Grape Phylloxera

(Viteus [Dactylosphaera] vitifolii; formerly Phylloxera vastatrix), an insect of the superfamily Aphidinea. The grape phylloxera, the most dangerous pest of the grapevine, is under foreign and domestic quarantine. A native of the USA, it was introduced into Russia on planting stock in the 1870’s. It is found in Moldavia, the southwestern Ukraine, the republics of Transcaucasia, and some regions of the Northern Caucasus.

The grape phylloxera has an oval, yellowish green body measuring 0.8–1.2 mm in length; it has red eyes and stinging-sucking mouthparts. Its full cycle of development takes place on the above-and below-ground parts of the grapevine. The root- and leaf- inhabiting forms do the most damage. Larvae of one or two instars winter on the roots and underground parts of the canes. After four molts a female is formed. She reproduces by parthenogenesis and lays as many as 200 eggs on the roots. The first-stage larvae that hatch attach themselves to the roots by suction and begin the next generation. During the growing season the root-inhabiting forms yield six to nine generations in southern regions, while fewer generations are produced by insects living farther north and deeper in the soil. In summer, nymphs appear among the root larvae. The nymphs turn into winged migrants that do not eat and whose only function is to lay eggs on the above-ground parts of the plants. Females hatch from the large eggs, and males from the small ones. The fertilized female lays a single egg that winters on a perennial shoot. In spring, leaf-inhabiting larvae hatch and cause the formation of galls on the new leaves of American grapes and hybrids. The larvae feed in the galls and after four molts are transformed into adult parthenogenic stem mothers, which lay up to 400 eggs. Beginning with the second or third generation both leaf-and root-inhabiting larvae are hatched in the galls. In autumn all individuals die, except the root-inhabiting larvae and winter eggs. The full cycle of development on the roots and leaves takes place only on some American grape species and hybrids. In Asian and European grape varieties, the root-inhabiting form is the only parasite and the only harmful pest.

The enzymes in phylloxera saliva cause damaged root tissue to thicken and form calluses and tumors; the surface of these formations cracks, bacteria and fungi penetrate the resultant ulcers, and the roots rot and die. The infected vines stop bearing fruit and usually die within five to ten years. American grapevines are subject to infection by leaf-inhabiting phylloxera but are not greatly damaged by the root-inhabiting form.

Control measures include the inspection of planting stock; the use of hexachlorane, methyl bromide, and other insecticides; the cultivation of vines grafted on resistant stock; the planting of highly resistant varieties and clones on sandy and sandy-loam soils; and periodic soil fumigation in contaminated areas.

REFERENCES

Prints, Ia. I. Vinogradnaia filloksera i mery bor’by s nei. Moscow, 1965.
Zashchita vinogradnikov ot filloksery. Moscow, 1971.
Peliakh, M. A. Spravochnik vinogradaria. Edited by A. M. Negrul’. Moscow, 1971.

I. A. KAZAS

grape phylloxera