Stephanitis pyri
Stephanitis pyri
The Pear tingide (Stephanitis pyri (Fabricius, 1775)) 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,
Subfamilies Tinginae,
Tingini tribe,
Genus Stephanitis,
S. pyri species.
The term is basionym:
– Acanthia pyri Fabricius, 1775.
The term is synonymous:
– Tingis pyri (Fabricius, 1775).
Two subspecies are recognized within this species:
– Stephanitis pyri subsp. pyri;
– Stephanitis pyri subsp. sareptana Horváth, 1912.
Geographic Distribution and Habitat –
Stephanitis pyri is a rhincote that is found in North Africa, central and southern Europe and Asia.
It is a phytophagous and polyphagous insect that lives in particular, as regards crops of agricultural interest, on apple and pear trees but also frequents cherry, plum, hazel, currant, azalea, rhododendron, etc.
Morphology –
Stephanitis pyri is a small insect whose adults measure 3 – 3.3 mm in length and flattened in shape.
These have a dark, flattened body with two typical semicircle expansions of the pronotum.
On the anterior part of the thorax and on the elytra there are expansions with a reticulated appearance. With closed wings, which are transparent, it is possible to see a black spot transversal to the H-shaped body; moreover, together with the front wings lying horizontally on the body, it has a typical dense reticulation which divides the wings and prothoracic expansions into polygonal cells. The wings are more outstretched than the body.
The nymphs are apterous, have a black head with some kind of thorns; the abdomen is clear with dark spots and with the presence of light thorns.
The nymphs, similar in appearance and slightly larger than the nymphs, have black wing sketches.
Attitude and biological cycle –
Stephanitis pyri is an insect that winters as an adult in the ravines of the bark or in various other shelters that the orchard offers, such as the dry vegetation at the base of the plants.
Once the spring period has arrived, but with the first warmth, the adults resume their activity very early, that is, towards the first or second ten days of April.
The females begin to ovipose from the end of April to the beginning of May on the new vegetation, driving the eggs into the leaf tissues on the sides of the median vein and covering them with a black liquid.
From these eggs originates the first generation which takes place between May and June.
The nymphs are born after about a month while the adults of this first generation appear after about 20 days from the birth of the nymphs. The adults mate starting a second generation, which appears about 2 weeks after the oviposition.
The first generation thus follows a second generation: in the middle of summer, between June and July and a third generation: at the end of summer, August; in some environments, with particularly favorable climates, there may also be a fourth generation which occurs towards the end of summer or beginning of autumn.
However in colder climates there may be only two generations.
In this way the Stephanitis pyri completes, therefore, 3 or 4 generations per year.
Ecological Role –
Stephanitis pyri is a heteropteran ryncote that was first described by Johan Christian Fabricius in 1775.
This rincote, despite being polyphagous, has apple and pear as its primary hosts.
These insects colonize, in all stages, the lower leaf page; this is dotted with black due to bites from oviposition. The females, in fact, lay oviposition in the leaf mesophyll, leaving outside a portion of the egg which they cover with blackish excrements.
Furthermore, on the lower page there are also the residues of the insect’s metabolic activity, such as the whitish exuviae of the various moults.
Finally, the mobile forms are clearly evident on the infested leaves: adults and nymphs stationed on the underside.
The damage is caused both by the adults and by the nymphs which, by stinging the leaves and emptying the mesophyll, cause the appearance of yellow-silver dots on the upper page; these punctuations often converge in large areas, especially centered near the main ribs. In the event of an intense attack, necrotization of the entire leaf may occur.
Furthermore, in the case of heavy infestations, the bites from oviposition and the abundant excrements that cover them carry out an asphyxiating action which, together with the damage from trophic bites, can cause early phylloptosis.
Generally, this Tingide is almost absent in production plants while it is present in small orchards, or in neglected ones.
The fight against this tingide up to now has been of a chemical type even if it is almost never carried out specifically. In fact, as a rule, the treatments that are made against the other pests of the pear tree are sufficient to control the population. In case of strong and sudden attacks it is advisable to intervene, in the moment of maximum presence of the nymphs and especially for those of the first generation.
The control of these insects and their proliferation can be controlled with particular agronomic techniques and, above all, in the planning phase of the plants, excluding the high cultural specializations, above all on vast areas, increasing the tree associations with species not subject to the Tingide, preparing , where possible hedges and low walls as useful shelters for its predators.
Among the natural enemies are in fact to be mentioned the Anthocorid Rhynchotes (especially the genus Orius) which are predators of mobile forms, and some predatory Myridae (such as Stethoconus cyrtopeltis Flor).
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/183777853/original.jpg