Figure 2. Mean proportion of infective and noninfective aphids responding in a dual-choice bioassay examining host plant selection preferences to BYDV-infected and sham-inoculated wheat (noninfected plants previously fed upon by noninfective aphids) as influenced by indirect effects of feeding on virus-infected plants.

Each replicate (n = 12) consisted of one arena with noninfective aphids paired with one arena of infective aphids, randomized in a complete block design over time. Statistical analyses compared the response of infective and noninfective aphids to the BYDV-infected or sham-inoculated plant treatment. (a) Aphid responses at the first observation point made 12 h after release. Noninfective aphids preferred BYDV-infected wheat compared to infective aphids (generalized linear model; χ² = 3.12, p = 0.0774, marginally significant). Infective aphids preferred sham-inoculated plants compared to noninfective aphids (generalized linear model; χ² = 3.12, p = 0.0774, marginally significant). (b) Aphid responses pooled over time (6 observations). Noninfective aphids significantly preferred BYDV-infected wheat compared to infective aphids (generalized linear model; χ² = 19.33, p < 0.0001). Infective aphids significantly preferred sham-inoculated plants compared to noninfective aphids (generalized linear model; χ² = 20.14, p < 0.0001). Data are means ± SE following logit transformation. Errors bars are s.e.m.