Aphids, Aphid, Plant Aphids, Greenfly, Blackfly
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Deal with aphids organically: Method 4
Deal with aphids organically: Method 3
Deal with aphids organically: Method 2
Aphids are one of the most common garden pests. They're small, sap-sucking insects in the superfamily Aphidoidea. There are over 4000 species worldwide, and in low to moderate numbers, they're not too harmful to garden plants. Aphids feed on the cell contents of plant leaves, which over time reduces the green leaf area available for photosynthesis. They're often seen feeding in clusters on new plant growth. However, a general decline in plant vigour will be noticed with a substantial infestation. Other common symptoms include leaf yellowing and abnormal growth. Ants can form mutually beneficial relationships with aphids, which can sometimes make infestations worse. They'll protect Aphids from predators in return for honeydew secretions.
Aphids produce large amounts of honeydew, which may attract ants or black sooty mould.
Aphids are food for other insects and garden animals.
Adults: Aphids may be green, brown, yellow, black or red depending on species and their food source. They are rather small and have soft, pear-shaped bodies. Some may have a waxy or woolly coating and are known collectively as as 'Woolly aphids'. Aphids possess complex life cycles, spending prolonged periods on different plants depending on the time of year. During these times, a female can produce winged, or wingless offspring. For this reason, some aphids won't have wings. Nymphs: Very similar to adults but the wings will be absent, and sometimes they will appear paler in colour. They are much smaller so they can be challenging to detect at this stage. Eggs: The eggs look like tiny white dots, generally associated with the main colony beneath the leaves of the host plant.
Colonies of aphids clustered on young stems, leaves and buds. Yellow leaves. Leaf and stem distortion. A sticky substance on the plant or leaves, known as honeydew. Honeydew can attract ant colonies, and black sooty mould. Premature leaf fall. Plants generally looking 'unhappy'.
General good housekeeping can help prevent infestations. Before planting, be mindful of the space you leave between crops and shrubs. Weeds and plant debris can facilitate a bad pest infestation. Companion planting with strong-smelling herbs such as Basil, Chive, Allium and mint are believed to deter aphid activity. Nasturtium is a brilliant buffer plant which can attract insects away from vegetables and fruits. Aphids aggregate in areas of new growth, so be sure to check in all the nooks of plants, especially under leaves! For heavier infestations, treat plants with a strong jet of water to dislodge the insects from the plant. Alternatively, use a light, soapy mixture sprayed on the plant or even just squashing them. A mixture of tomato leaf and distilled water is believed to deter aphids. Once the leaves are drained, dilute the remaining mix with 1-2 cups of water. Tomato plants contain the same allergens as nightshade. It's not advised to use this method if allergic to nightshade. Garlic or chilli-based sprays diluted with water can act as a natural insect repellent. Placing ant traps near infested plants will help to control secondary ant infestations. Aphids possess an array of natural enemies (ladybirds, wasps and lacewings, to name a few!). Attract beneficial insects by planting a selection of indigenous plants, incorporating an insect hotel, or by letting some bits of the garden grow wild.
Wherever possible, aphids should be tolerated on plants because they are food for other wildlife. Aphid populations tend to peak during spring, but die off when natural enemies become more apparent later in the summer. When using chemicals, it’s always best to act when nymphs (immature aphids) are most active, which tends to be in the spring. Assess the plants' size. Full pesticide coverage for trees and large shrubs is expensive, if not impossible, to achieve. Likewise, apply pesticides before flowering occurs. Sprays can be indiscriminate killers, removing useful insects as well as the bad. Killing the beneficial insects can make pest problems worse in the following year. Contact insecticides containing natural plant oils can be more environmentally benign than synthetic pesticides. Look out for products containing natural pyrethrums, fatty acids and plant oils. Any product containing oil should be applied during colder periods of the day. Synthetic pyrethroids that are available for home use include ingredients: deltamethrin, lambda-cyhalothrin and cypermethrin. These can be applied less frequently. Likewise, if you intend to eat your crop, be sure it is listed on the bottle and always follow directions carefully.