Evidence map›Paper›PMID 40069896›Full record

ArticleParasites & vectors2025

Description of Heterorhabditis americana n. sp. (Rhabditida, Heterorhabditidae), a new entomopathogenic nematode species isolated in North America.

Ricardo A R Machado, Joaquín Abolafia, María-Cristina Robles, Alba N Ruiz-Cuenca, Aashaq Hussain Bhat, Ebrahim Shokoohi, Vladimír Půža, Xi Zhang, Matthias Erb, Christelle A M Robert and 1 more

Abstract read
In one paragraph

Article in Parasites & vectors, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Native Entomopathogenic Nematodes from Peru ControlInternational journal of molecular sciences · 2026
    Article
  2. Journal of nematology · 2025
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Ricardo A R MachadoExperimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland. rarm.machado@gmail.com.
Joaquín Abolafia *Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, Spain.
María-Cristina Robles *Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, Spain.
Alba N Ruiz-Cuenca *Departamento de Biología Animal, Biología Vegetal y Ecología, Universidad de Jaén, Campus 'Las Lagunillas', Jaén, Spain.
Aashaq Hussain Bhat *Experimental Biology Research Group, Institute of Biology, Faculty of Sciences, University of Neuchâtel, Neuchâtel, Switzerland.
Ebrahim Shokoohi *Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Sovenga, 0727, South Africa.
Vladimír PůžaInstitute of Entomology, Biology Centre of the Czech Academy of Sciences, CAS, 37005, České Budějovice, Czech Republic.
Xi ZhangInstitute of Plant Sciences, University of Bern, Bern, Switzerland.
Matthias ErbInstitute of Plant Sciences, University of Bern, Bern, Switzerland.
Christelle A M RobertInstitute of Plant Sciences, University of Bern, Bern, Switzerland.
Bruce HibbardPlant Genetics Research Unit, United States Department of Agriculture (USDA)-Agricultural Research Service, Columbia, MO, USA.

Funding

European Research Council ERC-2019-STG949595Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung 186094Swiss National Science Foundation 155781Swiss National Science Foundation 189071
6 · The paper itself

Abstract

backgroundHeterorhabditis are important biological control agents in agriculture. Two Heterorhabditis populations, S8 and S10, were isolated from agricultural soils in the United States of America. Molecular analyses, based on mitochondrial and nuclear genes, showed that these populations are conspecific and represent a novel species of the "Bacteriophora" clade. This species was named Heterorhabditis americana n. sp. and is described in this study.

methodsTo describe H. americana n. sp., we carried out phylogenetic reconstructions using multiple genes, characterized their morphology, conducted self-crossing and cross-hybridization experiments, and isolated and identified their symbiotic bacteria.

resultsHeterorhabditis americana n. sp. is molecularly and morphologically similar to H. georgiana. Morphological differences between the males of H. americana n. sp. and H. georgiana include variations in the excretory pore position, the gubernaculum size, the gubernaculum-to-spicule length ratio, the tail length, and the body diameter. Infective juveniles (IJs) of H. americana n. sp. differ from H. georgiana IJs because H. americana n. sp. IJs have an invisible bacterial cell pouch posterior to the cardia and a small posterior phasmid, whereas H. georgiana IJs have a visible bacterial cell pouch and an inconspicuous phasmid. Hermaphrodites of H. americana n. sp. and H. georgiana are differentiated by the body length, the nerve ring distance from the anterior end, the excretory pore distance from the anterior end, the anal body diameter, and the c' ratio. Females of H. americana n. sp. can be differentiated from H. georgiana females by the anal body diameter and the c' ratio. Reproductive isolation was confirmed, as H. americana n. sp. does not produce viable offspring with any of the species of the "Bacteriophora" clade. Heterorhabditis americana n. sp. is associated with the symbiotic bacterium Photorhabdus kleinii.

conclusionsBased on the observed morphological and morphometric differences, the distinct phylogenetic placement, and the reproductive isolation, the nematode isolates S8 and S10 represent a novel species, which we named Heterorhabditis americana n. sp. This study provides a detailed characterization of this novel species, contributing to enhancing our knowledge of species diversity and evolutionary relationships of the Heterorhabditis genus.

Indexed as

RhabditidaRhabditoideaAnimalsFemaleMaleNorth AmericaPhylogenySoilSymbiosisUnited StatesSoilBiocontrol agentsEntomopathogenic nematodesNematode morphologyPhotorhabdusPhylogeneticsSpecies descriptionTaxonomy

Identifiers

PMID40069896
PMCPMC11899345

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.