Research into biological control of aphids continues. However, because of the high growth rates of aphid populations, it is unlikely that they can be fully controlled in all cases. Correct cultural practices (e.g. avoiding nitrogen overfertilization) may reduce the rate of increase of aphid populations and enhance the effectiveness of biological control. Spot treatments with chemicals are still helpful to prevent local outbreaks. The introduction of easy-to-use systemic aphicides implies a serious challenge to biological control. Fortunately, the demand for biological control is still high, both from growers and consumers, and even stronger demand may be expected as resistance to aphicides becomes more common among local aphid populations.