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Multi-locus phylogenetic analyses uncover species boundaries and reveal the occurrence of two new entomopathogenic nematode species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp. Cover

Multi-locus phylogenetic analyses uncover species boundaries and reveal the occurrence of two new entomopathogenic nematode species, Heterorhabditis ruandica n. sp. and Heterorhabditis zacatecana n. sp.

Open Access
|Nov 2021

Figures & Tables

Figure 1:

Line drawings of Heterorhabditis ruandica n. sp. (A) A hermaphroditic female. (B) Cephalic region of a hermaphroditic female. (C) Pharyngeal region of a hermaphroditic female. (D) Anterior part of the reproductive system of a hermaphroditic female. (E) Posterior end of a hermaphroditic female. (F) An amphimictic female. (G) Pharyngeal region of an amphimictic female. (H) Posterior end of an amphimictic female. (I) A male adult. (J) Pharyngeal region of a male adult. (K) Posterior region of a male adult. (L) Pharyngeal region of an infective juvenile. (M) Posterior end of an infective juvenile. (N) An infective juvenile.
Line drawings of Heterorhabditis ruandica n. sp. (A) A hermaphroditic female. (B) Cephalic region of a hermaphroditic female. (C) Pharyngeal region of a hermaphroditic female. (D) Anterior part of the reproductive system of a hermaphroditic female. (E) Posterior end of a hermaphroditic female. (F) An amphimictic female. (G) Pharyngeal region of an amphimictic female. (H) Posterior end of an amphimictic female. (I) A male adult. (J) Pharyngeal region of a male adult. (K) Posterior region of a male adult. (L) Pharyngeal region of an infective juvenile. (M) Posterior end of an infective juvenile. (N) An infective juvenile.

Figure 2:

Light microscope micrographs of Heterorhabditis ruandica n. sp. (A) An amphimictic female (black arrow pointing at the position of the vulva, white arrow pointing at the anus). (B) Pharyngeal region of an amphimictic female. (C) Posterior end of an amphimictic female. (D) Vulva of an amphimictic female. (E) A male adult. (F) Pharyngeal region of a male adult. (G) Posterior end of a male adult (arrows pointing at the genital papillae).
Light microscope micrographs of Heterorhabditis ruandica n. sp. (A) An amphimictic female (black arrow pointing at the position of the vulva, white arrow pointing at the anus). (B) Pharyngeal region of an amphimictic female. (C) Posterior end of an amphimictic female. (D) Vulva of an amphimictic female. (E) A male adult. (F) Pharyngeal region of a male adult. (G) Posterior end of a male adult (arrows pointing at the genital papillae).

Figure 3:

Light microscope micrographs of Heterorhabditis ruandica n. sp. (A) A hermaphroditic female. (B) Anterior end of a hermaphroditic female. (C) Pharyngeal region of a hermaphroditic female. (D) Posterior end of a hermaphroditic female. (E) A sheathed third stage juvenile (J2). (F) Pharyngeal region of a sheathed third stage juvenile (J2). (G) Posterior end of a sheathed third stage juvenile (J2) (arrow pointing the anus). (H) A non-sheathed third stage juvenile (J3). (I) Pharyngeal region of a non-sheathed third stage juvenile (J3). (J) Posterior end of a non-sheathed third stage juvenile (J3).
Light microscope micrographs of Heterorhabditis ruandica n. sp. (A) A hermaphroditic female. (B) Anterior end of a hermaphroditic female. (C) Pharyngeal region of a hermaphroditic female. (D) Posterior end of a hermaphroditic female. (E) A sheathed third stage juvenile (J2). (F) Pharyngeal region of a sheathed third stage juvenile (J2). (G) Posterior end of a sheathed third stage juvenile (J2) (arrow pointing the anus). (H) A non-sheathed third stage juvenile (J3). (I) Pharyngeal region of a non-sheathed third stage juvenile (J3). (J) Posterior end of a non-sheathed third stage juvenile (J3).

Figure 4:

Scanning electron microscope (SEM) micrographs of Heterorhabditis ruandica n. sp. (A, B) Lip region in lateral and frontal views, respectively, of a hermaphroditic female. (C) Excretory pore of a hermaphroditic female (pointed by an arrow). (D) Vulva of a hermaphroditic female (pointed by an arrow). (E) Tail of a hermaphroditic female in lateral view. (F, G) Lip region of a female adult in lateral and frontal views, respectively. (H) Excretory pore (pointed by an arrow). (I) Vulva of a female adult (pointed by an arrow). (J) Tail of a female adult in ventral view. (K, L) Lip region of a male adult in sublateral and frontal views, respectively. (M, N) Posterior end of a male adult in ventral and lateral views, respectively (arrows pointing the genital papillae). (O) Lip region of a second-stage juvenile (J2) in lateral view. (P) Cuticle of a second-stage juvenile (J2). (Q) Tail of a second-stage juvenile (J2) in lateral and ventral views, respectively. (R) Lip region of a third-stage juvenile (J3) in ventral view (arrow pointing the frontal tooth). (S) Cuticle (arrow pointing the cuticle of a third-stage juvenile).
Scanning electron microscope (SEM) micrographs of Heterorhabditis ruandica n. sp. (A, B) Lip region in lateral and frontal views, respectively, of a hermaphroditic female. (C) Excretory pore of a hermaphroditic female (pointed by an arrow). (D) Vulva of a hermaphroditic female (pointed by an arrow). (E) Tail of a hermaphroditic female in lateral view. (F, G) Lip region of a female adult in lateral and frontal views, respectively. (H) Excretory pore (pointed by an arrow). (I) Vulva of a female adult (pointed by an arrow). (J) Tail of a female adult in ventral view. (K, L) Lip region of a male adult in sublateral and frontal views, respectively. (M, N) Posterior end of a male adult in ventral and lateral views, respectively (arrows pointing the genital papillae). (O) Lip region of a second-stage juvenile (J2) in lateral view. (P) Cuticle of a second-stage juvenile (J2). (Q) Tail of a second-stage juvenile (J2) in lateral and ventral views, respectively. (R) Lip region of a third-stage juvenile (J3) in ventral view (arrow pointing the frontal tooth). (S) Cuticle (arrow pointing the cuticle of a third-stage juvenile).

Figure 5:

Line drawings of Heterorhabditis zacatecana n. sp. (A) A hermaphroditic female. (B) Pharyngeal region of a hermaphroditic female. (C) Anterior part of the reproductive system of a hermaphroditic female. (D) Posterior end of a hermaphroditic female. (E) An amphimictic female. (F) Pharyngeal region of an amphimictic female. (G) Posterior end of an amphimictic female. (H) A male adult. (I) Pharyngeal region of a male adult. (J) Posterior end of a male adult. (K) Pharyngeal region of an infective juvenile. (L) Posterior end of an infective juvenile. (M) An infective juvenile.
Line drawings of Heterorhabditis zacatecana n. sp. (A) A hermaphroditic female. (B) Pharyngeal region of a hermaphroditic female. (C) Anterior part of the reproductive system of a hermaphroditic female. (D) Posterior end of a hermaphroditic female. (E) An amphimictic female. (F) Pharyngeal region of an amphimictic female. (G) Posterior end of an amphimictic female. (H) A male adult. (I) Pharyngeal region of a male adult. (J) Posterior end of a male adult. (K) Pharyngeal region of an infective juvenile. (L) Posterior end of an infective juvenile. (M) An infective juvenile.

Figure 6:

Light microscope micrographs of Heterorhabditis zacatecana n. sp. (A) An amphimictic female (black arrow pointing the vulva, white arrow pointing the anus). (B) Pharyngeal region of an amphimictic female. (C) Posterior end of an amphimictic female. (D) A male adult. (E) Pharyngeal region of a male adult. (F) Posterior end of a male adult (arrows pointing at the genital papillae).
Light microscope micrographs of Heterorhabditis zacatecana n. sp. (A) An amphimictic female (black arrow pointing the vulva, white arrow pointing the anus). (B) Pharyngeal region of an amphimictic female. (C) Posterior end of an amphimictic female. (D) A male adult. (E) Pharyngeal region of a male adult. (F) Posterior end of a male adult (arrows pointing at the genital papillae).

Figure 7:

Light microscope micrographs of Heterorhabditis zacatecana n. sp. (A) A hermaphroditic female. (B) Pharyngeal region of a hermaphroditic female. (C) Posterior end of a hermaphroditic female. (D) A sheathed third stage juvenile (J2). (E) Pharyngeal region of a sheathed third stage juvenile (J2). (F) Posterior end of a sheathed third stage juvenile (J3). (G) A non-sheathed third stage juvenile (J3). (H) Pharyngeal region of a non-sheathed third stage juvenile (J3). (I) Posterior end of a non-sheathed third stage juvenile.
Light microscope micrographs of Heterorhabditis zacatecana n. sp. (A) A hermaphroditic female. (B) Pharyngeal region of a hermaphroditic female. (C) Posterior end of a hermaphroditic female. (D) A sheathed third stage juvenile (J2). (E) Pharyngeal region of a sheathed third stage juvenile (J2). (F) Posterior end of a sheathed third stage juvenile (J3). (G) A non-sheathed third stage juvenile (J3). (H) Pharyngeal region of a non-sheathed third stage juvenile (J3). (I) Posterior end of a non-sheathed third stage juvenile.

Figure 8:

Scanning electron microscope (SEM) micrographs of Heterorhabditis zacatecana n. sp. (A, B) Lip region in lateral and frontal views, respectively, of a hermaphroditic female. (C) Broken cuticle of a hermaphroditic female with a juvenile emerging. (D) Vulva of a hermaphroditic female (pointed by a white arrow). (E) Tail of a hermaphroditic female in lateral view. (F, G) Lip region of a female adult in lateral and frontal views, respectively. (H) Excretory pore of a female adult (pointed by a white arrow). (I) Vulva of a female adult. (J) Tail of a female adult in ventral view. (K, L) Lip region of a male adult in lateral and frontal views, respectively. (M, N) Posterior end of a male adult in lateral and ventral views, respectively (arrows pointing at the genital papillae). (O) Lip region of a second-stage juvenile (J2) in lateral view. (P) Cuticle of a second-stage juvenile (J2) (arrow pointing the excretory pore). (Q) Tail of a second-stage juvenile (J2) in lateral and ventral views, respectively. (R) Lip region of a third-stage juvenile (J3) in dorsal view (arrow pointing the frontal tooth). (S) Cuticle of a third-stage juvenile (J3) (arrow pointing the excretory pore).
Scanning electron microscope (SEM) micrographs of Heterorhabditis zacatecana n. sp. (A, B) Lip region in lateral and frontal views, respectively, of a hermaphroditic female. (C) Broken cuticle of a hermaphroditic female with a juvenile emerging. (D) Vulva of a hermaphroditic female (pointed by a white arrow). (E) Tail of a hermaphroditic female in lateral view. (F, G) Lip region of a female adult in lateral and frontal views, respectively. (H) Excretory pore of a female adult (pointed by a white arrow). (I) Vulva of a female adult. (J) Tail of a female adult in ventral view. (K, L) Lip region of a male adult in lateral and frontal views, respectively. (M, N) Posterior end of a male adult in lateral and ventral views, respectively (arrows pointing at the genital papillae). (O) Lip region of a second-stage juvenile (J2) in lateral view. (P) Cuticle of a second-stage juvenile (J2) (arrow pointing the excretory pore). (Q) Tail of a second-stage juvenile (J2) in lateral and ventral views, respectively. (R) Lip region of a third-stage juvenile (J3) in dorsal view (arrow pointing the frontal tooth). (S) Cuticle of a third-stage juvenile (J3) (arrow pointing the excretory pore).

Figure 9:

Maximum-likelihood phylogenetic tree reconstructed from: (A) the sequences of the cytochrome c oxidase I (COI) of different Heterorhabditis species. A total of 343 nucleotide positions, flanked by primers HCF and HCR, were analyzed; and (B) the concatenated sequences of the following genes/genetic regions of different Heterorhabditis species: the D2–D3 expansion segments of the 28S rRNA (D2–D3), the internal transcribed spacer (ITS) of the rRNA (ITS), and the cytochrome c oxidase I (COI). A total of 1673 concatenated nucleotide positions were included in the reconstruction. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3. *For H. marelatus, H. indica, and H. mexicana, the sequences that were concatenated are derived from different nematode isolates. Heterorhabditis safricana, and H. tayserae were not included as their COI or their D2–D3 sequences, respectively, are not publicly available. Numbers at nodes represent bootstrap values based on 100 replications. Bars represent average nucleotide substitutions per sequence position.
Maximum-likelihood phylogenetic tree reconstructed from: (A) the sequences of the cytochrome c oxidase I (COI) of different Heterorhabditis species. A total of 343 nucleotide positions, flanked by primers HCF and HCR, were analyzed; and (B) the concatenated sequences of the following genes/genetic regions of different Heterorhabditis species: the D2–D3 expansion segments of the 28S rRNA (D2–D3), the internal transcribed spacer (ITS) of the rRNA (ITS), and the cytochrome c oxidase I (COI). A total of 1673 concatenated nucleotide positions were included in the reconstruction. Accession numbers of the nucleotide sequences used for the analyses are shown in Table S3. *For H. marelatus, H. indica, and H. mexicana, the sequences that were concatenated are derived from different nematode isolates. Heterorhabditis safricana, and H. tayserae were not included as their COI or their D2–D3 sequences, respectively, are not publicly available. Numbers at nodes represent bootstrap values based on 100 replications. Bars represent average nucleotide substitutions per sequence position.

Figure 10:

Polymorphism in the sequences of the ITS region (A, B), the D2–D3 region (C), and the COI gene (D-F) showing taxonomically relevant nucleotide positions for Heterorhabditis nematodes of the “Bacteriophora-group”. Nucleotide position numbers of rRNA genes are according to the sequences of C. elegans N2 (NCBI accession number: MN519140) and of mitochondrial genes are according to the sequences of C. elegans N2 (NCBI accession number: AY171203).
Polymorphism in the sequences of the ITS region (A, B), the D2–D3 region (C), and the COI gene (D-F) showing taxonomically relevant nucleotide positions for Heterorhabditis nematodes of the “Bacteriophora-group”. Nucleotide position numbers of rRNA genes are according to the sequences of C. elegans N2 (NCBI accession number: MN519140) and of mitochondrial genes are according to the sequences of C. elegans N2 (NCBI accession number: AY171203).

Figure 11:

Pairwise nucleotide similarities (%) in the sequences of the cytochrome c oxidase I (COI) gene of different Heterorhabditis species. A total of 344 nucleotide positions, flanked by primers HCF and HCR, were analyzed. Accession numbers of gene sequences used are shown in Table S3.
Pairwise nucleotide similarities (%) in the sequences of the cytochrome c oxidase I (COI) gene of different Heterorhabditis species. A total of 344 nucleotide positions, flanked by primers HCF and HCR, were analyzed. Accession numbers of gene sequences used are shown in Table S3.

Figure 12:

Phylogenetic reconstruction based on core genome sequences of Photorhabdus bacterial strains. Numbers at the nodes represent SH-like branch supports. Bar represents average nucleotide substitutions per sequence position. Accession numbers of the genome sequences used for the reconstruction are shown in Table S4.
Phylogenetic reconstruction based on core genome sequences of Photorhabdus bacterial strains. Numbers at the nodes represent SH-like branch supports. Bar represents average nucleotide substitutions per sequence position. Accession numbers of the genome sequences used for the reconstruction are shown in Table S4.

Figure 13:

Dichotomous key to identify the species of the genus Heterorhabditis based on morphological and morphometrical characters of L3 juveniles, of male and female adults, and of hermaphroditic females.
Dichotomous key to identify the species of the genus Heterorhabditis based on morphological and morphometrical characters of L3 juveniles, of male and female adults, and of hermaphroditic females.

Comparative morphometrics of adult males of Heterorhabditis ruandica n_ sp_, H_ zacatecana n_ sp_, and of different closely related Heterorhabditis species_ All measurements are in µm (except ratios and percentages)

SpeciesLBDEPNRNLTSLGL a b c SW%GS%D%CountryReference
H. amazonensis 692–82636–4396–11671–8897–11429–4135–4519–2318.7*7.7**27.5**1.3**120–18744–5695–109Brazil Andaló et al. (2006)
H. atacamensis 842–102542–55116–14969–9399–11924–3640–4917–2219.7*9.6**29.3**1.5**179–24938–51108–126Chile Edgington et al. (2011)
H. bacteriophora 780–96038–46114–13065–8199–10522–3636–4418–2520.8*9.1*34.3*1.8*17450117Australia Poinar (1976)
700–94037–50113–14070–8595–11020–2739–4718–24ArgentinaAgüera de Doucet and Doucet (1986)
689–88038–4678–12355–9092–12421–3234–4817–261.2*147–25641–4968–106Australia Sagun et al. (2015)
782–92792–120103–13958–7684–10528–3751–5317–266.6–8.58.5–1023–321.4–2.2194–28237–57108–157India Bhat et al. (2019a)
805–107542–5784–11184–7580–11924–3939–5117–2716–227.1–1222–411.0–1.7170–22540–6277–136India Rana et al. (2020)
as H. argentinensis # 1000–200042–70145–17064–82103–12028–4942–4920–2616.7*8.3*14.3*1.4*198*62*92*Argentina Stock (1993)
as H. heliothidis £ 1000–120032–60125*125*113–13129–3642–5222–2719–358–1128–381.3*185*51*95*USA Khan et al. (1976)
H. baujardi 818–97045–5371–9354–77105–13228–3833–4518–2216–226.4–8.824–331.5**138–20844–6179**Vietnam Phan et al. (2003)
710–90340–5083–9353–6898–11033–4043–4820–2816–206.7–9.318–28154–20047–6180–90India Vanlalhlimpuia et al. (2018)
as H. somsookae # 737–87037–4468–9372–8390–12020–3032–4517–2320.7**8.3**32.3**1.2**133–19842–5974–99Thailand Maneesakorn et al. (2015)
H. beicherriana 889–119251–73130–15781–108116–14332–4540–4922–2715–237.2–1022–341.3–2.3153–20848–59102–120China Li et al. (2012)
H. downesi 699–87633–4086–9162–7897–10629–3441–4717–1926.6*8.8**27.4**1.4**170–22036–4790Ireland Stock et al., 2002
H. egyptii + 594–84831–5680–9756–8496–10923–3425–5016–2217.1*6.6**19.5**1.5*120–22040–6584–91EgyptAbd–Elgawad and Ameen (2005)
H. floridensis 785–29443–50104–12873–9097–11129–4036–4617–3019.9*7.9**24.1**1.4**133–20947–65112USA Nguyen et al. (2006)
H. georgiana 721–91343–55101–14572–93100–12229–4141–4920–2816.5*7.7**26.1**1.4**150–20051–64100–122USA Nguyen et al. (2008)
H. hambletoni + 510–80038–6080–10080–90Brazil Pereira (1937)
H. hoptha $ 554–83730.9*43–6026–3018–225.9–8.218–371.1*167**55**USA Turco (1970)
H. indica 573–78835–46109–13872–8593–10924–3235–4818–2317.6*6.7**23.0**1.1**18749121India Poinar et al. (1992)
724–86441–4896–11363–8089–10929–3630–4021–3117–207.6–8.622–271.4–1.8155–21049–68101–111India Kajol et al. (2020)
609–91626–5078–10962–8390–11618–3337–4819–2616–286.5–8.225–371.0–1.5116–22549–6486–106India Bhat et al. (2021b)
as H. brevicaudis # 840–95040–4892–10080–88104–11228–3644–4820–242.9*170*47*84*China Liu (1994)
as H. gerrardi # 508–91634–4893–14154–8778–11528–4634–4816–27138–27440–69100–172AustraliaPlichta et al. (2009)
as H. hawaiiensis # 864–113049–8471–14667–112100–14926–4040–5118–26USA Gardner et al. (1994)
as H. pakistanense # 720–101338–43112–13380–110100–10530–4235–4220–2218–247.2–9.819–251.4**144–19148–65110–126Pakistan Shahina et al. (2017)
H. marelatus 805–104648–56110–16861–9599–12324–3841–4918–2215.5*7.8**30.0**1.1**19636–50113**USA Liu and Berry (1996)
960–101048–80107–11689–95115–13037–4748–5221–24USA Stock (1997)
as H. hepialius # 8000–100065–98102–13184–114113–13937–4942–5217–24USA Stock et al. (1996)
H. megidis 800–110044–50139–17696–112122–13435–4346–5417–2418–227–923–311.6*18843122USA Poinar et al. (1987)
H. mexicana 614–80138–47108–14561–8389–10821–3630–4718–3221.7*6.8**27.6**1.1**130–19643–70114–149Mexico Nguyen et al. (2004)
H. noenieputensis 530–77534–4675–10264–7588–10621–3237–4917–2414–185.6–7.921–331.1–1.7202–30138–5681–108S. AfricaMalan et al. (2014)
H. poinari $ 970–110043–70150–15036–6543–5524–3295–10051–9511–97USA Kakulia and Mikaia (1997)
H. ruandica Rw14_NC4a 652–863 40–51 61–109 56–74 84–117 21–29 34–50 16–23 15–21 5.8–9.7 23–36 0.6–1.7 150–306 35–57 61–97 Rwanda This study
H. safricana 777–100940–58104–14752–61105–12627–4935–5419–2720.1*7.9**43.0**1.5*130–25943–6292–133S. Africa Malan et al. (2008)
H. taysearae 648–73638–4878–12054–8885–12320–2930–4212–2115.1*6.5**14.0**1.3**1564688Egypt Shamseldean et al. (1996)
as H. sonorensis # 500–75032–4260–8460–8080–10025–4531–4520–31110–18040–7572–91Mexico Stock et al. (2009)
H. zealandica 848–104436–45130–150110–12830–4148–5519–251.7*24644118N. Zealand Poinar (1990)
as H. heliothidis # 848–104436–45130–150110–12830–4148–5519–251.7*24644118N. Zealand Wouts (1979)
H. zacatecana MEX–39 811–914 41–56 77–109 60–78 71–108 21–33 38–55 15–25 15–25 7.6–12 26–43 1.2–2.5 170–320 40–60 78–134 Mexico This study

Comparative morphometrics of infective juveniles of Heterorhabditis ruandica n_ sp_, H_ zacatecana n_ sp_, and of different closely related Heterorhabditis species_

SpeciesLBDEPNRNLT a b C D%E%CountryReference
H. amazonensis 567-61220-2489-11576-93107-13298-11524-294.4-5.55.1-6.17.3*83-9289–109BrazilAndaló et al. (2006)
H. atacamensis 578-66619-26101-12679-101124-14494-10725-314.8-5.75.7-7.15.7*79-94149-182Chile Edgington et al. (2011)
H. bacteriophora 512-67118-3187-11072-93100-13983–11217-304.0-5.15.7-7.06.0*76-92103-130Australia Poinar (1976)
530-66022-3093-10880-90110-13084-10523*4.4*5.7*4.8*81*106*ArgentinaAgüera de Doucet and Doucet (1986)
537-58719-2287-10467-83112-12194-11125-313.3-3.63.6-4.67.0*73-8887-105Australia Sagun et al. (2015)
474-56822-28110-12761-9090-11557-9019-254.7-6.15.5-9.33.4-7.5105-139131-211IndiaBhat et al. (2019a)
453-16719-2772-10250-7483-10647-8919-294.9-7.46.0-123.7-6.578–107105-189India Rana et al. (2020)
as H. argentinensis # 610-71024-3868-11282-116101-15070-10518.3*3.7*6.5*4.3*80*141*Argentina Stock (1993)
as H. heliothidis £ 619-67123-29112*108*130-139104-11222-284.6-5.45.8-6.36.0*83*97*USA Khan et al. (1976)
H. baujardi 497-59518-2291–10375-86107-12083-9726-304.5-5.16-6.77.2*78-8898–114Vietnam Phan et al. (2003)
525-61518-2588-9668-8598-12095-10824-324.6-5.95.2-6.174-8689-92India Vanlalhlimpuia et al. (2018)
as H. somsookae # 502-56519-2381-9578-94106-11791-13123-275-54-68.0*76-8764–95Thailand Maneesakorn et al. (2015)
H. beicherriana 566-68721-25100-12285-106118-14686-11124–294.2-4.95.9-6.86.0-7.480-93103–121China Li et al. (2012)
H. downesi 588-69215-2296-12896-105126-14162-7429-424.4-5.38.5-10.54.4*76-96160-180Ireland Stock et al., 2002
H. egyptii + 484-51518-2381-9478-100100-11953-7520-274.2-5.26.8-9.16.9*74-82100-170EgyptAbd-Elgawad and Ameen (2005)
H. floridensis 554-60919-23101-12268-107123-14291-11325-323.9-4.95.3-6.67.2*71–9095–134USA Nguyen et al. (2006)
H. georgiana 547-65117-2697-11374-94110-13986-10823–344.1-5.35.5-6.96.8*70-93106USA Nguyen et al. (2008)
H. hambletoni + Brazil Pereira (1937)
H. hoptha $ USA Turco (1970)
H. indica 479-57319-2288-10772-85109-12393-10925-274.3-4.84.5-5.679-9083-103India Poinar et al. (1992)
511-54621-2492-10863–7386-10324–3422-255-64.6-5.42.8-5.277-96100-118India Kajol et al. (2020)
516-59821-2598-12382-101102-12980-11224-274.5-5.44.9-5.75.6-8.183-9793–136IndiaBhat et al. (2021b)
as H. brevicaudis # 528-63220-24104-11696-104120-13668-806.6-8.66.3*81*150-180China Liu (1994)
as H. gerrardi # 551-68218-2992-11181-105110-13076-14123-3216-2311-216.8*73-9273-138AustraliaPlichta et al.(2009)
as H. hawaiiensis # 506-63121-28116-17579-103115-18182-1086.0*77*88*USA Gardner et al. (1994)
as H. pakistanense # 558-62419-2395-10673-90113-12595-11025-294.7-5.35.4-6.25.4*78-9795-107Pakistan Shahina et al. (2017)
H. marelatus 588-70024-3281-11383-113121-13999-11721-294.7-5.45.5-6.63.0*60-8689-110USA Liu and Berry (1996)
567-78016-2488-9471-88110-11950-7131-355.1-6.510.8-11.573-88130-142USA Stock (1997)
as H. hepialius # 540-60034-3984-11280-101106-13049-605-74-59–1279-98100-200USA Stock et al. (1996)
H. megidis 736-80027-32123-142104-115147-160112–12823-384.6-5.96.1-6.96.3*81–91103-120USA (Poinar et al., 1987
H. mexicana 530-62020-2483-10974-88104-14291-10624-284.2-5.15.5-6.38.3*72-8687-111Mexico Nguyen et al. (2004)
H. noenieputensis 484-57821-2588-10569-9679-11578-9521-274.3-5.25.5-6.83.4-4.381-9599-125S. AfricaMalan et al. (2014)
H. poinari $ 350–41018-2215-22USA Kakulia and Mikaia (1997)
H. ruandica Rw14_NC4a 496-591 18-27 70-89 52-64 103-131 49-64 20-29 4.1-5.4 7.6-8.6 3.4-5.8 66-98 112-168 Rwanda This study
H. safricana 550-67619-23103-12286-101125-14186-10825-323.9-4.95.4-7.58.7*80-9099–133S. Africa Malan et al. (2008)
H. taysearae 332-49917-2374-11358-8796–13044-7018-273.4-4.26.5-8.73.7*71-96110-230Egypt Shamseldean et al. (1996)
as H. sonorensis # 495-57019-3297-11687-98110-13191-12519-264.4-5.44.0-6.56.7*78-11081-111Mexico Stock et al. (2009)
H. zealandica 570-74022-3094-12390-107135-14787-119254.96.773-92103-109N. Zealand Poinar (1990)
as H. heliothidis # 570-74022-3094-12390-107135-14787-119254.96.773-92103-109N. Zealand Wouts (1979)
H. zacatecana MEX-39 493-578 23-27 72-99 69-72 96-124 52-63 19-24 4.4-5.9 8.2-10.5 4.3–6.7 68-120 128-184 Mexico This study

Morphometrics of infective juveniles and adult generations of Heterorhabditis ruandica n_ sp_

Male
CharactersHolotypeParatypesHermaphrodite (1st Gen) paratypesFemale (2nd Gen) paratypesInfective juvenile paratypes
n120202025
Body length (L)760769 ± 60 (652-863)3295 ± 286 (2907-4123)1366 ± 123 (1131-1608)544 ± 29 (496-591)
a (L/BD)20.317 ± 1.5 (15-21)14.1 ± 1.1 (11.7-16.1)18 ± 1.4 (15-20)24 ± 3.0 (20-29)
b (L/NL)7.88.1 ± 1.0 (5.8-9.7)23 ± 1.8 (21-27)11.4 ± 1.2 (9.0-13.6)4.7 ± 0.4 (4.1-5.4)
c (L/T)26.231 ± 3.6 (23-36)42 ± 5.7 (34-51)20 ± 2.2 (16-24)8.2 ± 1.0 (7.6-8.6)
c’ (T/ABW)1.11.4 ± 0.2 (0.6-1.7)2.2 ± 0.3 (1.7-2.6)2.8 ± 0.5 (1.9-3.6)4.6 ± 0.8 (3.4-5.8)
V (VA/L × 100)48 ± 2.5 (45-55)48 ± 2.3 (41-51)
Max. Body Width (MBD)37.544 ± 3.0 (40-51)233 ± 17 (209-274)77 ± 4.0 (68-83)23 ± 2.7 (18-27)
Lip region width6.57.2 ± 0.8 (5.7-8.4)12.4 ± 0.8 (11.0-14.0)10.3 ± 0.9 (8.8-12.2)
Stoma length9.511.1 ± 1.6 (8.7-13.9)14.9 ± 1.4 (13-18)13.6 ± 1.8 (10.4-16.0)13.8 ± 1.2 (12.1-16.0)
Bulb length (BL)18.520 ± 1.8 (18-25)35 ± 3.6 (29-42)27 ± 2 (23-30)13.8 ± 1.8 (11.0-19.0)
Pharynx length (PL)95.284 ± 7.1 (74-107)128 ± 6.3 (118-142)107 ± 6.9 (91-120)102 ± 7.0 (91-115)
Nerve ring – ant. end (NR)6863 ± 5.2 (56-74)93 ± 7.5 (78-108)81 ± 6.4 (69-97)55 ± 3.6 (52-64)
Excretory pore– ant. end (EP)84.381 ± 10.1 (61-109)121 ± 11 (106-153)111 ± 10.8 (92-129)78 ± 3.4 (70-89)
Neck length (Stoma+Pharynx, NL)9896 ± 7.3 (84-117)143 ± 6.3 (134-159)120 ± 6.0 (107-132)115 ± 7.3 (103-131)
Body width at neck base3634 ± 1.9 (30-37)119 ± 8.9 (101-138)58 ± 4.3 (50-66)18 ± 3.0 (15-24)
Vagina length28 ± 4.0 (20-38)19.2 ± 2.9 (15-26)
Body width at vulva240 ± 21 (199-278)78 ± 3.8 (72-85)
Vulva – ant. end (VA)1581 ± 151 (1369-1882)655 ± 47 (572-706)
Vulva – post. End (PV)1713 ± 178 (1453-2241)710 ± 89 (559-949)
Rectum length36 ± 4.6 (29-49)30 ± 3.8 (24-35)8.5 ± 1.9 (6.1-13.7)
Anal body diam. (ABD)26.118 ± 2.4 (15-25)37 ± 5.5 (29-51)25 ± 4.5 (18-34)12.4 ± 1.8 (9.2-16.0)
Tail with sheath length (T)56 ± 4.9 (49-64)
Tail without sheath length2925 ± 3.2 (21-29)80 ± 7.9 (63-98)68 ± 6.5 (62-88)30.4 ± 4.5 (22-39)
Spicule length (SL)4943 ± 4.1 (34-50)
Gubernaculum length (GL)20.218 ± 1.5 (15-21)
Stoma length/lip region width1.51.2 ± 0.2 (1.0-1.6)1.3 ± 0.1 (1.1-1.6)
Nerve ring % (NR/NL × 100)69.467 ± 4.4 (58-75)65 ± 5.0 (56-78)67 ± 3.9 (61-75)
Excretory pore % (EP/NL × 100)8685 ± 8.5 (61-97)85 ± 8.3 (67-103)92 ± 7.6 (74-104)
Rectum % (R/ABD × 100)90 ± 10 (80-130)128 ± 29 (90-181)
D % (EP /PL × 100)88.596 ± 9.2 (69-111)95 ± 9.3 (74-114)104 ± 9.3 (82-118)78 ± 7.6 (66-98)
E % (EP/T × 100)290325 ± 49 (232-413)153 ± 24 (120-205)164 ± 23 (111-203)139 ± 13.4 (112-168)
SW % (SL/ABD × 100)242243 ± 47 (150-306)
GS % (GL/SL × 100)41.242 ± 5.2 (35-57)
H % (H/T × 10046 ± 4.0 (37–55)

Comparative morphometrics of adult females of Heterorhabditis ruandica n_ sp_, H_ zacatecana n_ sp_, and of different closely related Heterorhabditis species_

SpeciesLBDEPNRNLT a b c VABDD%CountryReference
H. amazonensis 1279-207070-122103-12668-100119-14225-382.4*46-5025-38BrazilAndaló et al. (2006)
H. atacamensis 1754-262886-129154-18279-119129-16780-1083.8*43-4924-33100-113Chile Edgington et al. (2011)
H. bacteriophora 3180-3850160-220174-21493-118155-18371-9321.4*18.841.5*3.1*42-5322-31114Australia Poinar (1976)
1800-2400100-162122-16283-102108–14540-6541-5023-40ArgentinaAgüera de Doucet and Doucet (1986)
1690-3214100-224101-21267-103120-16354-1012.4*44-5021-2472-137Australia Sagun et al. (2015)
1513-229084-150128–18171-99113–13541-7911-2211-1926-421.6–2.538-5124-39108–150IndiaBhat et al. (2019a)
1226-181958-115108-15768-91101-12729-9416-257.8-1616-481.0-3.444-5824-3183-116India Rana et al. (2020)
as H. argentinensis # 2000-350090-180105-24088-140162-20075-10812.5*7.8*31.2*2.0*42-4833-35100*Argentina Stock (1993)
as H. heliothidis £ 2000-3300184-240146*126*148-17771-9311-1514-2126-462.8*48-5333*95*USA Khan et al. (1976)
H. baujardi 1335-213090-150104-14975-122131-18568-8912-1610-1219-3246-5127-41Vietnam Phan et al. (2003)
2060-2290120-15098-11580-95123-14878-10815-1716-1820-27-41–4830-3863-78India Vanlalhlimpuia et al. (2018)
as H. somsookae # 2159-2666117-194143-15690-112128-14441-802.9*36-5121-35104-111Thailand Maneesakorn et al. (2015)
H. beicherriana 1581-3026125-21895-16559-138105-18668-10510-1810–2319–341.6-2.441-4935–8188-98China Li et al. (2012)
H. downesi 1231-272874–13199-126117-151111–15570-1222.5*47-6025-38Ireland Stock et al. (2002)
H. egyptii + 1050-142056-8469-10669-94106-12556-7817.5**14.4**22.2**3.1**44-5119-2778**EgyptAbd–Elgawad and Ameen (2005)
H. floridensis 2054-2548120-156110-16886-122126-17869-8744-5032-42USA Nguyen et al. (2006)
H. georgiana 1640-2779101-188111-17796–162136-21962-881.5*46-5342*USA Nguyen et al. (2008)
H. hambletoni + 600-120070-10080-9070-8050-58**Brazil Pereira (1937)
H. hoptha $ 2826-3983148*161*219*28*13-1912-2147-670.8*43–4933*92*New Jersey Turco (1970)
H. indica 1200-180076-113118-13888–96120-13966-8840-5322-32India Poinar et al. (1992)
1713-2242110-156135-17277-92120-13861-8313-1711-1822-361.9-2.944-5027-33102-128India Kajol et al. (2020)
1274-199370-135105-12984-111124-15564-8312-1810-1316-312.6-4.945-5222-3077-99IndiaBhat et al. (2021b)
as H. brevicaudis # 2100-2500128-168124-160100-108144-16076-9245-5336-48China Liu (1994)
as H. gerrardi # 1428-253371-161108-15773-141120-18266-953.3*43-5522-3874-112AustraliaPlichta et al. (2009)
as H. hawaiiensis # 1300-2300104-171116-17578-116110-15349-8749-5620-35USA Gardner et al. (1994)
as H. pakistanense # 1413-178571-86130-15080-100130-14565-9519-2111-1216-223.1*44-5324-2795*Pakistan Shahina et al. (2017)
H. marelatus 1600-2600113-177139-17879-119129–16455-811.3*45-5029-48110*USA Liu and Berry (1996)
USA Stock (1997)
as H. hepialius # 3500-450099-161133-17799-135150-18376–11318*13*27*1.3*49-5124-6088*USA Stock et al. (1996)
H. megidis 1500-250095-140158-206105-120155-16870-10115-1910-1618-322.6*47-5125-38119*USA Poinar et al. (1987)
H. mexicana 1144-210865-123114-14876-103121-15076-10644-5121-36Mexico Nguyen et al. (2004)
H. noenieputensis 1075-169776-129102-12573-90115-13263-7513-179-1417-242.3-3.140-5322-3283-104S. AfricaMalan et al. (2014)
H. poinari $ 910-152062-80152-17286-10511-1450-5110-1138-50USA Kakulia and Mikaia (1997)
H. ruandica Rw14_NC4a 1131-1608 68-83 92-129 69-97 107-132 62-88 15-20 9.0-14 16-24 1.9–3.6 41-51 18-34 74-104 Rwanda This study
H. safricana 1679-2937102-229151-19687–139148-18055-1111.3*45-5025-7297–120S. Africa Malan et al. (2008)
H. taysearae 830-140042-96120-16676-109129-17962-804.0*44-7319-2882*Egypt Shamseldean et al. (1996)
as H. sonorensis # 1500-250085-21095-14085-105129-21575-993.5*49-5336-4693*Mexico Stock et al. (2009)
H. zealandica N. Zealand Poinar (1990)
as H. heliothidis # N. Zealand Wouts (1979)
H. zacatecana MEX-39 1954-2798 160-228 100-133 71-96 112-148 45-75 11–15 16–21 31-63 1.3–2.0 43-61 31–41 80-111 Mexico This study

Comparative morphometrics of hermaphrodite females of Heterorhabditis ruandica n_ sp_, H_ zacatecana n_ sp_, and of different closely related Heterorhabditis species_

SpeciesLBDEPNRNLT a b c VABDD%CountryReference
H. amazonensis 3517-5587220-316184-238128-171180-225104-1542.3*42-4759-83103*BrazilAndaló et al. (2006)
H. atacamensis 1791-290488-122165-206101-132174-20072–1122.7*39-4830-4690-114Chile Edgington et al. (2011)
H. bacteriophora 3630-4390160-180189-217121-130189-20581-9341-4740-53106Australia Poinar (1976)
4200-5600175-242163-225125-152180-22050-8735-4545-62ArgentinaAgüera de Doucet and Doucet (1986)
2686-4893131-241150-37980–196162–30270-1201.8*36-5243-7676-126Australia Sagun et al. (2015)
3086-5492221-352127-26079-162101–20071-1239.2-2823-3725-751.2-3.737-5234-75112-155IndiaBhat et al. (2019a)
3916-5155205-206153-19894-127158-20770-9817-2121-2846-691.7-2.237-4639-5175-103India Rana et al. (2020)
as H. argentinensis # 5000-7500250-575250-340132-196235-300100–1401.8*40-5070-120102*Argentina Stock (1993)
as H. heliothidis £ 3000-5100200-344250*250*163-28676-10011-1811-2530-632.2*45-5262.5*80*USA Khan et al. (1976)
H. baujardi 3135-4170180-240156-192119-147186-20666-11415-1916-2136-502.0*43-4847-6388*Vietnam Phan et al. (2003)
3250-3970190-25098-115120-135180-20580-10513-1916-2031-4541-4950-6573-92India Vanlalhlimpuia et al. (2018)
as H. somsookae # 2275-3952108-183156-214118-144158-19356-872.3*41-5630-5386-113Thailand Maneesakorn et al. (2015)
H. beicherriana 3671-5543198-374165-297135-243192-34368-13013-2013-2534-621.0-2.341-4951-9276-94China Li et al. (2012)
H. downesi 3030-5051183-291200-254175-230230-24460-701.1*50-5557-65117*Ireland Stock et al. (2002)
H. egyptii + 2100-3100107-164154-205101-147144-19283-1152.7*46-5933-51104*EgyptAbd–Elgawad and Ameen (2005)
H. floridensis 3731-5865217-331211-301169-271271-39184-1262.5*44-4942-78104*USA Nguyen et al. (2006)
H. georgiana 3232-4928157-267200-277143-217132-27165-961.2*44-5542.6*USA Nguyen et al. (2008)
H. hambletoni + Brazil Pereira (1937)
H. hoptha $ USA Turco (1970)
H. indica 2300-3100107-145163-187104-123163-17972-11045-5038-51India Poinar et al. (1992)
2751-4481168-273184-238115-157167-20467-10816-1815-2535-551.4-2.537-4830-71103-132India Kajol et al. (2020)
2861-4227152-208140-179119-146165-18679-11416-2317-2430-471.5-2.439-5537-5681-100IndiaBhat et al. (2021b)
as H. brevicaudis # 3550-5040200-312160-200144-176192-24072-12837-5056-8891*China Liu (1994)
as H. gerrardi # 2049-428893-209103–28882-210146-31790-1962.4*40-4840-8090-147AustraliaPlichta et al. (2009)
as H. hawaiiensis # 4000-7000270-376219-318102-212187-28367–9838-79USA Gardner et al. (1994)
as H. pakistanense # 1939-4625102-240145-186130-180155-22064–9516–2311–2423–581.7*41-4937-5568-106Pakistan Shahina et al. (2017)
H. marelatus 3000-4500161–233212-287133-182190-24475-1011.3*45-5020-28109*USA Liu and Berry (1996)
USA Stock (1997)
as H. hepialius # 4000-5200205-335175-258117-161190-22360-1261.9*45-5034-60USA Stock et al. (1996)
H. megidis 2400-4900120-133193-270139-178106-26995-12414-2412-2123-4945-5036-86USA Poinar et al. (1987)
H. mexicana 2440-4606135-267103-201114-171168-22194-1702.6*30-5840-4690*Mexico Nguyen et al. (2004)
H. noenieputensis 2987-5498168-289152-209112-152166-22079-12014-2318-2837-581.7-3.439-4726-5677-112S. AfricaMalan et al. (2014)
H. poinari $ 1350-280054-105108-112USA Kakulia and Mikaia (1997)
H. ruandica Rw14_NC4a 2907-4123 209-274 106-153 78-108 134-159 63-98 12-16 21-27 34-51 1.7-2.6 45-55 29-51 67–103 Rwanda This study
H. safricana 3373-4073127-188210-267121-163199-23664-9143-4640-5498-119S. Africa Malan et al. (2008)
H. taysearae 2200-2800116-170137-18283–120161-20072-10040-6441-67Egypt Shamseldean et al. (1996)
as H. sonorensis # 2856-5799150-200115-203105-180133-215122-1783.0*50-5840-75-Mexico Stock et al. (2009)
H. zealandica N. Zealand Poinar (1990)
as H. heliothidis # 4000*247*181*23690*16*17*44*1.7*46*53*N. Zealand Wouts (1979)
H. zacatecana MEX-39 4408-6179 235-385 108-190 96-169 174-231 63-87 13-20 20-34 52-90 1.2-2.4 36-57 34-58 55-95 Mexico This study

Morphometrics of infective juveniles and adult generations of Heterorhabditis zacatecana n_ sp_

Male
CharactersHolotypeParatypesHermaphrodite (1st Gen) paratypesFemale (2nd Gen) paratypesInfective juvenile paratypes
n 120222225
Body length (L)808.1861 ± 29 (811-914)5127 ± 494 (4408-6179)2244 ± 203 (1954-2798)539 ± 21 (493-578)
a (L/BD)19.018 ± 1.6 (15-22)16 ± 2.0 (13-20)12.3 ± 1.2 (10.5-15.0)22 ± 1.2 (19-24)
b (L/NL)8.19.1 ± 1.1 (7.6-12)26 ± 4.3 (20-34)18 ± 1.8 (16-21)5.0 ± 0.4 (4.4-5.9)
c (L/T)28.934 ± 4.2 (26-43)70 ± 10.4 (52-90)39 ± 7.4 (31-63)9.4 ± 0.6 (8.2-10.5)
c’ (T/ABW)1.41.6 ± 0.3 (1.2-2.5)1.6 ± 0.3 (1.2-2.4)1.7 ± 0.2 (1.3-2.0)5.3 ± 0.6 (4.3-6.7)
V (VA/L × 100)48 ± 4.3 (36-57)53 ± 4.2 (43-61)
Max. Body Width (MBD)42.548 ± 3.6 (41-56)319 ± 41 (235-385)183 ± 23 (160-228)24 ± 0.9 (23-27)
Lip region width6.27.4 ± 0.7 (6.2-8.8)11.7 ± 2.4 (9.2-19.2)10.1 ± 1.0 (7.7-11.4)4.0 ± 0.5 (3.2-5.2)
Stoma length109.3 ± 1.0 (6.3-11)19 ± 2.0 (14-23)11.5 ± 1.7 (8.0-15.2)13.5 ± 1.0 (12.0-15.3)
Bulb length (BL)20.222 ± 2.4 (19-28)40 ± 4.6 (28-49)30 ± 2.6 (28-38)20 ± 1.4 (17.1-23.0)
Pharynx length (PL)95.286 ± 9.8 (57-100)182 ± 23 (155-211)113 ± 9.5 (101-133)95 ± 7.2 (82-111)
Nerve ring – ant. end (NR)65.466 ± 5.3 (60-78)131 ± 22 (96-169)83 ± 7.3 (71-96)81 ± 6.3 (69-72)
Excretory pore– ant. end (EP)96.293 ± 9.6 (77-109)150 ± 24 (108-190)113 ± 11 (100-133)89 ± 6.8 (72-99)
Neck length (Stoma+Pharynx, NL)99.396 ± 9.6 (71-108)201 ± 21 (174-231)124 ± 10 (112-148)109 ± 6.9 (96-124)
Body width at neck base34.536 ± 2.3 (31-40)167 ± 13 (133-188)95 ± 13.9 (74-121)23 ± 1.3 (19-26)
Vagina length31 ± 4.0 (24-36)25 ± 6.4 (17-42)
Body width at vulva331 ± 33 (257-379)185 ± 27 (153-230)
Vulva – ant. end (VA)2470 ± 279 (1959-3038)1182 ± 129 (910-1397)
Vulva – post. end (PV)2657 ± 279 (1990-3938)1062 ± 147 (860-1455)
Rectum length36 ± 4.6 (30-41)27 ± 4.1 (19-39)
Anal body diam. (ABD)19.617 ± 2.3 (13-22)47 ± 8.1 (34-58)35 ± 3.2 (31-41)11.1 ± 1.3 (8.6-14.1)
Tail with sheath length (T)58 ± 3.1 (52-63)
Tail without sheath length2826 ± 3.3 (21-33)74 ± 8.3 (63-87)58 ± 8.2 (45-75)29.4 ± 2.5 (25-34)
Spicule length (SL)54.145 ± 3.7 (38-55)
Gubernaculum length (GL)18.720 ± 2.1 (15-25)
Stoma length/lip region width1.61.6 ± 0.3 (1.1-2.1)1.2 ± 0.2 (0.8-1.7)
Nerve ring % (NR/NL × 100)65.969 ± 9.9 (61-96)65 ± 9.4 (49-86)67 ± 4.8 (60-82)
Excretory pore % (EP/NL × 100)96.998 ± 17 (78-134)75 ± 11 (51-95)67 ± 4.8 (60-82)
Rectum % (R/ABD × 100)79 ± 17 (54-112)76 ± 13 (52-106)
D % (EP /NL × 100)101.05109 ± 21 (83-156)75 ± 11 (55-95)92 ± 7.9 (80-111)94 ± 12 (68-120)
E % (EP/T × 100)343.6365 ± 68 (236-503)206 ± 46 (145-303)197 ± 27 (145-246)154 ± 14 (128-184)
SW % (SL/ABD × 100)276270 ± 50 (170-320)
GS % (GL/SL × 100)34.5640 ± 10 (40-60)
H % (H/T × 10047 ± 5.6 (35-56)
DOI: https://doi.org/10.21307/jofnem-2021-089 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X
Language: English
Page range: 1 - 42
Published on: Nov 11, 2021
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2021 Ricardo A.R. Machado, Aashaq Hussain Bhat, Joaquín Abolafia, Arthur Muller, Pamela Bruno, Patrick Fallet, Carla C.M. Arce, Ted C.J. Turlings, Julio S. Bernal, Joelle Kajuga, Bancy Waweru, Stefan Toepfer, published by Society of Nematologists, Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.