Grapevine Leaf Phylloxera

Grapevine leaf phylloxera (Daktulosphaira vitifoliae) is one of the most dangerous and insidious pests of grapevines, capable of causing devastating damage to vineyards. This small, yellowish-green aphid feeds on plant sap and exists in two forms: root (radicicola) and leaf (gallicola).

The leaf form most frequently attacks American rootstock varieties and hybrid grape forms. Its danger lies in its phenomenal rate of reproduction—the pest is capable of producing up to 7–8 generations in a single season, rapidly turning into an epidemic across the entire vineyard if timely measures are not taken.

Damage and Infection Mechanism

The damage caused by this pest is highly specific and easily visible. While feeding, phylloxera secretes enzymes that stimulate plant leaf tissue proliferation. As a result, characteristic wart-like galls form on the underside of young leaves, inside of which females lay hundreds of eggs.

In cases of severe infestation, galls completely cover the leaf blade, leading to deformation, critical disruption of photosynthesis, and premature drying. The vine suffers from nutrient deficiency, ripens very poorly, yields drop sharply, and the bush loses its winter hardiness.

Under severe vine infestation, yield losses can reach up to 60%.

Phylloxera Control Methods

Controlling leaf phylloxera is complicated by the fact that larvae and females are securely hidden inside the galls, making them difficult to reach with standard contact products.

If the infestation is minor or localized, it is recommended to remove infected shoots and leaves prior to spraying, followed by an insecticide treatment.

Effective control requires translaminar insecticides, such as Emax Pro. The optimal timing for treatment is the emergence of first-generation crawler larvae (typically coinciding with bud break and the appearance of the first 2–3 leaves) or immediately upon detecting the first isolated galls. Spraying must be performed thoroughly, ensuring abundant coverage on both the upper and lower surfaces of the leaves, paying special attention to dense foliage or overlapping shoots.

The efficacy of Emax Pro is powered by its key active ingredient—emamectin. Due to its pronounced translaminar activity, emamectin rapidly penetrates through the cuticle into plant tissue, forming toxic reservoirs for the pest and reaching phylloxera even inside the galls. Once inside the insect's system, emamectin targets its central nervous system by irreversibly stimulating the release of gamma-aminobutyric acid (GABA), leading to rapid muscle relaxation and total paralysis. Within a few hours of contact or ingesting treated tissue, the phylloxera completely stops feeding and subsequently dies, providing reliable, long-lasting protection for the vineyard.

Additionally, Emax Pro exhibits ovicidal activity, destroying egg clutches inside the galls. Because direct control results are difficult to spot with the naked eye, focus should be placed on stopping the growth and spread of new galls.

Application rate: 10 g / 10 L of water. It is strongly recommended to add the Izomax  adjuvant (3 mL / 10 L) to the tank mix to accelerate and enhance penetration into the plant while ensuring uniform coverage over infected leaves.

To view the performance results of Emax Pro + Isomax, check the report: VIEW