There are over 500 – yes 500! – aphid species. On the up side, many of these sap-sucking pests will only infest one or two types of plants, so the insects you spot on one crop aren’t likely to attack another. Companion planting can discourage them and there’s an easy, organic way to get rid of small numbers. Either knock them off your plant with a jet of water or squash them between your fingers.
If you’re struggling to identify aphids, don’t worry – you’re not alone. The pests are called greenfly or blackfly for good reason – species come in range of colors including brown, white and yellow. They vary in size, too, ranging from a hard to- see 1mm to a whopping 7mm long. A few, including the woolly aphids you spot on apple stems, even cover themselves with a fluffy secretion which looks a bit like mold. Still, they cause similar symptoms – stunted growth, weakened plants and distorted foliage. Check buds, shoot tips and the lower side of leaves as these are the most common sites of infestations.
Lovely name aside, honeydew isn’t something you want to find on your crops. It’s the sticky deposit left by aphids while they suck the sap from plants. It can grow sooty mold and also attracts ants. In fact, the latter love the sugary substance so much they’re known to ‘farm’ the pests and protect them from predators. Luckily other, more helpful, insects will eat your aphid population. Many gardening companies sell ladybirds, lacewing larvae and several parasitic wasps that can be used as biological controls.
Are your plants in danger from aphid transmitted viruses? Tomatoes, strawberries and raspberries are just a few of the at-risk crops. Keeping fruit and veg under cover or protected by a fine mesh can cut the likelihood of infestations. Alternatively, pyrethrum- or fatty acid-based sprays such as Py Garden Insect Killer or Doff Greenfly and Blackfly Killer provide a level of control. Non-organic gardeners might also choose to try synthetic pesticides. Check the manufacturer’s instructions – these won’t be suitable for all edible crops and shouldn’t be used when they’re likely to harm beneficial pollinators.
After spending the warmer months on your fruit and veg, aphids return to a tree or shrub to lay overwintering eggs. If you believe that eggs may be hiding on fruit trees and bushes, there’s an easy solution. Use a plant oil-based wash, like Vitax Winter Tree Wash, during colder weather while your plants are dormant. These products are designed to get rid of any pests lurking in nooks and crannies.