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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

Many nematode species are parasitic and threaten the health of plants and animals, including humans, on a global scale. Advances in DNA sequencing techniques have allowed for the rapid and accurate identification of many organisms including nematodes. However, the steps taken from sample collection in the field to molecular analysis and identification can take many days and depend on access to both immovable equipment and a specialized laboratory. Here, we present a protocol to genetically identify nematodes using 18S SSU rRNA sequencing using the MinION, a portable third generation sequencer, and proof that it is possible to perform all the molecular preparations on a fully portable molecular biology lab – the Bentolab. We show that both parasitic and free-living nematode species (Anisakis simplex, Panagrellus redivivus, Turbatrix aceti, and Caenorhabditis elegans) can be identified with a 96–100% accuracy compared to Sanger sequencing, requiring only 10–15 min of sequencing. This protocol is an essential first step toward genetically identifying nematodes in the field from complex natural environments (such as feces, soil, or marine sediments). This increased accessibility could in turn improve global information of nematode presence and distribution, aiding near-real-time global biomonitoring.

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.

Panagrellus redivivus is a nematode with a high protein content and low-cost production. It is successfully used in the larviculture of shrimp, however, it has not yet been evaluated as feed for Betta splendens larvae. Thus, the objective of this study was to evaluate P. redivivus as feed for betta larvae maintained at different depths of water. The experiment was based on a completely randomized 3 9 2 factorial design, represented by two feed types and one alternating feeding regime plus two water depths (2.5 and 5.0 cm). The Artemia feed promoted the highest weight gain, followed by the alternating feeding regime. The single use of the nematode as live feed produced the poorest weight gain. The water depth and the feeding method influenced the specific growth rate (SGR). At a depth of 2.5 cm, the alternating feeding promoted similar SGR compared to fish fed with Artemia only. Furthermore, at the greater water depth an improvement in SGR was observed in fish fed Artemia only, but the similarity to alternating feeding regime remains. Thus, the inclusion of nematode is an appropriate and lower cost feed strategy for the betta larviculture independent of water depths. Made available in DSpace on 2019-03-02T00:38:42Z (GMT). No. of bitstreams: 1 Coutoetal2018AquacultureResearchPanagrelus.pdf: 273599 bytes, checksum: b3475748cc13d61a9c031c38ae565dc7 (MD5) Previous issue date: 2019-02-27

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.

Soil microbes are a major food source for free-living soil nematodes. It is known that certain soil bacteria have evolved systems to combat predation. We identified the nematode-antagonistic Pseudomonas protegens strain 15G2 from screening of microbes. Through protein purification we identified a binary protein, designated Pp-ANP, which is responsible for the nematicidal activity. This binary protein inhibits Caenorhabditis elegans growth and development by arresting larvae at the L1 stage and killing older-staged worms. The two subunits, Pp-ANP1a and Pp-ANP2a, are active when reconstituted from separate expression in Escherichia coli . The binary toxin also shows strong nematicidal activity against three other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.), but we did not find any activity against insects and fungi under test conditions, indicating specificity for nematodes. Pp-ANP1a has no significant identity to any known proteins, while Pp-ANP2a shows ∼30% identity to E. coli heat-labile enterotoxin (LT) subunit A and cholera toxin (CT) subunit A. Protein modeling indicates that Pp-ANP2a is structurally similar to CT/LT and likely acts as an ADP-ribosyltransferase. Despite the similarity, Pp-ANP shows several characteristics distinct from CT/LT toxins. Our results indicate that Pp-ANP is a new enterotoxin-like binary toxin with potent and specific activity to nematodes. The potency and specificity of Pp-ANP suggest applications in controlling parasitic nematodes and open an avenue for further research on its mechanism of action and role in bacterium-nematode interaction. IMPORTANCE This study reports the discovery of a new enterotoxin-like binary protein, Pp-ANP, from a Pseudomonas protegens strain. Pp-ANP shows strong nematicidal activity against Caenorhabditis elegans larvae and older-staged worms. It also shows strong activity on other free-living nematodes ( Pristionchus pacificus , Panagrellus redivivus , and Acrobeloides sp.). The two subunits, Pp-ANP1a and Pp-ANP2a, can be expressed separately and reconstituted to form the active complex. Pp-ANP shows some distinct characteristics compared with other toxins, including Escherichia coli enterotoxin and cholera toxin. The present study indicates that Pp-ANP is a novel binary toxin and that it has potential applications in controlling parasitic nematodes and in studying toxin-host interaction.

The purpose of this study was to investigate the effectiveness of 11 different culture media for production of the free-living nematode Turbatrix aceti. Several other harvesting methods were tested in addition to mass production. A further focus was the investigation of amino acid alterations caused by the application of various media during the culture of T. aceti and two additional nematode species, Panagrellus redivivus and Caenorhabditis elegans. Finally, a cost analysis for the production of T. aceti was generated and its outcome compared to the production of conventional live feed organisms. Altogether 11 liquid culture media were tested for mass production of the nematode Turbatrix aceti using a minimum of effort in terms of labour and costs. Six harvesting methods, including filtration as well as active swimming of T. aceti were evaluated. Additional to the culture of T. aceti in four of the above-mentioned media, the nematodes P. redivivus and C. elegans were cultured on two different solid media. Cost analysis for the production of T. aceti includes those of the media, the equipment, as well as the labour costs for culture and harvest. An average density of approx. 30 × 106 ± 8.13 × 106 nematodes L−1 was achieved for T. aceti. The most efficient method (20 μm filtration) allowed harvesting 85.3 ± 2.7% of the nematodes from the medium without disturbing the particles. Lowest efficiency was achieved by combining sedimentation and filtration, accomplishing a harvest of 42.1 ± 5.8%. The amino acid profile of all three nematode species turned out to be both stable and very similar. Amino acid enrichment had little effect. The costs for producing one million T. aceti individuals ranged between 5.39 and 6.19 €, where labour costs accounted for 73 to 84% of the total production costs. In conclusion, T. aceti appears to be very robust, easy to handle, as well as cheaper to cultivate compared to other live-feed organisms. Therefore, its use in commercial aquaculture should be given future consideration.

Nematophagous fungi produce chitinases that may be important in the process of infection of eggs and larvae of nematodes. This study aimed to produce, purify, characterise and test the nematicidal action of extracellular chitinases produced by Monacrosporium thaumasium on Panagrellus redivivus. Mycelia from M. thaumasium were used to inoculate a solid medium for chitinase production. The enzymes were purified using a specific technique of adsorption for chitinases. The chitinase activity was determined at different pHs and temperatures. NF34 produced two distinct chitinases (27 and 30 kDa). After 72 hours, these enzymes provided a significant reduction (80%; p < 0.01) of the number of P. redivivus larvae, compared to control. It was shown that isolate NF34 produced chitinases with nematicidal activity. Thus, other experimental designs on geohelminths or even arthropods that transmit diseases may become a new aspect of the field of study of biological control using predatory nematophagous fungi.

In November 2017, vertical cankers were observed in the trunk of 120 trees growing in a plantation of hybrid poplar (Populus × euramericana) of 12 ha in the district of Santarem (Portugal), suggesting a bacterial disease. The trees had been imported from France and planted in 2011. The vertically cracked bark presented a whitish creamy mass delimited by dark brown exudates. Under the microscope, the creamy mass was found to be composed by a large number of individuals of the free-living, bacte-riophagous nematode Panagrellus redivivus, as also reported by Toth et al. (2013), who suggested that large numbers of bacteria are present in the bark canker. Samples of cankers and exudates were macerated and extracts plated on King’s B medium. Cultures yielded bacterial isolates showing colonies white-ivory colored, bright, round, slightly convex, and not fluorescent under ultraviolet light. Nine isolates were selected and further characterized by phenotypic (biochemical data, fatty acid profiles, and carbon source utilization by Biolog GEN III and API 20E test plates) and phylogenetic analysis. A Lonsdalea populi strain was also included for comparison. Colonies were gram-negative, facultative anaerobic, levan and esculin hydrolysis positive, but did not have cytochrome c oxidase or urease activity and did not induce a hypersensitivity response on tobacco plants. The symptomatology in the affected poplars and the results of the phenotypic analyses of the isolates were similar to those reported for L. populi (Berruete et al. 2016; Li et al. 2014, 2017; Toth et al. 2013). Partial sequences of the 16S rDNA gene and housekeeping genes gapA, atpD, gyrB, and infB showed 99 to 100% identity with isolates of L. populi available at the GenBank database. The neighbor-joining phylogenetic tree, inferred by the CIPRES Science Gateway after online alignment by the MAFFT program version 7 of 16S rDNA and housekeeping gene sequences, further identified the isolates as L. populi. Sequences from two representative isolates (EFA-L5 and EFA-L6) from this study were submitted to GenBank (accession nos. MH469711 and MH469712 for 16S rRNA gene, MH496625 and MH496626 for gapA, MH559348 and MH559349 for atpD, MH824634 and MH824635 for gyrB, and MH899112 and MH899113 for infB). Pathogenicity of EFA-L5 and EFA-L6 isolates was tested on nursery plants of P. × euramericana ‘I-214’. For each bacterial isolate, a suspension in water was prepared as inoculum (10⁷ CFU/ml). Five plants were inoculated with EFA-L5 and another five with EFA-L6. In each inoculated plant, two incisions were made in the trunk, and 100 µl of the corresponding bacterial suspension applied in each incision. Sterile distilled water was applied in incisions similarly made in the trunk of five control plants. All plants were placed in a growth chamber at 85 to 90% humidity and 22 ± 3°C. A watery necrosis area was observed in all inoculated plants 7 days after inoculation, but not in control plants. After 3 months, decay and death of most inoculated plants were observed. L. populi was reisolated from symptomatic plants, thus fulfilling Koch’s postulates. L. populi has been reported causing bark canker disease in poplar in Hungary, China, and Spain (Berruete et al. 2016; Li et al. 2014; Toth et al. 2013). To our knowledge this is the first report of L. populi on poplar in Portugal. More research is needed to know the distribution of bark canker disease in this country, because it could have a significant economic impact on poplar plantations.

Nematodes are the most abundant invertebrates in soils and are key prey in soil food webs. Uncovering their contribution to predator nutrition is essential for understanding the structure of soil food webs and the way energy channels through soil systems. Molecular gut content analysis of consumers of nematodes, such as soil microarthropods, using specifi c DNA markers is a novel approach for studying predator – prey interactions in soil. We designed new specifi c primer pairs (partial 18S rDNA) for individual soil-living bacterial-feeding nematode taxa ( Acrobeloides buetschlii, Panagrellus redivivus, Plectus velox and Plectus minimus ). Primer specifi city was tested against more than 100 non-target soil organisms. Further, we determined how long nematode DNA can be traced in the gut of predators. Potential predators were identifi ed in laboratory experiments including nine soil mite (Oribatida, Gamasina and Uropodina) and ten springtail species (Collembola). Finally, the approach was tested under fi eld conditions by analyzing fi ve mite and three collembola species for feeding on the three target nematode species. Th e results proved the three primer sets to specifi cally amplify DNA of the respective nematode taxa. Detection time of nematode DNA in predators varied with time of prey exposure. Further, consumption of nematodes in the laboratory varied with microarthropod species. Our fi eld study is the fi rst defi nitive proof that free-living nematodes are important prey for a wide range of soil microarthropods including those commonly regarded as detritivores. Overall, the results highlight the eminent role of nematodes as prey in soil food webs and for channelling bacterial carbon to higher trophic levels.

To use unique nematicidal mechanism of Stropharia, the strain 1.2052 was evaluated for its potential to control the root-knot nematode Meloidogyne incognita on tomato. In vitro, the inhibition rate in 24 h of Stropharia sp. 1.2052 isolate was 100% for second-stage juveniles of M. incognita and Panagrellus redivivus, 41.81% for Caenorhabiditis elegans and 99.25% for Bursaphelenchus xylophilus, respectively. In pot experiments, isolate 1.2052 reduced the root-knots to 68.16 to 84.19% in one month and 45.28 to 88.24% in two months after treatment, respectively. The reduction of nematodes in soil ranged from 26.39 to 61.18% compared to the negative control. There were significant efficacies for control of root knot nematodes on tomato. Key words: Stropharia, Meloidogyne incognita, biological control, root-knot nematodes.

Background Species of Cephalotaxus (the plum yews) produce nematotoxic compounds of unknown identity. Consequently, bioassay-guided fractionation was employed to identify the compound(s) in Cephalotaxus fortunei twigs and leaves with activity against plant-parasitic nematodes. Results A crude alkaloid extract, particularly drupacine, was responsible for much of the nematotoxicity. The ED50 of drupacine for Bursaphelenchus xylophilus was 27.1 µg mL−1, and for Meloidogyne incognita it was 76.3 µg mL−1. Immersion of M. incognita eggs in 1.0 mg mL−1 crude alkaloid extract (the highest tested concentration) reduced hatch by 36%; immersion of second-stage juveniles (J2) resulted in 72–98% immobility. Crude alkaloid extract and drupacine suppressed protease activity in extracts of the microbivorous nematode Panagrellus redivivus by 50% and 80%, respectively. Application of 0.02–0.5 mg mL−1 crude alkaloid extract to soil with M. incognita inoculum did not significantly reduce pepper plant shoot length or weight, compared with nematode-inoculated, water-treated controls, but the number of eggs and J2 per root system respectively decreased by 69% and 73% at 0.5 mg mL−1. Conclusion Drupacine and a crude alkaloid extract suppress nematode hatch, activity of mixed life stages, and population numbers on plant roots. This is the first demonstration of nematotoxicity of crude Cephalotaxus alkaloids and drupacine. © 2013 Society of Chemical Industry

Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyneincognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of eight catechin polyphenol analogues, (+)-catechin, ( − )-epicatechin (EC), ( − )-gallocatechin (GC), ( − )-epigallocatechin (EGC), ( − )-catechin gallate (CG), ( − )-gallocatechin gallate (GCG), ( − )-epicatechin gallate (ECG) and ( − )-epigallocatechin gallate (EGCG) (1 mm each), and by a preparation from H. glycines cysts. General protease activity detected with the FRET-peptide substrate QXL520-KSAYMRF-K(5-FAM)a and proteasome chymotrypsin-like (CTL) activity detected with succinyl-LLVY-AMC were each inhibited significantly more (PH. glycines cysts inhibited M. incognita CTL activity by 92.07 ± 0.68%, significantly less (PH. glycines (52.86 ± 2.77%), and by only 17.24 ± 0.55% (PP. redivivus preparations. CTL activity was, however, inhibited more than 60% in all preparations by the proteasome-specific inhibitor MG-132. Hatching of M. incognita infective juveniles exposed to 1 mm CG, ECG, GCG or EGCG was reduced by 83.88 ± 4.26%, 69.98 ± 9.14%, 94.93 ± 1.71% and 87.93 ± 2.89%, respectively, while hatching of H. glycines was reduced less than 25% by each analogue. CE had no effect on nematode hatch, but did cause a 60% reduction in mobility of H. glycines infective juveniles exposed overnight to CE in vitro, which was more (PM. incognita infective juvenile mobility (20%).

This study evaluates the potential application of silver nanoparticles (AgNPs) as antimicrobial or nematicidal agents produced by the extremophile Bacillus pumilus, which was isolated from the alkaline Wadi El-Natrun Lake in Egypt. The AgNPs were characterized by ultraviolet–visible absorption spectroscopy, transmission electron microscopy, and energy dispersive x-ray spectroscopy. The size of AgNPs formed ranged from 20.12 to 29.48 nm. Panagrellus redivivus was exposed to different concentrations (0, 50, 100, 150, and 200 µg/mL) of AgNPs in a 5 mL nematode suspension (1×103 mL-1). The best result occurred at AgNP concentrations of 150 and 200 µg/mL, with death rates of 80% and 91%, respectively, following 48 h of exposure. AgNPs also exhibited potent antimicrobial properties when using Gram-negative and Gram-positive human pathogens, with MIC and MBC values of 5 μg/mL and 10 μg/mL, respectively. These laboratory assays prove that biologically synthesized AgNPs are an ecofriendly material that can be used in lieu of solvents or toxic chemicals.

Trichoderma is an important biocontrol agent that produces metabolites harmful to nematodes. We investigated the volatile organic compounds (VOCs) of Trichoderma sp. YMF 1.00416 and examined their abilities to kill nematodes. Chemical investigations of the VOCs from this strain led to the isolation and identification of three metabolites: a new compound, 1β-vinylcyclopentane-1α,3α-diol (1) and two known metabolites, 6-pentyl-2H-pyran-2-one (2) and 4-(2-hydroxyethyl)phenol (3). Nematicidal activity assays showed that compound 2 was nematicidal, and killed > 85% of Panagrellus redivivus, Caenorhabditis elegans, and Bursaphelenchus xylophilus in 48 h at 200 mg/L in a 2 mL vial. Our results will help identify new nematicides.

Live feeds are essential in larval nutrition of many fish and crustacean species. As the consumers' demand for aquaculture products is growing rapidly, the demand for live feeds in larviculture is increasing as well. To satisfy the growing demand, research has taken steps to develop new innovative live feeds. Several studies focused on nematodes as a potential food source for larvae. Production methods, culture media, harvest, and enrichment procedures for nematodes presented in these studies are reviewed here. Many studies fed nematodes to different species of fish and crustaceans to test applicability in larval nutrition. The results of these feeding trials in terms of larval performance as well as ingestion and digestion of nematodes in the larvae's gut are reviewed here as well. In addition, a summary of advantages and disadvantages of nematodes as live food and an outlook on future challenges of production and application of nematodes in larviculture are also presented. In summary, several different production methods including innovative culture media for nematodes have been developed. The species Panagrellus redivivus has been used in most of the reviewed studies. It reproduces extremely fast and can be cultivated by very simple means of production. Other species such as Turbatrix aceti and Caenorhabditis elegans have been tested in a few studies as well. However, a complete production cycle for mass production appropriate for use in aquaculture has not been developed yet for any of these species. Enrichment trials for amino acids revealed only a very limited potential to manipulate amino acid profiles in nematodes. In contrast, fatty acid composition turned out to be quite variable depending on the culture media used for nematode production. By adding oils containing large quantities of essential fatty acids to the culture media, these fatty acids could be enriched in nematodes and provided to larvae. This allows tailoring fatty acid composition according to the needs of the respective larvae. It could be shown that nematodes can be digested by fish larvae even though they possess a robust cuticle. Larval performance depends strongly on the respective species of fish to which the nematodes are fed. Nematodes seemed to work particularly well for crustacean larvae. In penaeid larvae, nematodes turned out to be a good live food that can compete with conventional feeding methods even though there is still room for improvements. For future use in larviculture, appropriate methods for mass production, harvest, and feeding need to be developed. Additionally, more data on optimized feeding levels for different fish and crustacean species will be required.

SUMMARYStudies on anthelmintic resistance in equine parasites do not include facultative parasites.Halicephalobus gingivalisis a free-living bacterivorous nematode and a known facultative parasite of horses with a strong indication of some form of tolerance to common anthelmintic drugs. This research presents the results of anin vitrostudy on the anthelmintic tolerance of several isolates ofHalicephalobusto thiabendazole and ivermectin using an adaptation of the Micro-Agar Larval Development Test hereby focusing on egg hatching and larval development.Panagrellus redivivusandPanagrolaimus superbuswere included as a positive control. The results generally show that the anthelmintic tolerance ofHalicephalobusto both thiabendazole and ivermectin was considerably higher than that of the closely related Panagrolaimidae and, compared to other studies, than that of obligatory equine parasites. Our results further reveal a remarkable trend of increasing tolerance from fully free-living isolates towards horse-associated isolates.In vitroanthelmintic testing with free-living and facultative parasitic nematodes offers the advantage of observing drug effect on the complete life cycle as opposed to obligatory parasites that can only be followed until the third larval stage. We therefore proposeHalicephalobus gingivalisas an experimental tool to deepen our understanding of the biology of anthelmintic tolerance.

Quantitative investigation of the factors responsible for trap formation in the nematophagous fungus Duddingtonia flagrans F-882 in submerged liquid culture was carried out. The data obtained suggest a complex program for the regulation of zootrophic nutrition in D. flagrans. Optimal concentrations of such carbon and nitrogen sources as sucrose (0.4%), ammonium ions (0.2%), and tryptone (0.2%) promote trap formation in the case of contact with the nematodes Panagrellus redivivus. Increased concentrations of these compounds, however, inhibit trap formation. The sensitivity of the mycelium to nematode excreta depends on the state of the culture and is increased under limitation by certain nutrient components or in the course of prolonged starvation. A direct correlation was found between the number of caught nematodes and the number of chlamydospores formed on the mycelium. The nutrients obtained from the nematode biomass are used for formation of additional chlamydospores (on average, about 20 chlamydospores per nematode). Environmental and evolutionary aspects of the role of zootrophic nutrition in carnivorous fungi are discussed.

Objective: The main objective of this study is to evaluate the chemical and bioactive properties of Eugenia stipitata (Myrtaceae) fruit seeds collected in the Andean region of Colombia using an ethanolic extract, a dichloromethane fraction (DF), and a hydroalcoholic residue. Methods: E. stipitata seeds were evaluated using bromatological analysis; these were macerated (ethanol 96%) and partitioned (dichloromethane). Phytophenols composition of the samples was tested by high-pressure liquid chromatography-mass spectrometry and Folin–Ciocalteu method, then calculated as gallic acid equivalents (GAEs). Antiradical capacity was tested by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and 3-ethylbenzthiazoline-6- sulfonic acid (ABTS•+) and inhibitory concentration 50% (IC50) was calculated; antioxidant capacity was determined using ferric reducing antioxidant power, oxygen radical absorbance capacity, and OH• radical and hemolysis inhibition assays. Anthelmintic activity against Panagrellus redivivus and ovine gastrointestinal (GI) nematodes and toxicity on human blood cells were tested. Results: E. stipitata seeds contain protein, sulfur, boron, iron, and copper. The ethanolic extract exhibited significant anthelmintic activity against free-living and GI nematodes, which would be associated with the phytophenols content, mostly tannins (29.14 g GAE/100 g). DF displayed the highest antiradical capacity in DPPH• and ABTS•+ (IC50: 2.65 and 0.33 mg/l, respectively) methods, antioxidant capacity, and hemolysis inhibition of human erythrocytes (IC50: 200 mg/l). There were no toxic metabolites to human blood cells. Conclusion: These findings would be useful for promoting the use of E. stipitata seeds, collected in the Colombian Andean region, in biotechnological processes. This is the earliest paper showing a study carried out in Colombia with an interest in evaluating chemical and biological characteristics of E. stipitata seeds.

Trichoderma spp. play an important role in biotic control, and several are efficacious against nematodes. To study the potential of Trichoderma species in controlling nematodes, fungal filtrates of 329 Trichoderma strains were evaluated for their nematicidal activity against Panagrellus redivivus and Caenorhabditis elegans. Fifteen strains exhibited nematicidal activity against P. redivivus, and 14 strains showed activity against C. elegans. The strain YMF1.02647 showed strong nematicidal activity against both nematodes, and the culture broth could cause more than 90% mortality to the tested nematodes within 48 h. A nematicidal compound was isolated from ethyl acetate extract of Trichoderma YMF1.02647 based on bioassay-guided fractionation. The compound was identified as trichodermin according to the spectroscopic data, which could kill more than 95% both P. redivivus and C. elegans in 72 h at 0.4 g l(-1).

Extracts prepared from the microbivorous nematode Panagrellus redivivus and the plant-parasitic nematode Meloidogyne incognita were used to provide general protease activities for peptide substrate screening and species comparisons. Each extract was evaluated for its ability to degrade a broad range of nematode FMRFamide-like peptides (FLPs), key regulatory messengers governing nematode growth and development. Clear quantitative differences between the two extracts were observed using FMRFamide as a substrate. Extract potency assessed at EC50 (μg/μ l extract protein for 50% substrate digestion) was 1.8-fold greater for P. redivivus than for M. incognita, and potency assessed at EC90 was 2.5-fold greater. An overall potency difference was also present when screening the digestion of 17 nematode FLPs, but it was not universal. The mean percentage digestion of eight of the 17 FLPs was greater (P P. redivivus extract (76.3 ± 8.2) than with M. incognita extract (38.1 ± 8.7), but the means for the other nine FLPs were not different. Three FLPs (KPSFVRFa, AQTFVRFa, RNKFEFIRFa) were degraded extensively by the extracts of both species, and two FLPs (SAPYDPNFLRFa, SAEPFGTMRFa) were degraded 2.9-fold and 5.3-fold greater, respectively, with M. incognita extract than with P. redivivus extract. The ability of each extract to degrade FMRFa and KSAYMRFa was significantly reduced by using peptide analogues containing single d-amino acid substitutions, and the substitution effects were positional. Both FMRFa and KSAYMRFa were competitive substrates for aminopeptidases in each extract, but only the competitive ability of FMRFa was reduced by d-amino acid substitution. The variety and complexity of nematode FLP degradation by preparations representing phylogenetically and developmentally different nematode sources are discussed.