Table 1 Morphometrics of all generations of Steinernema abbasi CS38. All measurements are in μm (except n, ratio and percentage) and in ± SD (range)

Body length (L)

1270 ± 111 (1082–1441)

883 ± 69 (761–1006)

5041 ± 792 (3731–6314)

1631 ± 237 (1287–2071)

581 ± 20 (520–610)

Excretory pore (EP)

72 ± 8.6 (57–83)

62 ± 3.5 (54–68)

80 ± 7.6 (70–96)

55 ± 4.0 (46–60)

46 ± 3.3 (39–53)

Width EP (WEP)

51 ± 6.4 (41–62)

30 ± 1.2 (29–33)

81 ± 6.4 (70–88)

43 ± 4.9(34–52)

18 ± 1.0 (16–20)

Nerve ring (NR)

91 ± 8.3(81–114)

72 ± 5.1 (63–85)

102 ± 10 (92–127)

75 ± 3.2 (71–81)

57 ± 6.4 (42–67)

Pharynx length (ES)

138 ± 9.1 (121–162)

118 ± 5.9 (107–126)

169 ± 8.0 (159–190)

134 ± 4.5 (125–140)

88 ± 7.3 (69–98)

Esophageal bulb length

29 ± 3.3(23–35)

25 ± 2.5(20–31)

43 ± 4.4(35–54)

31 ± 3.5(26–39)

16 ± 1.4 (14–19)

Esophageal bulb width

24 ± 1.8 (20–27)

21 ± 1.7 (19–25)

33 ± 2.9 (28–38)

26 ± 1.9 (23–30)

11 ± 1.4 (8–13)

Tail (T)

22 ± 2.7 (16–27)

18 ± 1.4 (15–20)

47 ± 11 (29–72)

44 ± 8.2(26–56)

55 ± 4.9 (42–63)

Anal body width (ABW)

35 ± 3.4 (29–41)

28 ± 1.5 (26–30)

67 ± 16 (41–95)

35 ± 5.8 (28–48)

14 ± 1.3 (12–17)

Body dia. (BD)

135 ± 14 (101–156)

60 ± 5.2 (54–73)

205 ± 20 (169–239)

95 ± 19 (69–130)

26 ± 1.6 (22–30)

Testis reflection (TR)

241 ± 26 (186–282)

74 ± 6.3 (63–84)

Spicule length (SL)

72 ± 4.5 (62–80)

53 ± 7.7 (33–63)

Gubernaculum length (GL)

46 ± 2.8 (42–50)

37 ± 2.6 (30–40)

Anterior to vulva

2676 ± 428 (2136–3299)

891 ± 124 (710–1080)

Posterior to vulva

2386 ± 413 (1571–3015)

740 ± 128 (540–996)

Width at vulva (WV)

194 ± 24 (161–229)

102 ± 19 (72–136)

a = L/GBW

9.5 ± 1.1(7.5–11)

15 ± 1.6 (12–17)

25 ± 5.6 (17–37)

17 ± 1.4 (15–19)

23 ± 1.7 (20–25)

b = L/ES

9.2 ± 0.8 (8.1–11)

7.5 ± 0.6 (6.2–8.6)

30 ± 4.2 (22–37)

12 ± 1.6 (10–16)

6.7 ± 0.4 (6.0–7.5)

c = L/Tail

58 ± 10 (46–83)

50 ± 3.4 (43–54)

113 ± 29 (55–173)

38 ± 6.9 (27–50)

11 ± 1.1 (9.2–13.6)

c' = Tail/ABW

0.6 ± 0.1 (0.5–0.7)

0.6 ± 0.0(0.5–0.7)

0.7 ± 0.1 (0.5–0.9)

1.3 ± 0.3 (0.9–1.8)

3.8 ± 0.4 (3.2–4.8)

D% = EP/ES × 100

52 ± 4.9 (44–60)

53 ± 2.1 (48–56)

47 ± 3.6 (42–55)

41 ± 3.0 (34–46)

53 ± 3.7 (45–58)

E% = EP/Tail×100

325 ± 42 (248–403)

350 ± 36 (294–438)

180 ± 42 (97–237)

129 ± 29 (89–201)

85 ± 8.7 (70–102)

F% = GBW/Tail×100

619 ± 111 (427–875)

338 ± 39 (285–409)

457 ± 103(321–677)

218 ± 45 (154–305)

47 ± 5.5 (36–64)

V = V'/L × 100

53 ± 2.7 (47–58)

55 ± 2.6 (50–59)

SW%

210 ± 25 (159–245)

191 ± 26 (114–220)

GS%

65 ± 6.3 (58–80)

70 ± 9.2 (57–91)

EP/WEP

1.4 ± 0.2 (0.9–1.7)

2.1 ± 0.1 (1.8–2.3)

1.0 ± 0.1 (0.8–1.2)

1.3 ± 0.2 (1.1–1.6)

2.5 ± 0.2 (2.1–3.0)

EBL/EBW

1.2 ± 0.1 (1.1–1.4)

1.2 ± 0.1 (1.0–1.3)

1.3 ± 0.1 (1.1–1.5)

1.2 ± 0.1 (1.0–1.4)

1.6 ± 0.2 (1.1–2.1)