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Isolation, identification of entomopathogenic nematodes with insights into their distribution in the Syrian coast regions and virulence against Tuta absoluta

Open Access
|Nov 2023

Figures & Tables

Figure 1:

Distribution map of soil sample sites and entomopathogenic nematodes in Syrian coastal regions. A: Soil sample sites. B: Sites positive for entomopathogenic nematodes. Those marked with green denote H. indica, yellow denotes H. bacteriophora, blue denotes H. pakistanense, and red denotes S. affine.
Distribution map of soil sample sites and entomopathogenic nematodes in Syrian coastal regions. A: Soil sample sites. B: Sites positive for entomopathogenic nematodes. Those marked with green denote H. indica, yellow denotes H. bacteriophora, blue denotes H. pakistanense, and red denotes S. affine.

Figure 2:

Heterorhabditis indica male. A: Male entire body. B–H: Male tail with bursal papillae. B, C: Ventral view of bursa showing papillae (3–2) in the terminal group with some variation. E, F, G, H: Lateral and ventral view of bursa showing papillae (2–2) in the terminal group with some modifications (namely, being short and swollen). I: Lateral view of spicule and gubernaculum. J: Ventral view of spicule and gubernaculum. A = 705 μm. I, J: SL = 40 μm, GL = 19 μm.
Heterorhabditis indica male. A: Male entire body. B–H: Male tail with bursal papillae. B, C: Ventral view of bursa showing papillae (3–2) in the terminal group with some variation. E, F, G, H: Lateral and ventral view of bursa showing papillae (2–2) in the terminal group with some modifications (namely, being short and swollen). I: Lateral view of spicule and gubernaculum. J: Ventral view of spicule and gubernaculum. A = 705 μm. I, J: SL = 40 μm, GL = 19 μm.

Figure 3:

Heterorhabditis bacteriophora male. A: Male entire body. B: Male tail with bursal lateral view of spicules and gubernaculum. C: Lateral view of bursa showing the arrangement of papillae, arrow refers to curved outward fourth pair. D: Lateral view of bursa showing the terminal group of bursal papillae pairs (7, 8, and 9). E: Anterior portion; the left arrows refer to the ring position and excretory pore, while the right arrow refers to the end of the esophagus. A = 861 μm. B: SL = 42 μm, GL = 20 μm. E: NR = 72 μm, ES = 101 μm.
Heterorhabditis bacteriophora male. A: Male entire body. B: Male tail with bursal lateral view of spicules and gubernaculum. C: Lateral view of bursa showing the arrangement of papillae, arrow refers to curved outward fourth pair. D: Lateral view of bursa showing the terminal group of bursal papillae pairs (7, 8, and 9). E: Anterior portion; the left arrows refer to the ring position and excretory pore, while the right arrow refers to the end of the esophagus. A = 861 μm. B: SL = 42 μm, GL = 20 μm. E: NR = 72 μm, ES = 101 μm.

Figure 4:

Heterorhabditis pakistanense male. A: Male entire body. B: The anterior portion; the left arrow refers to the nerve ring position, while the right arrow refers to the excretory pore. C, D: Male tail with bursal papilae. B, C: Ventral view of bursa showing papillae (3–2) in the terminal group with some variation in tall. D: Lateral view of bursa; the arrow refers to curved outward seventh pair. E, F, G, H: Lateral and ventral view of bursa showing (2–2) papillae in the terminal group, with some modifications (namely, being short and swollen). I: Lateral view of spicule and gubernaculm. J: Ventral view of spicule and gubernaculum. A = 705 μm. I, J: SL = 40 μm, GL = 19 μm.
Heterorhabditis pakistanense male. A: Male entire body. B: The anterior portion; the left arrow refers to the nerve ring position, while the right arrow refers to the excretory pore. C, D: Male tail with bursal papilae. B, C: Ventral view of bursa showing papillae (3–2) in the terminal group with some variation in tall. D: Lateral view of bursa; the arrow refers to curved outward seventh pair. E, F, G, H: Lateral and ventral view of bursa showing (2–2) papillae in the terminal group, with some modifications (namely, being short and swollen). I: Lateral view of spicule and gubernaculm. J: Ventral view of spicule and gubernaculum. A = 705 μm. I, J: SL = 40 μm, GL = 19 μm.

Figure 5:

Evolutionary relationship of Syrian Heterorhabditis isolates using ITS rDNA sequences. The evolutionary history was inferred by using the maximum likelihood method. The bootstrap consensus tree inferred from 1,000 replicates is taken to present the evolutionary history of the analyzed taxa. Caenorhabditis elegans was used as an outgroup.
Evolutionary relationship of Syrian Heterorhabditis isolates using ITS rDNA sequences. The evolutionary history was inferred by using the maximum likelihood method. The bootstrap consensus tree inferred from 1,000 replicates is taken to present the evolutionary history of the analyzed taxa. Caenorhabditis elegans was used as an outgroup.

Figure 6:

Cluster dendrogram of Syrian Heterorhabditis species isolates based on male morphological traits.
Cluster dendrogram of Syrian Heterorhabditis species isolates based on male morphological traits.

Figure 7:

Co-inertia loading plot for EPN species and habitat and abiotic factors data in the Syrian coastal ecosystems surveyed.
Co-inertia loading plot for EPN species and habitat and abiotic factors data in the Syrian coastal ecosystems surveyed.

Figure 8:

Larvae and pupae of T.absoluta infected by S.affine M.313. A: S. affine after completing its development within the fourth-instar larva. B: Emergence of the IJs from the infected fourth instar larva. C: Infected third instar larva. D, E: S.affine female inside pupae observed with the naked eye and 4× magnification.
Larvae and pupae of T.absoluta infected by S.affine M.313. A: S. affine after completing its development within the fourth-instar larva. B: Emergence of the IJs from the infected fourth instar larva. C: Infected third instar larva. D, E: S.affine female inside pupae observed with the naked eye and 4× magnification.

Figure 9:

Larvae and pupae of T.absoluta infected by H.indica H. A, B: infected fouth-instar larvae outside leaf and inside mine. C, D: Infected third-instar larva outside leaf, and hermaphroditic inside it. E: Infected pupae. F: Hermaphroditics inside pupa.
Larvae and pupae of T.absoluta infected by H.indica H. A, B: infected fouth-instar larvae outside leaf and inside mine. C, D: Infected third-instar larva outside leaf, and hermaphroditic inside it. E: Infected pupae. F: Hermaphroditics inside pupa.

Figure 10:

Mortality rates (mean ± SD) of third- and fourth-instar larvae inside the galleries and pupae of T.absoluta treated by LD50 inoculation rates of S.affine and H.indica (P = 0.01).
Mortality rates (mean ± SD) of third- and fourth-instar larvae inside the galleries and pupae of T.absoluta treated by LD50 inoculation rates of S.affine and H.indica (P = 0.01).

Morphometrics of male of the Syrian Heterorhabditis indica isolates_ All measurements are in μm (except n, ratio, and percentage), and in the form mean ± S_D_ (range)_

CharacterSY-BSSY-ESY-ASSY-KSY-BOSY-FASY-SHSY-HRSY-KASY-ZSY-MSSY-MESY-HWSY-AFH. indica Type strain Poinar et al. (1992)
n202020202020202020202020202012
L685±89 (569–719)697±80 (598–731)689±75 (604–740)715±69 (591–730)703±81 (590–741)718±87 (610–773)726±89 (598–761)741±91 (589–767)735±85 (602–759)749±80 (584–773)738±90 (609–770)745±77 (614–780)754±94 (598–783)762±79 (590–790)721 (573–788)
MBD37±2.3 (35–41)38.5±2.4 (35–43)37±2.1 (33–40)41±1.5 (38–47)40.5±1.8 (37–43)41±1.3 (37–42)41.5±1 (35–44)42±1.2 (37–45)42±1.9 (35–44)43.5±1.6 (38–47)43±0.9 (37–44)44±1.4 (38–46)43.5±1.5 (36–45)43±1.9 (38–45)42 (35–46)
EP113±6.7 (105–125)114.5±5.9 (107–121)114±6.1 (107–127)119±8.1 (107–127)115.5±5.7 (109–125)119±5.9 (105–130)124±5.1 (109–131)126±5.5 (110–137)124.5±5.9 (105–134)126±5.8 (114–136)124.5±6.1 (107–133)126.5±5.4 (112–136)129±5.8 (110–139)132±6 (109–140)123 (109–138)
NR71±4.5 (69–76)72±5.8 (69–79)71.5±4.3 (67–75)74±4.7 (70–80)72±6.1 (68–83)73±5.7 (69–84)73±4.1 (70–80)78±5.5 (69–80)77.5±4.3 (70–81)78.5±4.9 (70–85)77±3.9 (73–83)78±4.5 (72–84)79±5.1 (74–86)78.5±5.2 (71–85)75 (72–85)
ES95±5.7 (94–104)97.5±5.1 (92–103)95.5±5.5 (93–105)98±5.9 (92–107)98.5±6.1 (94–107)99±6.3 (95–108)101±5.8 (95–107)103±5.9 (94–106)101.5±6 (96–109)104±5.8 (94–107)103±5.2 (96–105)103.5±4.9 (95–106)104.5±5.6 (94–109)106±6 (97–109)101 (93–109)
ABW20±1.2 (18–22)20±1.3 (17–21)20.5±1.2 (18–23)20±1.4 (17–23)21±0.9 (18–24)22±1.3 (19–24)22.5±1.4 (18–24)23±0.8 (19–24)22±1.4 (19–25)23±1.1 (17–25)21.5±0.9 (19–24)22.5±1.4 (18–25)23.5±1.2 (18–25)23±1.1 (18–25)23 (19–24)
T23±2.1 (21–26)25±1.9 (22–29)24.5±1.3 (23–30)26±1.7 (21–30)25±1.8 (22–30)26.5±2.3 (24–33)27.5±2.1 (24–31)29±2.6 (21–32)29±2 (24–31)30±2.5 (22–32)28±2.1 (24–31)29.5±1.9 (24–32)30±1.6 (24–31)30±1.5 (25–33)28 (24–32)
a18.5117.918.6117.4317.3517.5117.4917.6417.517.2116.916.9317.3317.717.16
b7.217.147.217.297.137.257.187.197.247.207.167.197.217.187.13
c29.727.8828.127.528.122727.3925.525.3425.8226.325.2525.1325.425.75
D1.181.171.191.211.161.201.221.221.221.211.201.221.231.241.21
E4.914.584.634.64.54.494.504.344.294.24.444.284.34.44.39
SL37±3.9 (34–43)38.5±3.7 (35–44)37±3.5 (35–43)41±4 (37–42)39.5±3.2 (38–44)42±2.1 (39–46)43±3.1 (37–46)44.5±3.4 (38–47)43.5±3.2 (39–45)45±3.9 (38–47)44±3.1 (40–48)44.5±3.2 (40–47)46±3.8 (39–48)47.5±4.1 (39–50)43 (35–48)
GL17.5±1.9 (17–22)19±1.5 (17–22)18±1.3 (17–21)21±1.7 (19–22)19.5±1.2 (18–22)20.5±1.3 (19–23)21±1.4 (17–22)21.5±1.3 (19–22)22±1.2 (19–23)23±1.6 (19–25)21±1.2 (20–24)22±1.6 (19–23)22.5±1.4 (19–24)23±1.2 (18–24)21 (18–22)
SW1.851.921.8021.881.901.911.931.891.9521.971.9521.86
GS0.470.490.480.510.490.480.480.480.500.510.470.490.480.480.50 (0.40–0.60)

Morphometrics of male of the Syrian Heterorhabditis bacteriophora isolates_ All measurements are in μm (except n, ratio, and percentage), and in the form: mean ± s_d_ (range)_

CharacterSY-ALSSY-SRSY-ALBSY-ALSY-KSY-SSY-DSY-ZSY-BH. bacteriophora Type strain Poinar (1976)
n20202020202020202015
L845±91 (789–910)829±85 (778–903)810±65 (785–895)819±69 (791–901)824±84 (775–915)831±95 (793–942)804±79 (773–891)820±83 (786–900)815±74 (781–906)820 (780–960)
MBD46.5±4.8 (37–48)44.5±5.1 (39–47)41±4.1 (36–43)41±4.5 (38–46)42.5±4.6 (37–47)44.5±4.1 (39–46)40±4.2 (35–45)42±4 (36–45)41±4.3 (36–45)43 (38–46)
EP126±5.5 (115–129)124±5.7 (114–126)119.5±5.1 (115–125)121.5±5.5 (115–125)123±5.9 (115–128)124.5±5.8 (115–130)120±5.9 (112—124)122.5±5.1 (116–128)122±5.4 (114–129)121 (114–130)
NR76±4.7 (67–79)73±4.6 (64–77)69±4.1 (67–74)71±4.5 (67–77)72±5.1 (65–80)73.5±5.2 (66–83)68.5±4 (65–75)71.5±4.3 (67–76)71±4.7 (66–78)72 (65–81)
ES103.5±2.1 (100–104)103±2 (99–104.5)102±1.7 (99–104)101±1.1 (100–103)102.5±1.2 (98–104)103±1.2 (99–104)100±0.8 (98–102)101±0.9 (99–103)100.5±1 (97–104)103 (99–105)
ABW24.5±1.7 (22–26)23±1.3 (21–24)21±1.1 (20–23)21.5±1.5 (20–24)23±1.2 (21–24)23.5±1 (21–25)21±0.9 (20–23)23±1.4 (20–24)21±1.1 (20–24)23 (22–25)
T32.5±3.9 (24–34)29±4.3 (22–32)25±3.8 (24–30)26.5±3.1 (24–31)27±4.1 (22–34)29.5±3.5 (24–35)23.5±4.5 (21–30)27±3.4 (24–30)26±3.1 (24–31)28
a18.118.619.719.919.318.62019.519.819
b8.168.047.948.108.038.068.048.118.017.9
c25.2228.5832.530.930.528.1624.7330.331.3429.2
D1.211.201.171.201.21.201.21.211.211.17
E3.764.274.784.584.554.225.14.534.694.32
SL42.5±2.5 (37–44)40±2.6 (35–43)37.5±2 (36–41)39±1.7 (37–44)39.5±1.8 (36–44)41±2.9 (36–46)37±2 (35–42)39±1.7 (36–42)39±1.6 (35–42)40 (36–44)
GL21±0.8 (19–23)19±0.7 (18–23)18±0.7 (17–22)19±0.9 (18–23)20±1 (17–23)21±1.1 (18–24)19±1 (17–22)20±1.2 (17–23)19±1.1 (17–23)20 (18–25)
SW1.731.731.781.811.711.741.761.691.851.74
GS0.490.470.480.480.480.510.510.510.480.50

Morphometrics of infective juvenile and male of the Syrian Heterorhabditis pakistanense isolates_ All measurements are in μm (except n, ratio, and percentage), and in the form mean ± S_D_ (range)_

CharacterHeterorhabditis pakistanense SY-BHHeterorhabditis pakistanense SY-ZOHeterorhabditis pakistanense n. sp. (Shahina et al., 2016)



StageInfective JuvenileMaleInfective JuvenileMaleInfective JuvenileMale
n202020202525
L575±23 (536–597)839.5±91 (710–945)583±31 (542–603)810±85 (721–991)581 (558–624)819 (720–1013)
MBD20±2.7 (17–21)39.5±2.4 (36–41)19±0.8 (17–22)38±2.1 (35–40)21 (19–23)39.8 (38–43)
EP95.5±3.6 (85–98)120.4±3.2 (113–129)92±2.7 (87–98)119±3.4 (114–125)99.3 (95–106)122.8 (112–133)
NR83±2.5 (70–89)87±3.8 (81–97)81±1.5 (73–86)85.6±4.2 (79–95)82 (73–90)89 (80–110)
ES116.5±2.9 (109–121)100.5±1.1 (97–103)114±1.6 (107–119)98.5±0.9 (97–101)117 (113–125)102 (100–105)
ABW12.5±1.5 (9.4–15)23.3±0.9 (21–25)12±1.2 (10–15)22.5±1.4 (21–26)13.7 (12–16)24.5 (22–26)
T96.5±2.3 (92–103)38±1.8 (32–41)94±2.1 (90–105)35.5±2.3 (31–40)99 (95–110)37 (30–42)
a28.7521.230.621.327.4 (25–29)20.5 (18–23.5)
b4.98.355.118.224.8 (4.7–5.3)7.9 (7.2–9.8)
c5.95226.222.85.78 (5.4–6.2)22 (19.3–25)
D0.811.190.801.200.84 (0.78–0.97)1.19 (1.1–1.26)
E0.983.160.973.351 (0.95–1.07)3.31 (2.67–4)
SL-39±2.4 (35–41)-37±2.7 (34–40)-38.5 (35–42)
GL-21.4±1.9 (19–23)-20.5±1.5 (19–22)-21 (20–22)
SW-1.67-1.64-1.56 (1.44–1.91)
GS-0.54-0.55-0.58 (0.48–0.65)

Locality, coordinates, altitude, sampling date, habitat, and soil characteristics of positive samples_

SpeciesSite/LocationGenBank accession no.CoordinatesAltitudeSampling dateHabitatsSoil typespHOrganic matter %
H. indicaZeghreen / LatakiaOP22199335°43′39″N 35°52′39″E40 mAutumnOlive fieldSandy7.33.39
H. indicaAl-Hinadi / LatakiaOP22198835°51′48″N 35°30′12″E36 mAutumnCitrus orchardSilty loam7.51.4
H. indicaEin-Albida / LatakiaOP22198735°39′26″N 35°35′18″E207 mAutumnCitrus orchardSilty loam7.55.19
H. indicaAl-Meherfha/LatakiaOP22199235°36′12″N 35°51′20″E214 mAutumnOlive orchardSandy loam6.12.3
H. indicaAl-Shamiea /LatakiaOP22198935°38′22″N 35°48′30″E61 mAutumnCitrus orchardSilty loam6.53.72
H. indicaFattiro /LatakiaOP22199135°37′19″N 35°15′24″E138 mAutumnOlive orchardClay6.22
H. indicaKersana/LatakiaOP22198335°37′18″N 35°49′40″E53 mAutumnOlive orchardSandy loam6.05.72
H. indicaAl-Basa/LatakiaOP22198435°30′14″N 35°52′15″E46 mAutumnVegetablesSilty loam6.52.33
H. indicaAl-Borjan /LatakiaOP22198635°17′34″N 35°58′42″E47 mAutumnVegetablesSandy loam6.13.66
H. indicaAl-Meghreet /LatakiaOP22199035°63′17″N 35°49′53″E81 mSpringCitrus orchardSilty loam6.42.9
H. indicaAl-Hwiz/LatakiaOP22199635°20′27″N 36°00′02″E108 mSpringGrasslandSandy loam5.22.26
H. indicaHraeson / TartusOP22198535°15′01″N 35°57′01″E15 mSpringCitrus orchardSilty loam8.12.73
H. indicaFneiteq /TartusOP22199435°06′51″N 36°07′17″E597 mAutumnWalnut orchardSilty loam8.11.73
H. indicaKarm-Alten/TartusOP22199535°07′01″N 36°06′20″E580 mSpringGrasslandSandy7.53.02
H. bacteriophoraAl-Snobr /LatakiaOP22291635°28′45″N 35°53′09″E26 mSpringGrasslandClay loam5.86.2
H. bacteriophoraZeghreen /LatakiaOP22202035°43′45″N 35°52′57″E46 mAutumnCitrus orchardClay loam6.74.72
H. bacteriophoraAl-Shelfatea/LatakiaOP22201935°32′54″N 35°53′53″E41 mAutumnCitrus orchardSilty loam7.13.3
H. bacteriophoraAl-Serskiea/LatakiaOP22201835°42′33″N 35°55′36″E85 mAutumnVegetablesSandy loam6.75.39
H. bacteriophoraRas-Alein /LatakiaOP22201535°17′38″N 35°57′53″E32 mSpringTobacco fieldSilty loam6.01.46
H. bacteriophoraAl-Basa /LatakiaOP22201735°29′34″N 35°50′43″E4 mAutumnCitrus orchardSilty loam7.72.67
H. bacteriophoraDimsarkho /LatakiaOP22201235°33′07″N 35°46′26″E15 mAutumnTobacco fieldSilty loam5.93.06
H. bacteriophoraAL-Kawkae/TartusOP22201435°09′24″N 36°06′47″E486 mSpringGrasslandClay loam6.32.06
H. bacteriophoraBet-shofan /TartusOP22201334°45′35″N 36°00′44″E70 mSpringCitrus orchardSilty loam7.81.25
H. pakistanenseAl-Zobar /LatakiaOP23551435°37′57″N 36°00′12″E213 mAutumnPear orchardSandy loam6.81.86
H. pakistanenseAl-Bahloliea/LatakiaOP23551335°38′09″N 35°57′40″E179 mSummerVineyardSandy loam7.11.3
S. affineAmodeyha/TartusOM35011935°06′10″N 36°07′57″E759 mSpringWalnut orchardSilty loam6.16
S. affineFneitiq/TartusOL43701635°06′02″N 36°08′51″E604 mWinterGrass landSilty6.44.1

Vegetation habitat and abiotic factors with their corresponding codes_

HabitatCode-HabSoil characteristicsCodeAltitude and SeasonCode
Citrus orchardHab1Soil type
  • C

  • Sa

  • Si

  • SaL

  • SiL

  • CL

Altitude
  • Alt1

  • Alt2

  • Alt3

  • Alt4

Olive orchardHab2
  • Clay

  • Sand

  • Silty

  • Sandy loam

  • Silty loam

  • Clay loam

  • 0–200 m

  • 200–400 m

  • 400–600 m

  • 600–800 m

GrasslandHab3
VegetablesHab4Season
Walnut orchardHab5
  • pH

  • <6.5

  • = 6.5–7.5

  • >7.5

  • pH1

  • pH2

  • pH3

  • Autumn

  • Spring

  • Summer

  • Winter

  • S1

  • S2

  • S3

  • S4

Tobacco fieldHab6
Pear orchardHab7
  • Organic matter content

  • 1–2%

  • 2–4%

  • 4–6%

  • OM1

  • OM2

  • OM3

VineyardHab8

Morphometrics of infective juvenile of the Syrian Heterorhabditis bacteriophora isolates_ All measurements are in μm (except n, ratio, and percentage), and in the form mean ± S_D_ (range)_

CharacterSY-ALSSY-SRSY-ALBSY-ALSY-KSY-SSY-DSY-ZSY-BH. bacteriophora Type strain Poinar (1976)
n20202020202020202015
L603±80 (532–613)600±67 (521–611)597±71 (527–608)589±67 (529–603)593±78 (522–610)578±79 (524–602)553±51 (519–597)564±63 (520–602)575±59 (518–590)588 (512–617)
MBD26±3.2 (18–33)26±3 (17–31)24.5±2.8 (18–29)24±2.9 (18–31)24±2.9 (18–33)23.5±2.8 (18–31)21.5±3.1 (18–29)23±3.3 (18–31)23±2.7 (18–31)23 (18–31)
EP106.5±5.4 (91–112)106±5.6 (86–114)105.5±6 (89–109)102±6.3 (85–105)104±6.8 (89–110)98.5±5.7 (87–102)93.5±5.1 (88–100)94.5±5 (89–101)97±5.5 (88–100)103 (87–110)
NR90±4.8 (75–95)88.5±4.5 (72–92)88.5±4.6 (72–90)86.5±4.9 (74–90)88±4.7 (71–94)84±5 (72–90)80.5±4.3 (70–91)84±4.6 (71–92)83±4.2 (70–89)85 (72–93)
ES132±6.2 (113–138)131.5±5.7 (103–135)129.5±5.9 (102–135)126.5±6.1 (105–130)128±6.3 (104–138)124±6 (102–132)114±5.9 (104–130)119±5.6 (107–130)122±6.2 (106–129)125 (100–139)
ABW8.2±1.2 (6–8)8±1.1 (6.3–8.4)7.8±0.9 (6.5–8)7.4±0.7 (6.5–7.9)7.5±1 (6.5–8)7.2±0.7 (6.3–7.9)6.5±0.9 (6.2–7.4)6.8±0.9 (6.5–7.8)7±1 (6–7.4)-
T108.5±6.7 (89–115)107±6.4 (81–114)104±6.1 (83–109)100±5.8 (85–104)102±6.2 (81–112)95±6.3 (82–101)89±6 (81–100)92.5±5.6 (82–102)93.5±5.1 (81–98)98 (83–112)
a23.12324.3624.524.724.5925.7224.522525 (17–30)
b4.564.564.614.654.634.664.854.734.714.5 (4–5.1)
c5.555.605.745.895.8166.2166.146.2 (5.5–7)
D0.800.800.810.800.830.790.820.790.790.84 (0.76–0.92)
E0.980.991.011.0211.031.051.021.031.12 (1.03–1.30)

Mortality of third- and fourth-instar larvae of Tuta absoluta on outside leaves at each dose rate for three different entomopathogenic nematodes (mean ± S_D_)_

EPNs speciesDose 1IJ/ LDose 5Ij/ LDose 10Ij/LDose 15Ij/ LDose 25Ij/ LDose 50Ij/ L
Third-instar larvae of T. absolutaS. affine. 31325.00a±1.6237.50a±2.1645.83a±1.3354.17a±1.4566.67a±079.17a±0.95
H. indica. Fn16.67b±026.17ab±2.2737.50a±1.3345.83a±1.4562.50a±1.4370.83a±0.84
H. bacteriophora. H8.33bc±0.3216.67bc±0.1525.00b±2.6233.33b±037.50b±1.4345.83b±0.84
Control0c±00c±00c±00c±00c±00c±0
P=0.00139**P=0.0000657***P=0.0000114***P=0.0000105***P=0.0000559***P=0.0000011***
df= 3df= 3df=3df=3df=3df=3
F=10F=30.7F=27.6F= 65.33F=108.5F=97.22

Fourth-instar larvae of T. absolutaS. affine. 31329.17a±1.3341.67a±1.6450.0a ±059.52a±1.1671.43a±1.5991.67a±1.62
H. indica. Fn20.83ab±1.3336.50ab±1.3341.67ab±1.6250.0ab±050.00a±1.4587.50a±1.33
H. bacteriophora. H12.50ab±2.1725.00b±1.6433.33b±041.67b±1.6245.83a±1.3354.17b±1.95
Control4.17b±1.624.17c±1.344.17c±1.334.17c±1.334.17b±1.334.17c±1.33
P=0.00671**P=0.000318***P=0.0000175***P=0.0000462***P=0.00295**P=0.0000311***
df= 3df= 3df= 3df= 3df= 3df= 3
F=6.67F=14F=39.29F=32.78F=8.29F=53.86

Distribution of EPNs in Syrian coast region according to the vegetation habitat, altitude and sampling seasons variables_

HabitatFrequencyAbundanceNo. of identified samples to species
Coniferous forest0 c0 b0
Broadleaf forest0 c0 b0
Citrus orchards27.27 a2.4 a9
Olive orchards10.81b1.06 a4
Walnut orchards8 b0.53 a2
Pear orchards4.34 b,c0.26 a1
vineyard4 bc0.26 a1
Fruit orchards (e.g., cherry, apple)0 c0 b0
Vegetable fields7.5 b0.8 a3
Oil crop0 c0 b0
Leguminous crop0 c0 b0
Leafy vegetables0 c0 b0
Tobacco fields8.33b0.53 a2
Riverbanks0 c0 b0
Greenhouses0 c0 b0
Fodder crop0 c0 b0
Grassland11.11b1.33 a5
Medicinal and aromatic plants0 c0 b0
Sea coast0 c0 b0
Public parks0 c0 b0
P = 0.01491P = 0.01892
Altitude
0–2008.37a19.3118
200–4001.79b3.793
400–6001.93b3.943
600–8001.39b2.72
>8000c00
P = 0.0138P = 0.1565
Season
Autumn5.01 a10.3716
Spring2.4a,b6.339
Summer1.4b1.961
Winter1.78 b2.121
P = 0.0474P = 0.08053

Morphometrics of infective juvenile of Syrian Heterorhabditis indica isolates_ All measurements are in μm (except n, ratio, and percentage), and in the form: mean ± s_d_ (range)_

CharacterSY-BSSY-ESY-ASSY-KSY-BOSY-FASY-SHSY-HRSY-KASY-ZSY-MSSY-MESY-HWSY-AFH. indica Type strain Poinar et al. (1992)
n202020202020202020202020202025
L532±31 (503–589)551±25 (532–591)547±45 (523–598)559±37 (518–589)553±37 (510–595)561±41 (529–602)569±27 (520–596)578±46 (545–610)570±21 (531–604)589±69 (520–610)597±51 (532–614)602±62 (541–610)607±66 (539–615)604±59 (551–618)528 (479–573)
MBD20.5±0.7 (18–22)20±1.1 (19–23)19±0.8 (17–21)19.5±0.9 (18–22)20 ±1 (18–21)21±1.3 (17–24)21±1.2 (18–23)22±1.4 (18–24)21.5±1.5 (19–24)21±1.2 (18–25)22±1.4 (17–24)21±1.8 (18–26)22±1.2 (19–25)22±1 (18–25)20 (19–22)
EP97.2±6 (85–103)95±5.5 (83–101)94.5±5.3 (85–100)96.5±5 (87–102)94±4.9 (82–102)96±5.2 (83–102)101±6.1 (85–107)98.5±4.7 (87–103)101±4.5 (81–105)102±6.7 (89–107)102±6.4 (84–106)101.5±58 (89–110)103±6.5 (87–112)102±6.3 (89–109)98 (88–107)
NR81.4±3 (70–86)78.6±2.4 (74–87)83±1.9 (78–88)82.5±2.1 (73–86)82±2.3 (75–84)81±2.8 (70–85)83±2.7 (74–88)80±2.3 (75–86)82.5±2.2 (73–85)84±2.6 (74–88)83.5±2.9 (71–87)84±2.5 (75–88)81±2.7 (72–86)80.5±2.9 (75–84)82 (72–85)
ES118±4 (112–122)117±5.1 (104–123)118±6 (109–121)117.5±5 (110–120)115±5.6 (109–121)121±5.4 (110–123)121±5.8 (112–124)122±7.4 (105–125)118±6.1 (107–120)119.5±6 (107–122)120±6.1 (114–125)119±5.4 (108–121)118±5.7 (110–123)120±5.5 (109–122)117 (109–123)
ABW9.6±1.1 (8–11)7±0.7 (6.5–8)7.1±0.8 (6.5–7.8)7±0.7 (6.4–7.5)6.7±1 (6.2–7.5)7.2±0.8 (6.5–7.9)7.5±0.9 (6.7–7.9)7.2±0.4 (6.8–7.5)7±0.6 (6.4–7.6)7.8±0.9 (6.9–8)6.8±0.8 (6.4–7.8)6.7±0.9 (6.5–7)7.1±0.5 (6.7–7.4)7±0.5 (6.5–7.6)-
T103±5.1 (88–105)94±2.3 (90–97)96±4.1 (92–106)97.5±2.3 (93–102)97±1.4 (92–99)98.5±2.9 (89–103)95±2.1 (90–101)102±5 (89–107)98±4.9 (88–105)101±4.1 (90–110)98.5±4.5 (93–104)102±4 (94–107)104±4.3 (93–105)101±4.9 (95–107)101 (93–109)
a25.927.528.728.627.626.72726.226.52827.127.327.527.426 (25–27)
b4.504.74.634.754.824.634.704.814.834.904.9755.1454.5 (4.3–4.8)
c5.15.865.695.735.705.695.985.665.815.8365.905.835.985.3 (4.5–5.6)
D0.820.810.800.820.820.790.830.800.850.850.850.850.870.850.84 (0.79–0.90)
E0.941.010.980.980.960.971.060.961.0311.030.990.9910.90 (0.83–1.03)
DOI: https://doi.org/10.2478/jofnem-2023-0056 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X
Language: English
Submitted on: May 18, 2023
Published on: Nov 30, 2023
Published by: Society of Nematologists, Inc.
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year

© 2023 Mai Ali, Nada Allouf, Mohammad Ahmad, published by Society of Nematologists, Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.