''Euceraphis betulae'', the birch aphid or silver birch aphid, is a species of aphid in the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Hemiptera Hemiptera (; ) is an order (biology), order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, Reduviidae, assassin bugs, Cimex, bed bugs, and shield bugs. ...

. It is a tiny green insect with a soft body and wings. It is found living on the European silver birch tree ('' Betula pendula'') where it feeds and multiplies on the buds and leaves by sucking sap.

Description

The silver birch aphid is a light green colour with a bluish tinge. The blueness is due to the dusting of blue wax particles which are particularly obvious on the antennae and legs. All adults have membranous wings and during the spring and summer, all individuals are female. The mouthparts are specialised to form a slender stylet for piercing and sucking sap from their

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

tree.

Biology

Eggs that have overwintered on birch twigs hatch out in the spring. The nymphs feed on the leaf buds as they burst and on tender young leaves. They grow rapidly into winged females that, as soon as they are adults, start to reproduce by parthenogenesis, producing live young. This new generation develops into further winged females and the numbers of aphids soon builds up. They take to the wing rapidly if disturbed. Some fly to nearby silver birches and others to other parts of the same tree but by about July they stop reproducing. In September the birch leaves begin to turn yellow and the aphids resume reproduction and further nymphs are born

viviparously Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the ...

. As the days shorten, there is a change in the reproductive pattern. The next generation of adults produced consists of greyish, winged males and brown, winged egg-laying females. After mating, the females lay batches of orange eggs on birch twigs. The adults die off and the eggs soon turn to a glossy black colour. They are able to withstand harsh winter weather and hatch in the spring when the tree is about to resume growth.

Ecology

Like many other species of aphid, ''Euceraphis betulae'' is very specific as to the identity of its host. The silver birch is an ornamental tree native to Europe which has been introduced into North America, Australia, New Zealand and other parts of the world and the aphid has travelled with it. The aphid has not adapted to colonise other species of birch native to these countries. In Europe, the closely related '' downy birch'' (''Betula pubescens'') has its own species of aphid, '' Euceraphis punctipennis''. At one time this was thought to be identical to ''Euceraphis betulae'' but there have been found to be

chromosomal A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

differences between the two, and they are now considered to be separate species. Ladybirds and their larvae feed on aphids. In America the eyed ladybird (''

Anatis ocellata ''Anatis ocellata'', commonly known as the eyed ladybug, is a species of ladybug in the family Coccinellidae. It has black spots on a red background, with each spot surrounded by a yellowish halo. In one color variation, a specimen found in Scot ...

'') specialises on the aphids colonising various trees. Their diets include the silver birch aphid and pine aphids. The cream-spot ladybird (''

Calvia quatuordecimguttata ''Calvia quatuordecimguttata'', the cream-spot ladybird, is a species of ladybird in the family Coccinellidae. Its distribution is holarctic, it being found in Europe and through the East Palearctic to Japan. It is introduced to North America. ...

'') also feeds on ''Euceraphis betulae''.

References

{{Taxonbar, from=Q5405776 Aphididae Insects described in 1855 Hemiptera of Europe