Table 5 Partitioning total diversity (Shannon–Weaver index, H) for field-collected S. avenae populations during 1997 (Shufran and Wilde, 1994)

Rothamsted A

2.694

Rothamsted B

2.237

2.867

Hemel A

2.220

Hemel B

2.239

2.667

Garford A

2.474

Garford B

1.034

2.115

2.965

Mean diversity

H_field=2.150

H_farm=2.550

H_all=2.965

Partitioning of total diversity

Among aphids in a field

H _field /H _all

72.5%

Among fields in a farm

(H_farm–H_field)/H_all

13.5%

Among farms

(H_all–H_farm)/H_all

14.0%

Total

100.0%