Table 2.

Feeding bioassay (sachets) results with different bacteria against insecticide‐susceptible and insecticide‐resistant aphid clones.

Aphid	Bacteria	Bioassay location & physical conditions	P. fluorescens PpR24	P. fluorescens PfR37	Pantoea sp. PaR8	Enterobacter sp. CwR94	Enterobacter sp. ER93	Pa. agglomerans PaR38
4106A (SUS 1)	LC50 (Bacterial CFU ml−1)	Set I Aphid rearing room (University of Reading) at 21°C, 16‐h light/8‐h dark) regime	5.22 × 102	4.87 × 104	1.16 × 104	1.12 × 107	6.53 × 106	1.37 × 104
	95% confidence limits		3.5 × 102 – 7.55 × 102	3.13 × 104 – 7.45 × 104	3.22 × 103 – 3.68 × 104	9.57 × 106 – 1.34 × 107	5.44 × 106– 7.97 × 106	5.38 × 103 – 3.375 × 104
New green (RES 1)	LC50 (Bacterial CFU ml−1)		1.55 × 102	2.89 × 104	1.22 × 103	2.2 × 106	2.89 × 106	9.4 × 103
	95% confidence limits		7.7 × 101 – 2.62 × 102	2.31 × 104 – 3.62 × 104	1.32 × 102 – 5.1 × 103	1.59 × 106 – 3.13 × 106	2.12 × 106 – 4.07 × 106	6.19 × 103 – 1.43 × 104
	Tolerance Factor a		0.3	0.59	0.1	0.2	0.44	0.69
794J2 (RES 2)	LC50 (Bacterial CFU ml−1)		3.99 × 102	8.77 × 104	1.37 × 104	2.47 × 106	1.11 × 106	3.43 × 104
	95% confidence limits		2.38 × 103 – 5.23 × 103	1.63 × 104 – 4.98 × 104	2.47 × 103 – 1.59 × 104	1.97 × 104– 7.28 × 104	3.54 × 103– 2.44 × 104	3.17 × 103– 1.57 × 104
	Tolerance Factor a		0.77	1.8	1.18	0.22	0.17	2.51
4106A (SUS 1)	LC50 (Bacterial CFU ml−1)	Set II Specialist containment Insectary (Rothamsted research) at 21°C, 16‐h light/8‐h dark) regime	9.28 × 103	1.42 × 105	2.15 × 105	9.43 × 106	1.57 × 107	4.15 × 105
	95% confidence limits		6.34 × 103 – 1.36 × 104	9.81 × 104 – 2.06 × 105	1.34 × 105 – 3.45 × 105	7.19 × 106 – 1.32 × 107	1.04 × 107 – 2.79 × 107	2.67 × 105 – 6.6 × 105
5191A (RES 3)	LC50 (Bacterial CFU ml−1)		2.08 × 103	6.73 × 104	4.81 × 105	6.38 × 107	6.38 × 107	2.80 × 106
	95% confidence limits		1.09 × 103 – 3.85 × 103	3.60 × 104 – 1.27 × 105	2.82 × 105 – 8.63 × 105	3.40 × 107 – 1.62 × 108	3.40 × 107 – 1.62 × 108	1.20 × 106 – 8.76 × 106
	Tolerance Factor a		0.22	0.47	2.24	6.77	4.07	6.75
5444B (RES 4)	LC50 (Bacterial CFU ml−1)		4.95 × 104	6.51 × 105	1.07 × 105	4.17 × 107	8.65 × 107	4.42 × 106
	95% confidence limits		3.39 × 104 – 7.23 × 104	4.81 × 105 – 8.97 × 105	7.12 × 104 – 1.60 × 105	2.26 × 107 – 1.30 × 108	3.77 × 107 – 3.73 × 108	1.97 × 106 – 1.28 × 107
	Tolerance Factor a		5.33	4.58	0.5	4.42	5.51	10.64
4106A (SUS 1)	LC50 (Bacterial CFU ml−1)	Set III Controlled growth cabinet (University of Reading) at 21°C, 16‐h light/8‐h dark) regime	1.1 × 102	1.63 × 104	6.24 × 104	1.48 × 107	2.92 × 106	3.71 × 105
	95% confidence limits		5.8 × 101 – 1.92 × 102	1.08 × 104 – 2.45 × 104	2.72 × 104 – 1.47 × 105	9.27 × 106 – 2.77 × 107	1.88 × 106 – 4.91 × 106	2.04 × 105 – 7.14 × 105
4225B (SUS 2)	LC50 (Bacterial CFU ml−1)		3.3 × 102	6.53 × 104	3.53 × 104	1.10 × 107	9.04 × 106	2.19 × 104
	95% confidence limits		1.39 × 102 – 6.49 × 102	6.48 × 104 – 6.58 × 104	1.64 × 104 – 7.50 × 104	7.56 × 106 – 1.81 × 107	6.45 × 106 – 1.42 × 107	7.15 × 103 – 6.57 × 104
	Tolerance Factor a		0.64	1.34	3.02	0.98	1.38	1.6
Clone‐NS (SUS 3)	LC50 (Bacterial CFU ml−1)		6.9 × 101	3.13 × 104	1.79 × 104	3.49 × 104	2.47 × 106	6.68 × 104
	95% confidence limits		5.24 × 101 – 9.00 × 101	1.56 × 104 – 6.30 × 104	6.51 × 103 – 4.68 × 104	2.08 × 106 – 6.64 × 106	1.49 × 106 – 4.56 × 106	3.17 × 104 – 1.41 × 105
	Tolerance Factor a		0.63	1.92	0.29	0.24	0.85	0.18

To calculate LC₅₀ values of each bacterium for all aphid clones, 72 h aphid mortality readings at six bacterial concentrations ranging from 10⁷ to 10² CFU ml^‐1 were considered. The LC₅₀ dose of each bacterium for each aphid clone is shown along with lower and upper concentrations values at 95% confidence limits. The calculated Tolerance Factor for the four resistant and susceptible aphid clones is also shown. A reference 4106A (IS) aphid clone was used for calculating the resistance ratio at different physical laboratory conditions.

^a Tolerance Factor is a ratio of the LC₅₀ value of the tested resistant/susceptible clone to the LC₅₀ value of the laboratory susceptible clone.