3 RESULTS
3.1 Pre-infestation of rice by BPH female adults reduced subsequent BPH attack
We performed choice and no-choice tests to investigate whether pre-infestation of rice plants by BPH gravid female adults influenced subsequent BPH infestations. In the choice test, BPH nymphs and female adults preferred un-infested rice plants to pre-infested ones (Figure 1a, b). In the no-choice test, the survival rate of nymphs was relatively lower on pre-infested rice than on un-infested rice (Figure 1c). The amount of honeydew excreted by BPH in pre-infested rice was significantly lower than that in control rice (Figure 1d). Pre-infestation by BPH gravid females therefore increased rice resistance to BPH.