Eulecanium coryli
Eulecanium coryli
The Cochineal of the hazelnut (Eulecanium coryli L.) is an insect, rincote homottero, belonging to the Coccidae family.
Systematics –
From the systematic point of view it belongs to the Eukaryota Domain, Animalia Kingdom, Eumetazoa Subarign, Superphylum Protostomia, Phylum Arthropoda, Subphylum Hexapoda, Insecta Class, Subclass Pterygota, Exopterygota Cohort, Subcoorte Neoptera, Suborder Paraneoptera, Section Rhynchotoidea, Section Rhynchotoidea, Section Rhynchotoidea Sternorrhyncha, Coccoidea Superfamily, Coccidae Family and therefore to the Eulecanium Genus and to the E. coryli Species.
The terms are synonymous:
– Eulecanium Bouche horns;
– Lecanium horns Bouche.
Geographic Distribution and Habitat –
The Cochineal of the hazelnut is an insect that lives in temperate climates and in the growth or cultivation areas of: Hazelnut, Pome fruit, Plum, Apricot, Blackthorn, Hawthorn, Rose, Lauroceraso, Forest deciduous trees (Linden, Elm, Maple, Hornbeam).
Morphology –
Eulecanium coryli is a cochineal with clear sexual dimorphism.
The adult female, about 5 mm long, has a brown-fawn colored body, oval in shape, very convex and smooth; after oviposition it tends to flatten and becomes dorsally wrinkled.
The male, about 2.5-2.6 mm in length, is winged, flickers from an elongated follicle, consisting of multiple white and translucent wax plates.
Attitude and Life Cycle –
The Cochineal of the hazel overwinters on the woody organs of plants at the nymph stage.
In early spring or between April-May, depending on the climatic conditions, the sexually mature females and after mating (they are not parthenogenetic) begin to lay eggs.
The eggs remain protected by the maternal body until the nymphs are born.
The nymphs then reach the leaves, fixing themselves on the lower page, where they remain until the beginning of autumn, when they migrate on the twigs to overwinter.
The Eulecanium coryli thus makes only one generation per year.
Ecological Role –
The presence of the nenaids of Eulecanium coryli manifests itself in the lower page of the leaves, from which they subtract sap, producing abundant honeydew; subsequently in the autumn period they migrate on the twigs.
The damage, in addition to the removal of lymph, is due to the abundant production of honeydew which favors the formation of fumaggini and reduces gaseous exchanges, causing asphyxiation.
In the case of severe infestations, vegetative decay can occur on the infested plants, even if normally this cochineal does not cause significant damage.
Especially once the fight against the hazelnut cochineal was a chemical one.
Today it has been seen that, if we do not exceed in crop specializations, agroecological measures are adopted such as greater biodiversity of crops, presence of areas delimited with hedges and low use of nitrogen fertilizers, the populations of the phytophagus are controlled by numerous natural enemies that they manage to prevent the phytophagous from swarming.
Among the entomophages that control this species we remember:
– Coccinellida beetles such as Exochomus quadripustulatus, Chilocorus bipustulatus;
– Calcidoid hymenoptera of the genera Coccophagus, Encyrtus, Aphycus and others.
However, if strong infestations occur, linked to various factors, treatments can be carried out to the escape of the nymphs. The products to be used are the white oils possibly activated with Marseille soap.
Guido Bissanti
Sources
– Wikipedia, the free encyclopedia.
– Russo G., 1976. Agricultural Entomology. Special Part. Liguori Editore, Naples.
– Tremblay E., 1997. Applied entomology. Liguori Editore, Naples.