Aphids are small sap-sucking insects and they are members of the superfamily called Aphidoidea. They have common names which are "greenfly and blackfly". Aphids in group are the fluffy white wooly aphids. Aphids are among the most destructive insects pests on cultivated plants in temperate regions. They are a highly successful group of organisms from an ecological standpoint because they have the ability to increase in numbers by asexual reproduction. They cannot be controlled easily because insecticides do not always produce dependable results,they feed on undersides of the leaves. Some use water jets and soap sprays to destroy them and they are so effective on them.
Aphids have enemies and they are Ladybugs, hoverfly larvae,parasitic wasps, aphid midge larvae,crab spiders, lacewing larvae and entomopathogenic fungi.
They are more or less seen in the tropics than in the temperate zones. They can move to places very far,mainly through passive dispersal of winds. They are distributed nationwide but are common in temperate zones.
Aphids are monophagous that is,they feed only on one plant species, some aphids like the green peach aphids feeds on hundreds of plant species across many families. They have two little tubes at the end of the abdomen called cornices, their eyes are small and with sucking mouthparts. Their colors are green but may be red,black or brown. They move slowly and doesn't jump or hop and they have daily long antenna.
They can be found near their food plants and sometimes hide in the curls of leaves. Where there is plant,aphids are there too. They suck plant juices out of the leaves, stems or roots of plants. The juices contains much sugar than protein. The sugary fluid they excrete is called "honeydew" and many other insects feed on it.
Aphids are mostly under 1/4 inches (6mm) long. Some aphids doesn't have wings while others have two pairs of transparent or colored wings, the front pair than the hind pair.
The damage done to plants by aphids is due to numbers of causes which are;
- Loss of sap
- Clogging of leaf surfaces with honeydew
- Growth of molds and fungi on the honeydew
A common symptoms of aphid infestation is leaf curl,it occurs when a colony attacks the underside of a leaf,causing its desiccation. Only the downward curl provides protection for the colony while the leaf become useless to the plant. There are some aphids that cause damage to food crops and they are;
- Grain cabbage
- Cornroot
- Apple
- Wooly apple
- Hickory aphids
Despite that aphids destroys plants,they are considered as fascinating creatures. Their tendency to hang out together makes it easy for them to spot. They have relationship with ants and both protect each other from other insects.
TYPES OF APHIDS
1 Schizaphis Graminum: They are called green bug and the most widespread aphids and one of the most destructive. They feed mostly on wheat,oats and grain. They reproduce without mating in warmer climates.
2 Aphis Gossypii: These are called melon aphid,they feed on melons. They have the ability to live off a wide range of plants and it makes them to be well known and popular. One of its characteristics is that it thrives in warm temperature and avoids cold
3 Black bean aphid: These are small black insect and have a broad,soft body. Their other names are blackfly,bean aphid and beat leaf aphid. They act as vector for viruses that cause plant disease and the honeydew.
How to get rid of Aphids
Sprinkle cold water on the leaves,this will make it difficult for aphids to find their way to the plant because they need a cool place but when it is wet,they can't go near it.
If the aphids have invaded the leaves,dust it with flour. It constipates the pests
Apply Neem oil, insecticidal soaps and horticultural oils because they are effective against aphids
Soapy water should be applied in the leaves every 2-3 days for two weeks
WAYS YOU CAN CONTROL APHIDS
1 Clean away aphids- Use your hands or soft toothbrush to remove aphids from plants.
2 Aphid wasps: This is a biological control by introducing aphid wasps into the garden. These wasps will target aphids and kill them no matter how they come in groups.
3 Syrphid flies: This is not easy to find but they flourish in most flowering garden. Apply them and keep them by maintaining a pesticide free garden
4 Ants: Since we know ants and aphids are related,while aphids provide food to them,ants offer protection. One way to make aphids more harm to any treatment is to remove the ant away from the plant. Pour a jar of honey near the plant and this will allow you clean the plant without hurting yourself.
5 Garlic: Garlic has a pungent odor and it has been found as effective against aphids. Put garlic on the plants,they will move away.
If Aphids are not controlled early before they cause damage to plants,they can cause considerable economic damage to other crops.