencia. La tasa de uniformidad del lote en el tratamiento que recibió solo microworm no difirió de los otros tratamientos, sin embargo, las larvas alimentadas con microworm y camarón de salmuera mostraron una mejor tasa de uniformidad en comparación con aquellas alimentadas con microworm y plancton. La estrategia de alimentación con el objetivo de suministrar microworm y camarón de salmuera juntos promovió las mejores tasas de crecimiento, desarrollo y supervivencia en la larvicultura inicial de los peces ornamentales Betta splendens. A larvicultura é um período crítico na produção de peixes ornamentais, devido às necessidades produtivas e nutricionais das larvas nos primeiros dias de vida. O fornecimento de alimento vivo é essencial para a sobrevivência das larvas, sendo a Artemia sp. o alimento mais utilizando, apensar de representar custo elevado. Tornando necessária a busca por alimentos vivos de menor custo como o nematóide microverme da aveia. O presente trabalho foi desenvolvido com o objetivo de avaliar, por meio de índices de crescimento, desenvolvimento e sobrevivência, o fornecimento do microverme de forma exclusiva ou associado a artêmia e plâncton para larvas Betta splendens. As larvas alimentadas com microverme e artêmia apresentaram maior peso final, comprimento final, ganho em comprimento, maior taxa de desenvolvimento específico e sobrevivência. A taxa de uniformidade do lote no tratamento que recebeu apenas microverme não diferiu dos demais tratamentos, no entanto, as larvas submetidas ao regime alimentar com microverme e artêmia apresentaram melhor taxa de uniformidade quando comparas as que foram alimentadas com microverme e plâncton. A estratégia alimentar visando fornecer microverme e artêmia de forma conjunta promoveu os melhores índices de crescimento, desenvolvimento e sobrevivência na larvicultura inicial do peixe ornamental Betta splendens.

Laboratory rearing procedures of Culicoides stellifer Coquillett (Diptera: Ceratopogonidae) were evaluated with an aim towards colonization of this species. Eggs collected from field-collected gravid females were placed on 0.25% agar slants and given a diet of 1) nematodes (Panagrellus redivivus Linnaeus), 2) nematodes + lactalbumin and yeast (LY), 3) microbes from nematode medium, and 4) tap water (autoclaved). Complete larval development to adult stage occurred only in two treatments: 1) nematodes and 2) nematodes + LY. Culicoides stellifer larvae could not survive beyond 1 wk on a diet of microbes alone or in the sterile water treatment. Larval survival rates were high using nematode diet (79.2 ± 11.3% [mean ± SE]) but were slightly lower in the nematode + LY group (66.5 ± 19.6%). Larval stage lasted ~21 d in both treatments. Sex ratio of F1 adults was ~1:1 (M:F) using nematode diet but was male biased (~2:1) with nematode + LY diet. These findings collectively suggest that a microbial community is required for midge larvae, either to support invertebrate prey base or as a potential food source. But in the present study, the supplied microbes alone were not sufficient to support midge survival/development. It appears that other nutritional components may also be essential to support the larval survival/development of C. stellifer. Overall, a simple diet of bacterial feeding nematodes and their associated microorganisms can be used to rear C. stellifer larvae under laboratory conditions. However, captive mating in F1 adults poses a major obstacle for successful colonization of this species currently.

Bacillus thuringiensis is a gram-positive and spore-forming bacterium that synthesizes a wide diversity of proteins with insecticidal activity and which has demonstrated its potential and safety as a biocontrol agent for more than four decades. However, several susceptible insect species have been reported for evolving resistance, which demands screening for strains exhibiting novel insecticidal properties. In this work, we performed the genome sequence analysis and the insecticidal characterization of B. thuringiensis strain Bt-UNVM_94 isolated from Argentina. This strain produced quasi symmetric bipyramidal parasporal crystals as shown using Scanning Electron Microscopy. Its genomic sequence harbours one coding sequence showing homology to the crystal toxin Cry7Ga2 and another, with similarity to the Mpp2Aa3 (Mtx2) toxin. Known Cry7A and Cry7B are known to be active against some coleopteran and lepidopteran larvae, respectively. However, bioassays performed with spore-crystal mixtures of strain Bt-UNVM_94 exhibited dual toxicity with 50% and 91% mortality against Cydia pomonella (Lepidoptera: Tortricidae) and Anthonomus grandis (Coleoptera: Curculionidae), respectively. No toxicity was detected against the free-living nematode Panagrellus redivivus (Rhabditidae: Panagrolaimidae). This strain also showed no PCR amplification of the type I b-exotoxin thuE gene, consistent with the absence of mortality in b-exotoxin bioassays with Musca domestica (Diptera: Muscidae). Screenings of novel B. thuringiensis strains may provide toxins with novel insecticidal properties that can be used to suppress insect resistance to the most used B. thuringiensis-crops in the field.

Bacteria with nematicidal effects have attracted interest as biocontrol agents of pests and diseases due to their relatively low environmental impact compared to chemical management strategies1. The damage they cause to target nematodes is diverse and imperfectly understood4.Photorhabdus spp. (Enterobacteriaceae) lives symbiotically within the nematode Heterorhabditis spp. (Rhabditida: Heterorhabditidae). It is known that secondary metabolites of this gram-negative bacterium exhibit insecticidal activity, mainly in Lepidopteran and Coleopteran insects2. Studies have also shown that cell-free culture filtrates of Photorhabdus spp. have nematicidal activity on free-living nematodes and pest phytonematodes; however, the causes of death in these targets are still being studied. Fil: Salas, Augusto. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina Fil: Achinelly, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Sauka, Diego Herman. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Spent mushroom compost (SMC) is a residue generated in edible mushrooms production, such as Hypsizygus marmoreus. Its genome was recently sequenced, demonstrating cuticle-degrading protease genes. The present work aims to investigate the proteases from H. marmoreus spent mushroom compost (SMC) by verifying its action on nematode larvae. The extraction of the crude extract directly with water from H. marmoreus SMC proved to be efficient for proteases obtainment, with proteolytic activity of 195.36 ± 18.38 U g−1 of compound. Moreover, the zymogram and SDS-PAGE indicated the presence of two proteases with estimated molecular weights of 30.2 and 33.7 kDa. Due to the protease activity present in H. marmoreus SMC extract, there was a significant reduction in the number of Panagrellus redivivus and L3 in treated group compared to control group (p

Nematode-trapping fungi constitute a guild of species that develop specialized trapping structures with which they capture and digest nematodes. These traps are not constitutively present, but instead develop in the presence of nematodes ; they attract them , adhere to their cuticle and eventually pierce it, extending hyphae inside their bodies. Fil: Maestro, Mariano. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina Fil: Sauka, Diego Herman. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Microbiología y Zoología Agrícola; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentina

Comparative HPLC-PDA analyses of methanolic root extracts of the almost unstudied Chinese endemic species Stemona mairei, collected from nine locations throughout its natural habitat in northern Yunnan, led to the identification of the pyrrolo[1,2-α]azepine-type alkaloid protostemonine (1) as the main alkaloid and 3,4-dehydro-δ-tocopherol (9) as the main tocopherol derivative. Analysis of the five further Chinese Stemona species S. sessilifolia, S. japonica, S. parviflora and S. shandongensis, collected in adjacent locations, resulted in identification of eight Stemona alkaloids, with seven of them possibly derived from 1. Additionally, the presence of three tocopherols was confirmed co-chromatographically with authentic samples. From S. shandongensis, the alkaloids stemocochinin (7) and croomine (8) were isolated and their structures confirmed by NMR and MS analyses. Additionally, the quantitative content of protostemonine (1) and the tocopherols 9 and 10 present in extracts were assessed. Concerning the tocopherols, S. mairei differs by the occurrence of chromenol derivatives from the other species which accumulate both chromenol and chromanol derivatives. Furthermore, the root extracts of S. mairei exhibited nematicidal activities against Panagrellus redivivus. These results are briefly discussed in a biological and chemotaxonomic context, respectively.

Despite the increasing number and quantity of nanomaterials released in the environment, our knowledge on their bioavailability and possible toxicity to organisms is rather limited. Thus, we know quite little about sensitivity of various nematode feeding types and life strategies to treatments with nano metal oxides. The toxicity of zinc oxide nanoparticles (nano-ZnO) (with a particle size of 25 nm) and the bulk counterpart was investigated in two free-living nematode species of different life strategies: Xiphinema vuittenezi, a K-strategist plant-feeder nematode and Panagrellus redivivus, an r-strategist bacterivor nematode. The internal zinc concentration and the concentration of minor and trace elements were determined by total reflection X-ray fluorescence spectrometry. Concentration-dependent mortality in both nematode species was observed following a 24-h exposure both to nano-ZnO and bulk ZnO. The zinc concentration of the treating suspension had a significant effect on the internal zinc content of the animals in both cases. Particle size did not influence the internal zinc content. Our results show that nano and bulk ZnO have a similar dose-response effect on mortality of the bacterivor P. redivivus. In contrast, the nano-ZnO has stronger toxic effect on the mortality of X. vuittenezi. In general, X. vuittenezi did not react more sensitively to the treatments than P. redivivus, but appeared sensitive to the nano-ZnO treatment compared to bulk ZnO.

The toxic effects of zinc oxide (ZnO) nano- and non-nanoparticles on two species of soil organisms, the free-living nematode Panagrellus redivivus and the springtail Folsomia candida, were investigated. The toxicity of ZnO particles (with 15 and 140 nm average particle size) and ZnCl2 (used as a positive control for zinc ion dissolution) was tested in two different kinds of test media. Milli-Q water vs. soil solution was used for the tests involving P. redivivus, and plaster of paris vs. artificial soil for F. candida. For P. redivivus, application of the soil solution decreased the toxic effect. It is considered that this may be due to the less dissolved zinc ions, the organic matter content and ZnO aggregation. Furthermore, all of the compounds caused concentration-dependent mortality to the tested nematode species. In the tests with F. candida, the toxic effects of both ZnO and ZnCl2 were significantly lower in the tests involving plaster of paris. This could have resulted from the avoidance of the contaminated foods by the springtails. A decreasing effect on reproduction was observed only in the tests using artificial soil. Additionally, the ZnO particles of 140 nm significantly increased mortality in the soil solution test with P. redivivus and in the artificial soil in the tests with F. candida. Possibly, this is a consequence of a greater aggregation of the nanoparticle-sized ZnO at the end of the experiment, which resulted in a lower level of toxicity.

Colour production in fish is due mostly to food. In conditions of captivity, the type of food is restricted, while various types of food are used in aquaculture, from processed dry food to small aquatic animals. In this study, we used nauplii of Artemia franciscana, “water fleas” Moina wierzejski, micro-worm Panagrellus redivivus, and commercial flakes. We used Poecilia reticulata, which is one of the most traded fish in ornamental aquaculture and hypothesise that if the live food influences the coloration and growth of P. reticulata, there must be differences in the intensity of colour pattern and growth rate in fish fed with different living animals. Consistent with our prediction, females and males of P. reticulata were more colourful when they were fed on A. franciscana, P. redivivus and M. wierzejski than when they were fed commercial flakes. Females and males of P. reticulata fed with A. franciscana grew in less time than fish fed with P. redivivus, M. wierzejski, or commercial flakes. We conclude that live food is an excellent way to affect growth and coloration in fish.

This study assessed the performance of L. alexandri postlarvae (2 days after hatching) with different diets (Artemia and Panagrellus redivivus), food amounts (C300-C500-C700), and feeding frequencies (F1-F3-F6) in two experiments lasting 10 days. The best performing food type, Artemia and Artemia with P. redivivus, presented the highest survival rates as well as fish with the greatest weight, length, and specific growth rate (SGR). In the second experiment with Artemia, the weight, length, and SGR presented significant differences, increasing with higher amounts of prey. The best performance was obtained from a daily diet (F1) with the greatest amount of prey (C700).

In the present study, the nematicidal activity of an isolated strain of Mimosa pudica nodules was evaluated against the Nacobbus aberrans (J2) phytonymatodes with a mortality of 88.8%, while against the gastrointestinal nematode Haemonchus contortus (L3) and free-living Panagrellus redivivus was 100%. The ability to inhibit the growth of phytopathogenic fungi Fusarium sp., and Alternaria solani, as well as the oomycete Phytophthora capsici, this antifungal activity may be related to the ability to produce cellulases, siderophores and chitinases by this bacterial strain. Another important finding was the detection of plant growth promoter characteristics, such as auxin production and phosphate solubilization. The strain identified by sequences of the 16S and rpoB genes as Serratia sp. is genetically related to Serratia marcescens and Serratia nematodiphila. The promoter activity of plant growth, antifungal and nematicide of the Serratia sp. strain makes it an alternative for the biocontrol of fungi and nematodes that affect both the livestock and agricultural sectors, likewise, candidate as a growth-promoting bacterium.

The study was carried out on the local Amazon killifish from Pastaza basin high lands, genus Anablepsoides sp. in Ecuador. This specie is part of foothills freshwater ecosystems and due its attractiveness have, a potential for ornamental aquaculture, as an income option to small farmers. Actually does not known the demographic specie status in the wild. The aim of this initiative was to analyze the breeding development of Anablepsoides sp, with oat micro worms (Panagrellus redivivus) as live food source, in aquarium captivity. Methodologically five individuals were catch in the wild environment, in a Puyo river stream next to the Union Base community. The animals were maintained in a biotope aquarium, for 18 weeks, at 23,5°C, pH 7,3, with micro worms unique food supply, verifying their comfort and adaptability in these conditions. Biometrics measurements were realized and sexual maturity and behavioral observations were systematized trough ethogram for to descript their courtship process for breed. Results show that the Amazon killifish was adapted to the artificial biotope conditions, reflects for their individual size increase as standard length (SL) 4,40 ±0,55mm and total length (TL) 5,60±0,89. Was observed that the male is bigger in around SL 11,5mm and TL 15,50mm than the females, with maximums sizes in male SL 44mm and TL 52mm while females have SL 34mm and TL 39mm. The ethogram show that this is a diurnal specie. In the group analyzed, was identify a unique male that spends a lot of energy in the females persecution. Two females had an ambiguous behavior persecuting other females as male competition. Only one female had a spawning event and hatch two fry in captivity. The live food supply with P. redivivus thanks to their nutritional contents contribute adequately to the Anablepsoides sp, increasing their size and facilitating a breeding event, supporting their captivity life cycle adaptation.

This study assessed the feeding activity of the predatory nematode Butlerius butleri on the infective larvae of the sheep parasitic nematode Haemonchus contortus (Hc-L3) and on two free-living nematodes Panagrellus redivivus (Pr) and Rhabditis sp. (R) in sterile sheep faecal cultures. A bioassay was carried out in sheep faecal cultures, where predatory and prey nematodes were put together to assess the predatory behaviour on the different nematodes. Faecal cultures (n = 9) were set up in different treatments as follows: Treatments 1, 2 and 3 contained 20 specimens of B. butleri and 2000 Hc-L3, Pr and R, respectively; treatments 4, 5 and 6, contained only 2000 Hc-L3, Pr and R, respectively, as control groups. Treatment 7 contained 20 B. butleri as control. All treatments were incubated at room temperature for 30 days. The average number of nematodes recovered from each treatment was obtained and the reduction rate with respect to their corresponding control was estimated. Data were analysed using an ANOVA test using a completely randomised design in the SAS programme. Butlerius butleri reduced the Hc-L3, population by 91.8%, whereas its population increased 131.6 times. The interactions between B. butleri and Pr and R resulted in 80.9% and 62.5% nematode reduction and B. butleri increased its populations 268.3 and 82.7 times, respectively. This experiment was performed only once, so this can be considered a preliminary report at this time. This study provides evidence for the first time that B. butleri feeds on one of the most economically important nematodes of small ruminants, Hc-L3.

Free-living nematode, Panagrellus redivivus, was tested as live food for blue swimming crab, Portunus pelagicus larvae during the first feeding stage. A series of experiments were conducted to determine the acceptability of the free-living nematodes in P. pelagicus larvae at first feeding. The optimum nematode density and the response of the larvae to nutritionally enriched nematode were also been examined. Newly hatched P. pelagicus, distributed into each 50 mL experiment plastic containers contains 30 individual P. pelagicus larvae. Microworms will be given four times day−1 at around 0800 h, 1100 h, 1400 h and 1600 h after the water exchange. Duration of feeding experiments was up to day 10–15 and results show that their survival rate of zoea 1: 56%, zoea 2: 74%, zoea: 3 84% and zoea 4: 66%. The results also showed that P. redivivus exhibited better Specific Growth Rate from Zoea 2 to Zoea 3 stage compared to the Artemia based diets. Observations indicated that the P. pelagicus, larvae readily fed on free-living nematodes as early as 2 days post-hatching, the start of exogenous feeding. Studies focusing on the alternative live food at the early larval stages can improve culture information for future and mass aquaculture commercialization of portunid crabs. Keywords: Aquaculture, Crustacean, Early feeding, Nursery culture, Seed production

Nematode-trapping fungi constitute a guild of species that develop specialized trapping structures with which they capture and digest nematodes. These traps are not constitutively present, but instead develop in the presence of nematodes3; they attract them2, adhere to their cuticle and eventually pierce it, extending hyphae inside their bodies. Instituto de Microbiología y Zoología Agrícola (IMYZA) Fil: Maestro, Mariano. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina Fil: Sauka, Diego Hernan. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; Argentina

A strain of the fungus Gliocladium roseum YMF1.00133 was found to secrete nematicidal metabolites against nematodes Panagrellus redivivus, Caenothabditis elegans and Bursaphelenchus xylophilus in experiments searching for nematicidal fungi. Through bioassay-guided fractionations, a unique trioxopiperazine alkaloid, gliocladin C (compound 1), and an alkylane resorcinol, 5-n-heneicosylresorcinol (compound 2) were obtained from the methanol extract of the fungus and determined by single-crystal X-ray analysis and spectroscopic data. In vitro immersion experiments showed that the ED50 values of compounds 1 and 2 after 24 h incubation were 15 and 30 μg/mL against C. elegans, 50 and 80 μg/mL against P. redivivus, and 200 and 180 μg/mL against B. xylophilus, respectively. The X-ray diffraction data of compound 1 and the nematicidal activity of compounds 1 and 2 were reported for the first time.

There is much interest in the economic use of Agave tequilana Weber leaves to control major agro-industrial pests, because an estimated 741,000 tons of leaves are wasted each year as a byproduct of the tequila industry. Hexane and ethyl acetate extracts and the insecticidal activity of juice from the leaves of A. tequilana were evaluated against silverleaf whitefly, Bemisia tabaci (Gennadius), and nematicidal action against Panagrellus redivivus L. Undiluted juice killed 31%, hexane extract diluted to 4% killed 100%, and the check Herald®, a pyrethroid, at a concentration of 0.8% killed 100% of whiteflies. Juice diluted to 12%, ethyl acetate extract at 0.4%, and the check Vydate-L®, a carbamate, at 0.8% killed 100% of P. redivivus nematodes. Juice from A. tequilana leaves contained alkaloids, flavonoids, saponins, tannins, triterpenes, and/or steroids that might have killed silverleaf whitefly and P. redivivus. The results demonstrated that juice from leaves of A. tequilana, which are a byproduc...

Four nematophagous fungi (NF) were identified by traditional and molecular techniques, and their in vitro predatory activity (PA) against Haemonchus contortus (Hc), and Panagrellus redivivus (Pr) was assessed. Additionally, the nematocidal activity (NA) of fungal organic extracts (OEs) obtained from a methanol/dichloromethane system was assessed. Fungi were grown in PDB medium under shaking (SchC) and static conditions (StatC). The PA of Arthrobotrys conoides (Ac), A. oligospora (Ao), A. arthrobotryoides (Aa) and Purpureocillium lilacinum (Pl) against Hc were 75, 71, 66 and 52%, respectively. Meanwhile, the PA against Pr for same fungal genera/species were 99.8, 99.9, 99.4 and 96.3%, respectively. The highest NA of the OEs were 89.5, 81.6 and 72.1% for Aa, Ac and Ao, respectively, under StatC. Moreover, Pl cultured under SchC caused 78% Hc larval mortality. The four assessed NF and their OEs are promising candidates as potential biocide agents against parasitic nematodes.

Control of phytonematodes is very hard and requires a combination of techniques to succeed. Alternative control through plant extracts may result in the discovery of nematicide substances. Research aimed at evaluating the effect of 33 plants submitted to aqueous extraction against Panagrellus redivivus in vitro. Concentrations were prepared at 1.25, 2.5, 5, 10, and 20%. Monitoring happened at 0, 6, 12, 24 and 30 hours after preparation. Counting considered dead nematodes subtracted from alive ones. Juveniles were also counted, and extract efficiency was expressed in percentage of control or stimuli. Data were submitted to variance analysis. Significant results got with the Scott-Knott test (5%), and multiple linear regression analysis. Extracts were observed acting as controllers, but also as stimulators to nematode reproduction. The best controlling performance was set by Carica papaya (-66% at 20%; -33.7% at 10%), Euphorbia milii (-37% at 20%), Psychotria carthagenensis (-25.5% at 2.5%), Clusia variegate (-22% at 20%), and Zamioculcas zamiifolia (-21.5% at 20%). Stimulator extracts were Mentha villosa at 10% (+148%) and 2.5% (+131.5%), followed by Aloe vera (+123% at 5%), Schinus molle (+112.5% at 10%), Schefflera arboricola (+93.5% at 5%), C. variegate (+89% at 5%), and S. molle (+88% at 5%). Some extracts kept population stable throughout the experiment, presenting lower control indexes. Besides an additive effect, there was an individual influence of concentration or time on control. RESUMO O controle de fitonematoides é muito difícil e requer uma combinação de técnicas para ter sucesso. O controle alternativo via extrato vegetal pode resultar na descoberta de substâncias nematicidas. Esta pesquisa objetivou avaliar o efeito de 33 plantas submetidas à extração aquosa contra Panagrellus redivivus in vitro. As concentrações foram preparadas a 1,25; 2,5; 5; 10; e 20%. O monitoramento ocorreu em 0, 6, 12, 24 e 30 horas após a preparação. Para a contagem, foram considerados nematoides mortos subtraídos dos vivos. Nematoides jovens também foram contados, e a eficiência dos extratos foi expressa em porcentagem de controle ou de estímulo. Os dados foram submetidos à análise de variância. Resultados significativos foram analisados pelos testes de Scott-Knott (5%) e análise de regressão múltipla. Foram observados extratos agindo como controladores, bem como estimuladores da reprodução de nematoides. A melhor performance de controle foi obtida por Carica papaya (-66% a 20%; -33,7% a 10%), Euphorbia milii (-37% a 20%), Psychotria carthagenensis (-25,5% a 2,5%), Clusia variegate (-22 a 20%) e Zamioculcas zamiifolia (-21,5% a 20%). Os extratos estimuladores foram Mentha villosa a 10% (+148%) e 2,5% (+131,5%), seguido por Aloe vera (+123% a 5%), Schinus molle (+112.5% a 10%), Schefflera arboricola (+93.5% a 5%), C. variegate (+89% a 5%) e S. molle (+88% a 5%). Alguns extratos mantiveram a população estável durante todo o experimento, apresentando menores índices de controle. Além do efeito aditivo houve uma influência individual da concentração e do tempo no controle.

Synadenium grantii is a Euphorbiaceae plant commonly found in Brazil, known as Janaúba or Leitosinha, whose latex is traditionally used for several purposes. However, it is not known whether the nematicidal action of this plant latex occurs due to the action of proteases. The present work aims to evaluate the nematicidal activity of proteases from Synadenium grantii latex on Meloidogyne incognita and Panagrellus redivivus. S. grantii latex used in the present study was collected from specimens found in Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil. The drained latex was collected in Eppendorf microtubes and immediately stored on ice at 4 °C. After this extraction, the latex was frozen (-20 °C) during 2 hours, thawed at room temperature (25 °C) and centrifuged at 10,000 g at 4 °C for 30 minutes to remove larger particles and concentrate the proteases. After the centrifugation, assays of enzymatic activity were performed in order to know in which of the phases the enzymes were found. S. grantii latex presented protease, but no chitinase activity. The results show that there was a significant difference (p

000. Within the nematode class Chromadorea, the suborder Tylenchina is an ecologically and morphologically diverse assemblage of nematodes that includes free-living microbivores, fungivores and various types of plant parasites. A recent nematode classification system based largely on SSU rDNA phylogenetic trees classified suborder Tylenchina to include four infraorders: Panagrolaimomorpha, Cephalobomorpha, Tylenchomorpha and Drilonematomorpha, and phylogenetic relationships among species of these infraorders have not always been robustly supported. In this study, we determined the complete mitochondrial genome sequences of three Tylenchina species (Aphelenchus avenae [Aphelenchidae, Tylenchomorpha], Halicephalobus gingivalis, Panagrellus redivivus [Panagrolaimomorpha]) and the partial genome sequence of Acrobeles complexus (Cephalobomorpha) and used these sequences to infer phylogenetic relationships among representatives of the Tylenchina and other nematodes. Phylogenetic analysis of amino acid sequences for 12 protein-coding genes of 100 nematode species supports monophyly of: Chromadorea, Spiruromorpha, Oxyuridomorpha, Ascarididae + Toxocaridae + Anisakidae, Meloidogynidae + Pratylenchidae + Heteroderidae and Aphelenchoidea. Bayesian and maximum-likelihood analyses also show the nested position of Diplogasteromorpha within Rhabditomorpha, and Rhigonematomorpha within Ascaridomorpha. These analyses also show non-monophyly of: clade III, Ancylostomatidae, Panagrolaimomorpha, Tylenchina and Tylenchomorpha. Reconstructed mitochondrial genome phylogeny also revealed that among two main Tylenchomorpha groups, the monophyletic group representing Aphelenchoidea species was sister to the large clade consisting of Ascaridomorpha, Diplogasteromorpha, Rhabditomorpha and Rhigonematomorpha and some Panagrolaimomorpha species, whereas Tylenchoidea species were sister to the most inclusive assemblage containing all infraordinal groups of Chromadorea, except for P. redivivus (Panagrolaimomorpha) and Acrobeles complexus (Cephalobomorpha). The monophyly of Aphelenchoidea (i.e. sister relationship between Aphelenchidae and Aphelenchoididae) recovered in this study indicates that similarity in certain aspects of pharyngeal structure between these two families appears best explained by common ancestry, rather than convergent evolution.

Chemical investigation on the cultures of the fungus Cordyceps spp., a strain from cell fusion between Cordyceps militaris and Cordyceps cicadae, resulted in the isolation of 13 compounds including 2 new ones named 2-(5-(3-oxobutyl) furan-2-yl) acetic acid (1) and cordycepone (2). Their structures were elucidated from the analysis of 1D/2D NMR and CD data. Among them, compounds 1, 7–9, at a concentration of 50 μg/ml, showed weak inhibitory activity against AChE. Moreover, compounds 6, 9, and 11 showed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 79.0, 71.7, and 72.3% at 2.5 mg/ml, respectively.

This study was aimed to evaluate the in vitro lethal activity of the nematophagous fungi Clonostachys rosea against 5 nematodes species belonging to different taxa. Two groups of 35 Petri dishes (PD) each were divided into 5 series of 7 (PD). Group 1 (series 1, 2, 3, 4, and 5) contained only water agar; meanwhile group 2 plates (series 6, 7, 8, 9, and 10) contained C. rosea cultures growth on water agar. Every plate from the two groups was added with 500 nematodes corresponding to the following genera/specie: Haemonchus contortus, Caenorhabditis elegans, Rhabditis sp., Panagrellus redivivus, and Butlerius sp. After 5-day incubation at room temperature, free (nontrapped) larvae were recovered from plates using the Baermann funnel technique. Recovered nematodes were counted and compared with their proper controls. Results shown an important reduction percentage of the nematode population attributed to the fungal lethal activity as follows: H. contortus (L3) 87.7%; C. elegans 94.7%; Rhabditis sp. 71.9%; P. redivivus 92.7%; and Butlerius sp. 100% (p≤0.05). The activity showed by C. rosea against the H. contortus can be crucial for further studies focused to the biological control of sheep haemonchosis, although the environmental impact against beneficial nematodes should be evaluated.

Fish larvae are fed with artemia and it is very expensive. Although it is widely and successfully used, Artemia salina is an expensive raw material which is collected from nature and needs to have an alternative fro future use. Panagrellus redivivus, which is a free living nematode is known to be a suitable species for the first feeding of fish larvae.P. redivivus, microworms, are used by amateur aquarists for aquarium fish but scientific research on the species is limited. Larval feeding is very essential for the fish to be healthy and productive and this study aims to identify Panagrellus redivivus nutritional values for larval feeding. Microworms are fed and cultured in mediums with oatmeal, water and yeast before chemical analyses for nutritional values. Analyzes showed %36, %12.4, %77,78 and %7.69 for proteins, lipids, moisture and ash respectively, Balık larvalarının beslenmesinde kullanılan bir canlı yem türü olan Artemia salina doğal stoklara bağımlı olması nedeniyle maliyetli bir hammaddedir. Her ne kadar Artemia salina oldukça yaygın bir şekilde ve başarılı olarak kullanıyor olsa da, Artemia salina’nın maliyetli ve doğadan toplanan stoklara bağımlı olması bu hammaddenin alternatiflerinin araştırılmasını gerektirmektedir. Serbest yaşayan (parazit özelliği göstermeyen) bir nematod olan Panagrellus redivivus’ un balık larvalarının ilk beslenmesinde kullanıma uygun bir tür olduğu bildirilmektedir. Bu nematodlardan olan mikrokurtlar (Panagrellus redivivus) amatör akvaryumcular tarafından balık larvalarının beslenmesinde sıkça kullanılmaktaysa da bu türlerin kullanımına yönelik bilimsel araştırmalar kısıtlıdır. Bu türlerin Artemia salina yerine kullanılabileceği bazı araştırıcılar tarafından bildirilmektedir. Balık larvalarının iyi beslenmesi bu balıkların ilerleyen dönemlerindeki büyüme performansları, sağlık durumları ve gelişimleri açısından çok önemlidir. Bu çalışmada amaç; adı geçen nematod olan mikrokurt (Panagrellus redivivus)türünün besin değerlerinin belirlenmesidir. Bu amaçla yulaf unu, su ve maya kullanılarak oluşturulan besi ortamında kültüre alınan mikro-kurtlara besin değeri analizleri yapılmıştır. Yapılan analiz sonuçlarına göre mikrokurtların protein, yağ, nem ve kül değerleri sırasıyla % 36, %12.4, %77.78 ve %7.69 olarak bulunmuştur.