Damage, nuisance

The different species of cochineals encountered on vines are all polyphagous species and, for some, serious pests on crops other than the vine. Stinging and sucking insects, mealybugs by inserting their mouthparts into the tissues of the host cause lesions and the prolonged uptake of the sap can induce a weakening of the plant in case of high density. Coccidae and Pseudococcidae feed in the phloem, while Diaspididae bite the cortical parenchyma.

Mealybugs that bite into the phloem excrete a sweet honeydew that attracts ants that protect these pests for this purpose. In addition, this honeydew promotes the development of sooty mold, a fungus with black mycelium, which by developing on the surface of leaves and berries, harms the quality of the harvest. Ants, on the other hand, can participate in the spread of mealybugs by transporting the larvae. The presence of ants on the vines is a good indication of infestation by mealybugs.

The most serious is the potential transmission of viruses by bites of certain species such as Parthenolecanium corni, Pulvinaria vitis , Heliococcus bohemicus and Phenacoccus aceris , the viral particles being inoculated by these insects. The most damaging to grapevine are , leaf roll viruses Grapevine leafroll-associated virus (GLRaV) (Figures 1 and 2).