In praise of greenfly

God may have a special preference for beetles but, frankly, aphids (greenfly to you, squire) are more my thing. If that seems a barmy thing for a gardener to say, rest assured I get just as irritated as everyone else by their vigour-sapping, leaf-curling, virus-transmitting presence on my flowers, fruit, vegetables and greenhouse plants. When they stick their hollow feeding tubes (stylets) into soft stems, the pressure in the plant pumps sugary sap into their bodies and they then excrete it, dripping sticky honeydew on to leaves below; this attracts small fungi called sooty moulds. What could be more annoying than that? But I also understand that, as the plant ecologist Ken Thompson puts it, they are the garden equivalent of krill: ‘small, extremely abundant and the basis of a whole ecosystem of predators and parasitoids’. In other words, our gardens would be very different, and poorer, without them.