Blooming Times – Friend Or Foe
by Flo Whitaker
Defeat pesky pests in your garden this summer by harnessing the power of natural predators.
‘The World of Aphids’ is a depressing topic for a gardening article. For a start, there are so many different aphid species; approximately 500 in the UK alone. Colonies range in size from a few dozen individuals to tens of thousands. They feed by sucking the sugary, nutritious sap from leaves and stems. Some are fussy eaters, requiring a specific type of plant but most aphids are less picky and will nosh up anything within reach. Once attacked, a plant has to spend valuable resources replacing the sap and quickly healing over the wounds. Aphids excrete ‘honeydew’ as they feed; in effect, aphid faeces – yuck! Mould spores wafting around in the air are attracted to the honeydew, making ideal conditions for a secondary infection to set in. Aphids are usually wingless, but if a colony becomes too large for the host plant to support, they can spontaneously grow wings and fly off to find another food source. And just when you thought things couldn’t get any worse – guess what? Many aphid species are born ‘pregnant’ with the next generation ready to go.
The term ‘aphid’ includes what we commonly refer to as greenfly, whitefly and blackfly, (tiny black insects found inside flowers are not blackfly – they are harmless pollen beetles). Aphids usually congregate on young growth where the plant tissue is soft. How to control them? In the first instance, I would recommend waiting for 24 hours in case natural predators move in. If they fail to materialise or the plant is severely infested, then act quickly. Removing aphids by hand is tedious, but instantly effective. Their soft bodies make them vulnerable to squashing. If this does not appeal (!) then a powerful jet of water from a hose will quickly knock them off. Old-fashioned chemical controls tended to kill everything in sight. Modern sprays are designed to be more specific, but great care should be taken. Spray early in the morning, or at dusk when the likelihood of harming bees and other pollinators is reduced. Always follow the instructions and never spray in windy conditions. A drift of spray could be harmful to other plants – and you.
Encourage natural predators in your garden, they will provide the best pest control. Ladybirds have voracious appetites, as do their immature larvae. These scary-looking mini beasts are greyish-black, sometimes with orange/yellow markings and spines. Looking nothing like an adult ladybird; they are often mistakenly thought to be ‘nasty pests’ and destroyed. Garden birds with hungry youngsters to feed will take 1,000’s of aphids every day. Parasitic wasps hunt aphids. Lacewing and hoverfly larvae gorge on them, as do those fearsome predators, earwigs. Have pity – it’s not fun being an aphid. Everything wants to eat you.