Doratura exilis Horváth, 1903

Bückle, Christoph & Guglielmino, Adalgisa, 2022, Revision of the genus Doratura Sahlberg (Hemiptera, Cicadellidae, Deltocephalinae) with particular regard to its distribution in Italy and description of four new species, Zootaxa 5112 (1), pp. 1-116 : 14-16

publication ID	https://doi.org/ 10.11646/zootaxa.5112.1.1
publication LSID	lsid:zoobank.org:pub:C2750D92-315A-431F-BCEB-3E20ECD03EA0
DOI	https://doi.org/10.5281/zenodo.6954628
persistent identifier	https://treatment.plazi.org/id/039C8791-BF70-157E-E8B8-87DEBFC33077
treatment provided by	Plazi
scientific name	Doratura exilis Horváth, 1903
status

Treatment

( Figs 2B View FIGURE 2 ; 4B View FIGURE 4 ; 7A, B View FIGURE 7 ; 9B, C View FIGURE 9 ; 10H, I View FIGURE 10 ; 11D View FIGURE 11 ; 12E, F View FIGURE 12 ; 19B View FIGURE 19 )

Doratura exilis Horváth, 1903b: 454

Doratura (Doratura) exilis Emeljanov, 1964: 403

Diagnosis. Small species with proportionally short fore wings without green tinge ( Figs 7A, B View FIGURE 7 ), and genital morphology similar in every regard to D. stylata , but never with spinules on the ventral margin of the aedeagus ( Figs 10H, I View FIGURE 10 ). The nymphs display two broad longitudinal dark stripes on their abdomen ( Fig. 9B View FIGURE 9 ), which distinguishes this species from both D. impudica and D. stylata .

Distribution ( Figs 54 View FIGURE 54 , 56 View FIGURE 56 , 57 View FIGURE 57 , 63 View FIGURE 63 ). In Italy, we found this species in Friuli-Venezia Giulia, Marche, Latium, and Abruzzo. Furthermore, Remane & Hellrigl (1996) record the species from Alto Adige.

The species is widespread in Europe and the East Palearctic region to Mongolia and is also recorded from the Near East ( Armenia). We studied specimens from Bulgaria, Czech Republic, France, Germany, Greece, Hungary, Italy, Romania, Slovakia, Slovenia, Ukraine. In addition, there are records from Albania ( Dlabola, 1964); Andorra ( Nast, 1972); Armenia ( Lindberg, 1960); Austria ( Holzinger, 2009); Belarus ( Borodin, 2004); Belgium ( Van Stalle, 1989); Bosnia and Herzegovina ( Horváth, 1903b); Estonia ( Söderman et al., 2009); Finland ( Söderman et al., 2009); Iran (Mozzafarian & Wilson, 2016); Kazakhstan ( Mitjaev, 1971); Kyrgyzstan ( Novikov et al., 2006); Latvia ( Vilbaste, 1974); Lithuania ( Vilbaste, 1974); Moldova ( Nast, 1987); Mongolia ( Dlabola, 1965); Montenegro ( Krstić et al., 2012); Poland ( Dworakowska, 1968); Portugal ( Quartau & Duarte Rodrigues, 1969); Russia: European part ( Emeljanov, 1964), Altai Mts. ( Vilbaste, 1965), Siberia: Omsk ( Horváth, 1903b); Serbia ( Horváth, 1903b); Sweden ( Ossiannilsson, 1983); Switzerland ( Mühlethaler et al., 2017). The record supposed by Metcalf (1967) to concern the Netherlands ( Reclaire, 1944) actually refers to Germany.

Remark 1. In some cases, D. stylata and D. exilis are not easily distinguishable as their morphometric characters may overlap. In populations from the Central Apennines ( Italy) and the Peloponnese Peninsula ( Greece), for example, frequently specimens occur that display measurements somewhat different in respect of the values indicated in the literature and in our key; the overlapping range with D. stylata becomes in these cases quite wide. Nevertheless, specimens of such populations can generally be distinguished even from small D. stylata specimens using some further characters (in addition to the characters used for the distinction of the two taxa in the identification keys, prevalently morphometric characters: D. exilis is smaller, rather slender, with proportionally short fore wings), even if none of them alone is exclusive for one species or present in each specimen. Such characters concern above all the coloration and the markings. Distinct green coloration of the fore wings is typical for D. stylata , lack of such coloration for D. exilis (no specimen in our D. exilis material had a green tinge on the fore wings, but D. stylata may lack it as well). Brown stripes on the wings, particularly along the border of the clavus are typical for D. exilis but may occur also in D. stylata . The middle row of transverse spots on the vertex is present nearly exclusively in D. stylata (almost never in D. exilis ), but may also be absent (above all in females). A brown not exactly delineated central square spot in the middle of the vertex near its hind margin, often divided in two small longitudinal stripes and a poorly defined brown sagittal band on pronotum and/or scutellum are often present in D. exilis (above all in males). In contrast, they are generally absent in D. stylata , and present only in very dark specimens (see also the drawings given in Dworakowska, 1968, and in Biedermann & Niedringhaus, 2004). Of course, the pattern given here for D. exilis can be observed in other taxa as well (for example D. homophyla , or in the D. paludosa group), but these taxa have a very different genital morphology.

Remark 2. Servadei (1967) regarded D. exilis as a synonym of D. stylata .

Remark 3. Ossiannilsson (1983) mentions that the saw-case of the ovipositor (gonoplac, 3 rd valvula) is comparatively longer in D. exilis than in D. stylata . Similarly, we found the serrated portion of the 2 nd valvula and the number of teeth ( Figs 4A, B View FIGURE 4 ) in both species approximately the same though D. exilis is distinctly smaller than D. stylata . In addition, the serrated part of the 2 nd valvula is somewhat slenderer in the former species than in the latter.

Ecology. The species is typically found on dry pastures, in northeastern Italy at low altitude on karst or sandy places, in the Apennine and Balkan Peninsula often in mountain pastures. Subspecies of the Festuca ovina group are recorded as host plants ( Nickel, 2003).

Phenology. The species occurs at least from the end of May until the end of September. In warm lowland regions it may be bivoltine.