TABLE 3.

Effect of host plant and aphid genotype on Buchnera titers^a

Source of variation	df	Mean square	F	P
Host plant	2	691.37	22.81	<0.0001
Aphid genotype	3	64.73	2.14	0.1127
Host plant × aphid genotype	6	433.66	14.31	<0.0001

^aDetermined by two-way ANOVA.