Institute of Mediterranean Viticulture

Improving knowledge in ecological viticulture

THE ECOLOGICAL VALUE OF THE LANDSCAPE IN BIOLOGICAL CONTROL OF THE GRAPE LEAFHOPPER

 

La Empoasca Vitis (grape leafhopper) is an insect that has a mouthpiece that it uses to suck the phloem from the vine, thereby lowering the content of photoassimilates and causing necrosis in the tissues they feed off. When the population level is high, the vineyard can undergo premature leaf drop and the bunches do not ripen on the plant. Generally speaking, the climatic conditions in wine-growing areas in Spain are not conducive to the spread of the grape leafhopper. Nevertheless, in warm, humid areas such as those found in Enguera, this insect enjoys optimum breeding conditions.

 

The insects which are helpful in controlling this pest are tiny wasps (under 1 mm in length) which lay their eggs in the eggs of the grape leafhopper. According to recent studies, the species that manage to gain control of the pests are those belonging to the genus Angarus and, to a lesser extent, Stethynium triclavatum, although research carried out in Valencia point towards the latter as the possibly decisive species.

 

The monoculture of grapevines is not suitable for these beneficial insects as they find few flowering plant species they can feed on. For this reason, we have introduced an assortment of herbaceous plants and shrubs so as to provide sources of food and shelter for beneficial insects. When strategically placed, these plants flower in a staggered fashion from spring until the end of summer, bestowing a lovely setting on the vineyard. This study aims to assess the role played by the landscape in controlling the grape leafhopper.