| Abstract: | Abstract In order to understand the differentiation of amino acid requirments in host‐related populations of the brown planthopper (BPH), Nilaparvata lugens (Stål), we established three BPH populations by separately maintaining them on three rice varieties, i.e. TN1 (common susceptible control), Mudgo (containing resistant gene Bph 1) and ASD7 (containing resistant gene bph2) for over 30 generations, and then reared them on 20 holidic diets, each with distinct overall amino acids and ratio of essential amino acid (EAA) to nonessential amino acid (NEAA). The emergence rate, brachypter rate, nymphal duration and weight of newly molted adults were evaluated and compared. The results showed significant difference among the three populations in the effect of amino acid variation on BPH performance, ascending in an order of Mudgo population ASD7 population > TN1 pupulation. The results also indicated that the required optimum concentrations of overall amino acids by BPH populations on Mudgo and ASD7 were 4.0% ‐4.8% and 4.0%, respectively, higher than that of TN1 population (2.4% ‐ 3.2%). In addition, it was found that Mudgo and ASD7 populations were more sensitive to the concentration of EAAs than TN1 population. We propose that there is substantial differentiation in responses to dietary amino acid conditions among different host‐associated BPH populations and that such differentiation may be closely related to the induced virulence shift on resistant rice varieties. |
