[Objectives]  To reduce the use of imidacloprid by developing a bactericide that targets yeast-like symbiontes (YLS) in Nilaparvata lugens and is compatible with imidacloprid. [Methods]  An antagonistic actinomycete was isolated from a soil sample using Pichia guilliermondii as the indicator strain and its active ingredient purified and analyzed. The effectiveness of the active ingredient for controlling N. lugens, both alone, and in combination with imidacloprid, was determined. [Results]  The actinomycete, named Streptomyces albus 2013, displayed a high level of antagonistic activity against P. guilliermondii. The major bioactive ingredient of S. albus 2013 was identified as tetramycin A. Treating rice seedlings with 500 mg/L or 750 mg/L tetramycin A significantly reduced the number of P. guilliermondii in N. lugens feeding on these plants to 3.1 copies/L and 1.2 copies/L, respectively, compared to the control group which had 4.5 copies/L. The mortality rates of N. lugens treated with a mixture of 500 mg/L imidacloprid and 750 mg/L tetramycin A (1︰1, v/v), were 50.3% and 59.4% higher than that of those treated with the same concentration of imidacloprid alone. [Conclusion] A combination of imidacloprid and tetramycin A isolated from a strain of S. albus 2013 not only increased mortality of N. lugens but also reduced imidacloprid usage. These findings provide a novel strategy for controlling N. lugens.