Table 3.

LC₅₀s for S. exigua second instars treated with (i) SeUS2-A OBs or SeUS2-WT OBs, (ii) mixtures of SeUS2-A OBs and SeUS2-C OBs, and (iii) OBs comprising co-occluded mixtures of SeUS2-A and SeUS2-C

Virus	LC50 (OBs/ml)
	Mean	Relative potencya	95% confidence limitsb
			Lower	Upper
(i) SeUS2-A	1.31 × 104	1	–	–
SeUS2-WT	1.69 × 104	0.77	0.23	1.30
(ii) Mixtures of OBs
9A + 1C	1.54 × 104	0.84	0.56	1.22
3A + 1C	2.00 × 104	0.65	0.43	0.98
1A + 1C	2.85 × 104	0.46	0.30	0.69
1A + 3C	5.80 × 104	0.22	0.13	0.37
1A + 9C	1.97 × 105	0.06	0.02	0.15
(iii) Co-occluded genotypesc
9A + 1C	1.60 × 104	0.81	0.52	1.26
3A + 1C	1.50 × 104	0.86	0.57	1.29
1A + 1C	9.30 × 104	0.14	0.08	0.23

^aRegressions could not be fitted with a common slope; a test for nonparallelism was significant (χ² = 40.71, df = 9, P < 0.001). Relative potency was therefore calculated as the ratio of LC₅₀ values of each inoculum and SeUS2-A. As such, the relative potencies indicate the relative pathogenicity of each inoculum compared with that of SeUS2-A.

^bThe confidence limits refer to relative potency values.

^cCo-occluded mixtures of 1A + 3C and 1A + 9C OBs could not be produced, as the proportion of SeUS2-C was markedly lower than that of the ODV inoculum used to inject larvae.