Interspecific relationships between Rhopalosiphum rufiabdominalis and Sogatella furcifera mediated by rice secondary metabolites

Objective To explore the interaction mechanism between species of Sogatella furcifera (white-backed planthopper) and Rhopalosiphum rufiabdominalis (aphid), and the role of secondary metabolites in rice during the interaction between the two insects.

Method S. furcifera and R. rufiabdominalis were mixed in different proportions, and the total egg production and average daily spawning of white-backed planthopper adults were analyzed after pairing. The contents of oxalic acid, flavones and total phenols of each treated rice seedlings were determined, and the differences in compositions of secondary metabolites were analyzed by GC/MS instrument.

Result The total egg production of white-backed planthoppers treated with “15 aphids + 5 white-backed planthoppers” was only 131.67 grains, which was significantly different from that of “20 white-backed planthoppers” (214.60 grains), and the average daily fecundity was the same. The contents of rice flavones and total phenols treated with “15 aphids + 5 white-backed planthoppers” were 1.98 and 63.71 mg/L, respectively, which were significantly higher than those of other treatments. GC/MS analysis showed that the relative content of probucol in rice treated with “15 aphids + 5 white-backed planthoppers” was as high as 75.78%, while this phenolic substance was not present in the rest of the treatments.

Conclusion R. rufiabdominalis may inhibit the reproductive ability of S. furcifera through stimulating rice to promote the content of flavones and total phenols. The probucol may play a key role in the interaction between S. furcifera and R. rufiabdominalis.