The scientific name is Empoasca decedens, vulgarly known as the green cicada.
The cicada has always been widespread in the Mediterranean basin, but since the 1990s it has begun to be a serious problem for farmers. Widespread mainly in the south, it also sees a fair presence in northern regions such as Emilia Romagna, Veneto, Tuscany and Liguria.
General damage: it is a polyphagous species that attacks numerous plants, from ornamentals (viburnum, privet, through herbaceous plants (tomato, pumpkin, beet, strawberry and others) and ending on trees (almond, peach and prunus trees in general, salix, citrus and others).

Empoasca decedens: the insect

The insect, as mentioned, is a cicada. At maturity, it reaches 3-3.5 mm in length.

The adult is light green in color with green elytra with transparent wing tips (called chorion). Egg-laying by the females occurs between the leaf veins in an isolated position, After a month has passed the eggs hatch after several stages of development giving rise to the adult insect that we see on the plants and creating damage.

They perform 4-5 generations per year, and the developmental stages may even overlap.

It overwinters on evergreen plants both herbaceous and arboreal, wild and cultivated. It generally spends the spring on herbaceous plants such as tomato, potato, beet, and legumes. Here the first generation originates, in early summer it generally moves onto prunus and in late summer onto herbaceous plants such as strawberries, Finally in September-October, it migrates into citrus groves.

Damage due to Empoasca decedens

Green leafhoppers (or Empoasca decedens) cause damage by sap-sucking and subsequent occlusion of vessels and necrotization of tip areas. From the earliest stages of development on the underside of the leaves and inside the veins, the cicada stings the leaf to feed, thereby creating lesions that will go on to cause abnormalities on the leaves.

Damage to the leaf, and thus to the parenchymatous tissue, is, at times, negligible.

Major damage occurs to the veins with rolling, yellowing, deformation, reduced development, defoliation, and necrosis.

Sometimes phylloptosis (leaf drop) may occur, from the base of the branches toward the apex. The growth of shoots may be slowed down causing internode approximation, and adventitious shoots do not allow proper nutrition of flowering buds.

In young plants, it is dangerous as it causes a slowing of entry into production.

In almond orchards, it causes a reduction in leaf growth, yellowing of leaves that have necrotized margins, and curling of leaves. In general, in both young almond orchards and those in production, growth retardation is observed with delayed entry into production for the former and reduction in vigor and growth in the latter
In peach orchards, sucker bites cause crumpling and curling on the youngest leaves; these then yellow, and desiccate at the apex or margins of the leaf blade. They also induce a reduction in fruit size due to slower development and stunted growth even in the following year’s production due to irregular development of fruiting branches.

On young strawberry trees, they cause damage mainly to young vegetation, and in citrus groves they reduce the accumulation of essential oils in oil glands, causing spot known as “fetula,” which is also present in citrus.

Green leafhopper defense

It is important that defense be carried out following careful monitoring of the presence of this pathogen.
As early as the first decade of June, it will be necessary to perform monitoring with sampling on shoots and/or with yellow chronotropic traps to be placed near the apex of trees.

Phytosanitary treatments are often not effective due to the high mobility of the insects themselves.

There are some products used in conventional such as etofenprox and chlorpyriphos etyl with the persistence of about one week and fenitrothion with greater residual effect. Remember that the use of these products often inhibits the development of entomofauna in the area.

Therefore, limited interventions with these products are recommended. Instead, indirect containment treatments and interventions such as the use of fertilizers that limit the development of leafhoppers are recommended.

For example, Frankyl is an organic fertilizer containing micronutrients (Zinc and Manganese) that helps plants protect themselves from leafhoppers. This can be used together with other products that act by contact, such as pyrethroids, to increase its effectiveness. To be distributed throughout the plant, taking care to wet the leaves on the lower page as well.

From an agronomic point of view, the herbaceous vegetation, where the insect performs its first generation, can be controlled, taking care to maintain shrubby and tree vegetation around, when possible, to prevent it from migrating onto cultivated plants.