Aphid

Aphids are small <a href="/facts/Sap/cxdgQYP8">sap</a>-sucking <a href="/facts/Insect/IgDNvnUL">insects</a> in the <a href="/facts/Taxonomic_rank/bPFQpe9A">family</a> Aphididae. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white <a href="/facts/Eriosomatinae/MgrmRs1r">woolly aphids</a>. A typical life cycle involves flightless females giving <a href="/facts/Viviparity/EEMn4rVx">live birth</a> to female <a href="/facts/Nymph_(biology)/3LjQyPSG">nymphs</a>—who may also be already <a href="/facts/Pregnancy/vEKYGpep">pregnant</a>, an adaptation scientists call <a href="/facts/Telescoping_generations/UMHvQQxU">telescoping generations</a>—without the involvement of males. <a href="/facts/Developmental_biology/9dLJhCCv">Maturing</a> rapidly, females breed profusely so that the number of these insects multiplies quickly. <a href="/facts/Alate/Dbw19pPv">Winged females</a> may develop later in the season, allowing the insects to colonize new plants. In <a href="/facts/Temperate_climate/6WPypCzC">temperate</a> regions, a phase of <a href="/facts/Sexual_reproduction/hmsXy53s">sexual reproduction</a> occurs in the <a href="/facts/Autumn/Rk9KKsS2">autumn</a>, with the insects often overwintering as <a href="/facts/Egg/2a1McdtR">eggs</a>.
The life cycle of some species involves an alternation between two species of host plants, for example between an annual crop and a <a href="/facts/Woody_plant/xXCI9yys">woody plant</a>. Some species feed on only one type of plant, while others are generalists, colonizing many plant groups. About 5,000 species of aphid have been described, all included in the family <a href="/facts/Aphididae/E4Yyzfug">Aphididae</a>. Around 400 of these are found on <a href="/facts/Crop/JoQKR5R8">food</a> and <a href="/facts/Fiber_crop/ucL2g6AX">fiber crops</a>, and many are serious pests of <a href="/facts/Agriculture/TGztqzJs">agriculture</a> and <a href="/facts/Forestry/puvod5MV">forestry</a>, as well as an annoyance for <a href="/facts/Gardener/vj2nF0mB">gardeners</a>. So-called dairying <a href="/facts/Ant/Gml7kzWT">ants</a> have a <a href="/facts/Mutualism_(biology)/29hCDDS2">mutualistic</a> relationship with aphids, tending them for their <a href="/facts/Honeydew_(secretion)/oKGpBzTS">honeydew</a> and protecting them from <a href="/facts/Predator/JEGdrX3f">predators</a>.
Aphids are among the most destructive insect pests on cultivated plants in temperate regions. In addition to weakening the plant by sucking sap, they act as <a href="/facts/Vector_(epidemiology)/bepASE2M">vectors</a> for <a href="/facts/Plant_virus/gTtPbVCB">plant viruses</a> and disfigure ornamental plants with deposits of honeydew and the subsequent growth of <a href="/facts/Sooty_mould/Fjz0X3gs">sooty moulds</a>. Because of their ability to rapidly increase in numbers by <a href="/facts/Asexual_reproduction/HpovW0VS">asexual reproduction</a> and telescopic development, they are a highly successful group of organisms from an ecological standpoint.
Large-scale control of aphids is not easy. <a href="/facts/Insecticide/1xYL3MSD">Insecticides</a> do not always produce reliable results, because of <a href="/facts/Pesticide_resistance/FvetsYFQ">resistance</a> to several classes of insecticide, and because aphids often feed on the undersides of leaves, and are thus shielded. On a small scale, water jets and soap sprays are quite effective. Natural enemies include predatory <a href="/facts/Coccinellidae/G178JasK">ladybugs</a>, <a href="/facts/Hoverfly/8ShGezPP">hoverfly</a> larvae, <a href="/facts/Parasitic_wasp/vLVmVHBs">parasitic wasps</a>, <a href="/facts/Aphidoletes_aphidimyza/11zloDHv">aphid midge larvae</a>, <a href="/facts/Crab_spider/Krp6N4sp">crab spiders</a>, <a href="/facts/Lacewing/YEHN5JEw">lacewing</a> larvae, and <a href="/facts/Entomopathogenic_fungus/mbhwcV9S">entomopathogenic fungi</a>. An <a href="/facts/Integrated_pest_management/XWCwBShW">integrated pest management</a> strategy using <a href="/facts/Biological_pest_control/khkjgaQw">biological pest control</a> can work, but is difficult to achieve except in enclosed environments such as <a href="/facts/Greenhouse/VBHMUgfM">greenhouses</a>.

Aphid open-in-new

Aphid