Table 2 Descriptive statistics, the coefficient of variation (CV) and Mayr’s coefficient of difference (CD) for 15 measurements and eight ratios of morphometric parameters in two Culicoides species (C. obsoletus and C. scoticus). The 758 Culicoides were trapped in the UK, France and Spain

Wing length

1.27 (0.16)

12.26

1.34 (0.15)

11.32

0.22

Wing width

0.56 (0.26)

47.02

0.58 (0.06)

11.05

0.04

Costa length

0.80 (0.10)

12.8

0.83 (0.10)

12.36

0.15

Wing ratio

2.32 (0.15)

6.35

2.33 (0.06)

2.6

0.05

Costa ratio

1.59 (0.04)

2.23

1.61 (0.04)

2.38

0.35

Third palp length

51.94 (6.95)

13.39

51.67 (7.08)

13.7

0.02

Third palp width

21.47 (3.35)

15.61

17.87 (2.92)

16.32

0.57

Palpal ratio

2.46 (0.39)

15.68

2.96 (0.61)

20.42

0.51

Flagella 10 length

37.12 (3.61)

9.72

35.89 (3.72)

10.37

0.17

Flagella 11 length

49.32 (5.32)

10.78

50.33 (5.10)

10.12

0.10

5 Apical segment length

298.30 (26.52)

8.89

299.85 (25.36)

8.46

0.03

8 Basal segment length

271.94 (23.76)

8.74

259.02 (20.94)

8.08

0.29

Flagella ratio

1.10 (0.05)

4.62

1.16 (0.07)

6.24

0.50

Segment ratio

1.33 (0.11)

8.06

1.41 (0.14)

9.96

0.31

Larger spermatheca length

47.89 (1.74)

3.63

61.64 (2.18)

3.54

3.51

Larger spermatheca width

33.26 (1.47)

4.43

41.19 (2.48)

6.03

2.00

Smaller spermatheca length

47.29 (1.31)

2.77

61.03 (1.88)

3.09

4.30

Smaller spermatheca width

32.83 (1.59)

4.84

40.35 (2.80)

6.93

1.72

Larger spermatheca ratio

1.44 (0.07)

4.84

1.50 (0.10)

6.66

0.35

Smaller spermatheca ratio

1.44 (0.07)

4.87

1.52 (0.11)

7.37

0.42

Length between chitinous plates

11.91 (1.60)

13.41

20.25 (5.84)

28.85

1.12

Width of chitinous plates

18.31 (2.08)

11.37

20.68 (2.73)

13.18

0.49

Chitinous plate ratio

0.66 (0.10)

15.86

0.99 (0.31)

31.23

0.81