TABLE 1.

Bacterial populations in 7-day-old pea aphids reared on chemically-defined diets of different total nitrogen concentrations^a

Clone and concentration of nitrogen in diet (mM)	Buchnera titer (no. of groEL gene copies per insect × 107)b	Serratia titer (no. of groEL gene copies per insect × 107)c	Contribution of Serratia to total bacterial load (% gene copies)	Buchnera density (no. of groEL gene copies per mg aphid wt × 107)d	Serratia density (no. of groEL gene copies per mg aphid wt × 107)e
IS
25	4.96 ± 0.228	0.22 ± 0.066	4.2	15.1 ± 0.70	0.7 ± 0.19
50	9.80 ± 0.732	0.39 ± 0.070	4.0	19.6 ± 1.47	0.8 ± 0.14
100	27.76 ± 2.482	0.30 ± 0.080	1.1	28.5 ± 2.85	0.3 ± 0.09
150	19.01 ± 1.948	0.26 ± 0.079	1.3	17.1 ± 1.76	0.2 ± 0.07
AISTIS
25	4.54 ± 0.371	0.44 ± 0.170	8.2	12.6 ± 1.03	1.2 ± 0.47
50	8.65 ± 0.794	0.79 ± 0.156	8.3	15.5 ± 1.42	1.4 ± 0.28
100	18.56 ± 1.608	0.21 ± 0.054	1.1	21.1 ± 1.83	0.2 ± 0.06
150	46.74 ± 3.592	0.70 ± 0.107	1.5	32.9 ± 2.53	0.5 ± 0.07

^aAll data, except nitrogen concentration and percent contribution, represent means ± standard errors (n = 5).

^bANOVA results: F_(1,32) for clone, 2.7 (P not significant); F_(3,32) for diet, 187.8 (P < 0.001); F_(3,32) for interaction, 20.8 (P < 0.001). (All ANOVA variables were ln transformed to obtain normality and homogenous variance prior to analysis.)

^cANOVA results: F_(1,32) for clone, 7.9 (0.01 > P > 0.001); F_(3,32) for diet, 4.2 (0.05 > P > 0.01); F_(3,32) for interaction, 2.5 (P not significant).

^dANOVA results: F_(1,32) for clone, 0.1 (P not significant); F_(3,32) for diet, 19.9 (P < 0.001); F_(3,32) for interaction, 14.3 (P < 0.001).

^eANOVA results: F_(1,32) for clone, 4.9 (0.05 > P > 0.01); F_(3,32) for diet, 11.4 (P < 0.001); F_(3,32) for interaction, 1.8 (P not significant).