Corythucha ciliata

Corythucha ciliata

The Sycamore Lace Bug (Corythucha ciliata Say, 1832) is an insect belonging to the Tingidae family.

Systematics –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Subkingdom Eumetazoa,
Bilateria branch,
Phylum Arthropoda,
Subphylum Hexapoda,
Class Insecta,
Subclass Pterygota,
Exopterygota cohort,
Subcohort Neoptera,
Superorder Paraneoptera,
Rhynchotoidea Section,
Order Rhynchota,
Suborder Heteroptera,
Infraorder Cimicomorpha,
Superfamily Tingoidea,
Family Tingidae,
Genus Corythucha,
Species C. ciliata.
The term is basionym:
– Tingis ciliata Say, 1832.

Geographic Distribution and Habitat –
Corythucha ciliata is a heteroptera and phytophagous insect of forest plants.
Its main host is Platanus occidentalis but it also lives on Broussonetia papyrifera, fraxinus sp. and other hardwoods.
This insect is native to North America but is also present in other areas of the continent, such as Mexico where it is widespread in the states of Coahuila, Nuevo León and Tamaulipas.
Furthermore, it has been introduced for over half a century in a good part of Europe, especially in the southern and central area, where it mainly attacks the plane tree.
It has been known in Italy since 1964, where it is now widespread in Lombardy, Liguria, Veneto, Emilia, Lazio and Tuscany.

Morphology –
The Corythucha ciliata, in the adult state (about 4 mm in length) is recognized for having a shiny black body. It also has a widely expanded yellowish pronotum in a lattice pattern on the transparent sides.
The front wings are sub-quadrangular in shape and show a grid with quadrangular or pentagonal meshes
The nymphs are characterized by small yellowish legs and antennae; they never move from the leaf on which the eggs from which they hatched were located.
Nymphs begin to develop wing tips, are dark gray in color and tend to move towards less populated leaves.

Attitude and biological cycle –
The Corythucha ciliata is an insect that overwinters in the adult stage, sheltered under the plates of the bark of the host plants, or in other ravines.
Once they arrive in spring, usually after the second fortnight of April, the wintering adults resume their activity, going to colonize the new vegetation.
In the period of May, they begin to ovipose, originating the first generation which is active at the beginning of the summer.
The females stick the eggs in the mesophyll, for about two thirds of their length, and cover the protruding part with blackish excrement; these determine a blackish punctuation on the underside of the leaves.
The first eggs are then laid on the leaves of the plane trees, glued along the bifurcations of the veins, on the underside of the leaves. After 20-30 days the nymphs are born which at the end of June are already adults and in turn lay eggs in July and August giving rise to another two generations. In October, the adults return to their winter shelters.
In this way the Corythucha ciliata completes 3 generations a year.

Ecological Role –
Corythucha ciliata is an insect that has a stinging sucking mouthparts in all stages; the insect stings the mesophyll and empties the cell which fills with air and necrotizes. On the upper page there is a typical symptomatology; this manifests itself with an intense chromatic alteration of a silvery color, located above all in the central part of the leaf, near the petiole. The silvery part subsequently becomes yellowish and chlorotic, until necrotic.
For this reason the insect causes a lot of damage to infested plants. The insect is also very annoying for humans, especially infesting streets and avenues.
It should be remembered that among the natural enemies there are some ide parasites; in Italy it is attacked by a predatory Anthocoride: the Orius laticollis, which preferably lives off the juvenile stages of the insect.
Other enemies are also of the genus Anthocoris and Chrysopid Neuroptera.
The infestations, up to now, have been controlled by acting with contact insecticides against the nymphs. In this case it is useful to operate above all in the period between the end of May and mid-July when the foliar vegetation has not yet fully developed allowing easy wetting. It is useless to attack the eggs, which are hardly devitalized, and the adult specimens, which fall to the ground if disturbed by the nebulizer.
However, this struggle is somewhat difficult due to the urban context in which the Platani are normally found and due to the large dimensions they reach.
Add to this the indirect effect of these insecticides on other components of the fauna, as well as humans.
Experimentally, alternative interventions to spraying the foliage with injections of insecticide solutions have been tried; the results, as already mentioned in relation to the fight against anthracnose, are not always standardizable.
If you are in a nursery or in other rather peripheral contexts, it is still possible to carry out a direct intervention on the foliage. The intervention must be carried out against the first juvenile stages of the 1st generation, in order to immediately reduce the infestation potential.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Russo G., 1976. Agricultural entomology. Special Part. Liguori Publisher, Naples.
– Pollini A., 2002. Handbook of applied entomology. Edagricole, Bologna.
– Tremblay E., 1997. Applied entomology. Liguori Publisher, Naples.

Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/251013985/original.jpeg