Lyristes plebejus

Lyristes plebejus

The Italian Cicada (Lyristes plebejus Scopoli, 1763) is an insect belonging to the Cicadidae 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 Homoptera,
Section Auchenorrhyncha,
Infraorder Cicadomorpha,
Cycadidae family,
Subfamily Cycadinae,
Genus Lyristes,
L. plebejus species.
The terms are synonyms:
– Cicada fraxini (Fabricius, 1803);
– Cicada pelebeja Scopoli, 1763;
– Cicada plebeja Scopoli, 1763;
– Cicada plebeja Scopoli, 1763;
– Cicada plebeja subsp. obscura (Fabricius, 1803);
– Cicada plebeja var. martorellii Martorell y Pena, 1879;
– Cicada plebejae Scopoli, 1763;
– Cicada plebia Scopoli, 1763;
– Cicada plebja Scopoli, 1763;
– Fidicina plebeja (Scopoli, 1763);
– Lyristes plebeius subsp. castanea Boulard, 1982;
– Lyristes plebejus (Scopoli, 1763);
– Lyristes plebejus var. castanea Boulard, 1982;
– Psaltoda plebeia (Scopoli, 1763);
– Rihana plebeja (Scopoli, 1763);
– Tettigonia fraxini Fabricius, 1803;
– Tettigonia fraxini Fabricius, 1803;
– Tettigonia obscura Fabricius, 1803;
– Tettigonia plebeja (Scopoli, 1763);
– Tibicen pelbeia Scopoli, 1763;
– Tibicen plebeius Scopoli, 1763;
– Tibicen plebejus (Scopoli, 1763);
– Tibicen plebejus subsp. martorellii Martorell y Pena, 1879;
– Tibicina plebeja (Scopoli, 1763).

Geographic Distribution and Habitat –
Lyristes plebejus is a cicada that lives and reproduces in the countries of southern Europe and Asia. In Europe they are normally found up to the height of southern France and beyond.
Its habitat is typically associated with the Mediterranean maquis, with the presence of olive trees, carob trees and other plants rich in fronds and in drier areas but with the presence of mainly arboreal vegetation.
In general, it is a species that prefers open woods and scrublands, although it can sometimes also appear in agricultural areas, such as olive groves, wheat fields and vineyards. It tends to prefer certain types of trees, namely olive, pine and holm oak.

Morphology –
Lyristes plebejus is a robust cicada, with transparent wings (folded in the shape of a roof), with a wingspan of up to 100 mm, and which can reach up to 35 mm in length.
The eyes are particularly large and well spaced; they are complex (compound eyes) colored green in young animals, blue or dark brown in adult animals.
It also has an orange and angular collar, which delimits the thorax of the head. Characteristic is the white X-shaped design under the chest.
Cicadas are known for their “song” that resonates in the summer.
The song is loud and manages to issue volumes up to 100 decibels at a frequency of 4.3 kHz; given that the females are far from deaf, and are able to perceive sounds above 30 decibels, various other explanations have been put forward to justify these sounds: it is possible that the female chooses the male also based on the intensity of the sound, or that the purpose is to frighten or stun any predators, or instead that the territory to be covered is in fact very large.
The two muscles which with their contraction initiate the chain of events which produces the acoustic impulse, produce a sound having a modulation of 240 Hz. The elastic energy released during these movements generates an acoustic pop, but given the rapidity of the movements, the snap follows a pulse of vibrations characterized by a frequency of 4.3 kHz. The pop realizes very remarkable pressures, being able to touch 160 decibels. The abdominal region usually contains an air sac, as well as a pair of eardrums which act as sound boxes, which connect the sac with the outside and are able to amplify the sound about 20 times. The abdominal apparatus is used to correct the acoustic system to optimize sound quality.

Attitude and biological cycle –
Lyristes plebejus is a hemimetabolous insect that goes through five larval stages separated by moults, during which it gradually becomes more and more similar to the adult animal. They gradually grow larger and, with age, form and enlarge attachments for wings and genital armor.
The underground leafhopper larvae suck sap from plant roots. In order to move better underground, their front legs have been transformed into digger legs.
When the weather is favourable, usually at the beginning of August, they leave the ground by making a hole and look for suitable spots in the surrounding vegetation. There they mutate one last time to become a full insect.
Newborn adult animals are initially soft and greenish. They need about four to five days before they are fully colored and the chitin shell is fully hardened.
The life cycle of this species is estimated to last about three years.
As mentioned, it is only the adult males that produce acoustic signals, which they use to attract the females during the mating season, which generally runs from June to the end of August.

Ecological role –
The Lyristes plebejus is an insect that characterizes, in the summer period, entire territories so much that it also belongs to some folkloristic events such as the Provençal one in the south of France.
These insects fly away when threatened; they expel a secretion from the abdomen, which may consist of aspirated vegetable juices and is intended to frighten the enemy.
Like all cicadas they live like suckers on the xylem. With the help of their trunks, adult animals drill through the wood of various trees and suck out plant sap, rich in nutrient salts and water. The underground larvae suck sugar-rich plant sap from the roots.
From an ecological point of view, this cicada was particularly abundant in the 60s and 70s, a little throughout Europe, but in the last few decades there has been a very clear decline, most likely due to the use of various pesticides and the change agricultural systems that from extensive have become specialized and monoculture.

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/296165227/original.jpeg