Evaluation of petroleum spray oils for control of the Asian citrus psylla, Diaphorina citri (Kuwayama) (Hemiptera: Psyllidae), in China

The efficacy of petroleum spray oil against citrus psylla was tested in Guangzhou, China. As the oil concentration increased from 0.25% to 1.0% there was a linear decrease in the number of psylla of each stage present on foliar shoots after 8 days. When psylla infested shoots were sprayed with equivalent oil concentrations, survival was significantly different between oil treatments. Psylla survival was also stage-dependent, with Ist-end instars being the most susceptible and eggs being the most tolerant to oil. Oil efficacy was compared to an organophosphate pesticide and an insect growth regulator, and all provided similarly effective control of psylla nymphs. Control of eggs was not achieved by any of the treatments as application of sprays was not correctly timed.