Fruit and Vegetables

Metcalfa control

Question: metcalfa control

Every year the olive tree plants are infested with metcalfa and I would like to know how to control this hateful parasite with natural and organic products. Thanks

Answer: metcalfa control

Dear Donatella,
metcalfa is a parasite that arrived in Italy from the American continent; being an insect, in a certain way immigrant, metcalfa does not find any natural antagonist in Europe, except perhaps some birds that seem to feed on adult specimens. The presence of metcalfa in Europe began in Italy, where the insect is widespread, both on crops and on ornamental plants. Although most insects are killed by the treatments used to contain the number of other insects present in the vineyard and in the orchard, the metcalfa has a particular hatching of the eggs, which occurs scalarly for many weeks, which makes it more difficult to contain the number of adults present on the plants; in addition to this, the juvenile forms are covered with a waxy substance, similar to the one that covers the cochineal, which makes them impermeable to many products used in agriculture. The damage caused by metcalfe is often of little consequence, caused by their apparent sucker, which takes the sap of the foliage; these insects digest the proteins contained in the sap, and expel sugars, which are not digested (a little like other insects, such as aphids and cochineal); often the greatest damage is caused by various types of fungi that settle on these sugar residues, called honeydew. In addition to mushrooms, honeydew also attracts bees, which produce excellent honey with honeydew sugars; therefore besides the difficulty of killing the metcalfe covered with wax, there is also the problem of respecting the bees, which in large numbers are attracted by the honeydew. In addition to these problems, the metcalfe at the onset of cold settle in the crevices of the bark, where they survive until the following year; therefore a plant infested this year, it will also be next year if no action is taken. Due to the characteristics of the insect, and the presence of bees in their vicinity, the insecticidal treatments against metcalfa are on the one hand not very effective, and on the other quite inadvisable; they usually occur only in the productive sphere, and only in the case of large infestations by the insect. Typically, more than sprinkle the plants with insecticide, we try to wash away eggs and insects at an early stage, using potassium-based products (eg soft potassium soap). In the last few years the introduction of an antagonist insect, a small hymenoptera that deposits its eggs in the body of adult and young metcalfe, seems to be very successful. this insect is called Neodryinus typhlocybae, and throwing bags containing many insects in various stages of development are available from agricultural consortia or companies specializing in the breeding of insects for biological control.