Woolly Apple Aphid

Woolly Apple Aphid 

(Eriosoma Ianigerum), an insect of the family Aphididae, extremely injurious to apple trees.

The woolly apple aphid made its way to Europe from the USA. It is found in North and South America, southern Africa, Europe, and the islands of New Zealand and Tasmania. It is found in the southern USSR. The European woolly apple aphid reproduces without fertilization and in one summer may produce as many as 19 generations. It hibernates on the trunks and roots of apple trees.

Colonies of woolly apple aphids, secreting waxy white threads, cover shoots, trunks, and roots of the trees like snowflakes. Feeding on tree sap, the woolly apple aphid causes the formation of excrescences and fissures, resulting in the decreased productivity and impaired growth of the tree. It occasionally attacks the pear tree, but causes only slight harm. Seedlings are especially susceptible to the woolly apple aphid. Control measures include strict quarantine; disinfestation of seedlings; release of the ichneumon fly, Aphelinus, in orchards; spraying the trees with insecticides; cutting away of branches of nearby trees which obstruct the top of the tree; and removal of root suckers.

REFERENCES

Vereshchagina, V. V. Krovianaia tlia i bor’ba s nei. Kishinev, 1958. Shchegolev, V. N. Entomologiia. Moscow, 1964.

D. A. KOLESOVA