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|The aphid (or plant lice) is a sucking insect and belongs to the group of the lice (sternorrhyncha). The traces of this notably successful group date more than 280 million years back. About 800 different species of aphids are native to Central-Europe - worldwide a few thousand species are known. |
Depending on the weather aphids proliferate explosively and live in a big number on sprouts, burgeons, or under the leaves of nearly all useful and ornamental plants. With their proboscis they can reach in-between the cells to the nutriment veins of the plants, from which they can get the sap. Leaves, attacked by lice, crimp or coil up, while the sprouts dwarf. In addition many species can transfer deadly diseases. Because of this they are often hold for major varmints in the yard and the farming industry.
|Since aphids nourish on saps, rich on carbohydrates, but need a bigger part of proteins than offered, they typically excrete a large amount of a sugary dilution (honeydew), which often attracts numerous other insects and vertebrates. |
Some species of the aphids even have a symbiosis with ants, which nourish on the delicious honeydew and in return take care of, protect and support the spreading of the aphid-colony.
|The seven-point ladybug, the hoverfly, and the common green lacewing belong to the major natural enemies. Ladybugs and their grubs are very effective aphid-eaters. Every bug devours in his live as a grub and his adultery several thousand aphids - a proud number. But also uncountable grubs of other insects, spiders, and even birds feed on the aphids.|
|Aphids belong orderly to the clade of the arthropod (arthropods), the class of the insects, the subsection of the pyterigotes (pterygota), the rank of the bug (hemiptera), the subordination of the homopteras (homoptera), and the taxon of the lice. Within the same breed there are several different forms of appearances, because of which animals of succeeding generations can differ in their looking and their biology.|
| The animals are between one and seven millimetres long and normally flat to oval shaped. Every species has a pungent and sucking tool, six legs, a pair of antenna and two tubelike protuberances (siphone) at their back, at which they excrete the sugary honeydew. A larger part of the species can build wings, which can be missing as well, depending on the generation of the species. The bodies are mostly green, but can be yellow, brown, and even red or black coloured, too. |
|The antennas often exist of different forms or lengths, but are most times long with a maximum of six segments. They are composed of two short and thick limbs and one to four hairline limbs. The legs are long and thin, and there are no cannon bones, like related species have. They have pads existing of mostly two limbs with two claws.|
|Similar to the bedbug the aphids are characterised by their pungent and sucking tool, with which they tap the plants in order to nourish of the plant sap. The sucker exists of a number of stab-bristle, which are built of the transformed mandible and the first maxilla. These stab-bristles are in a channelling, which is build of the labium.|
|Most aphids don't produce wings, but because of the lack of food or a change of generation, the offspring can build individual wings, which can ease their movement to other plants. |
If wings exist, it is a pair of two skinny wings with indirect muscles for flying. The venation is differently reduced. The animals can fly for shorter distances, but their flight is not very skilful.
|Aphids are heterogeneous, which is a change between sexual and agamous propagation. At the beginning of a population in the spring there are normally only agamous animals. The agamous propagation has the advantage that the population size can increase fast. This way each day 5 living clones, which are genetic identical, are created. (picture on the right) |
Especially warm and dry weather in the spring encourages female aphids to increase their population explosively. The life expectancy of aphids is just a few weeks.
|Depending on the clime or the alternation of generations sexual animals emerge in the autumn, whose females deposit eggs, which are the hibernation in Central-Europe. This way only little offspring is generated. By altering the generations sometimes a population with wings is generated, which can overcome long distances to new hosts.|
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