Salicarus nitidus ( Horváth, 1905 )

Konstantinov, Fedor V. & Hosseini, Reza, 2024, Review of the genus Salicarus (Hemiptera, Heteroptera, Miridae), ZooKeys 1211, pp. 57-100 : 57-100

Salicarus nitidus ( Horváth, 1905)

Figs 3 I, G , 5 H, I , 8 D, E, I , 9 G – I

Atractotomus nitidus Horváth, 1905: 275.

Heterocapillus nitidus : Wagner (1975 a): 127 (key, description, figures); Heckmann et al. (2015): 95 (figure of vesica).

Salicarus nitidus : Konstantinov (2023): 861 (phylogenetic placement, figures, discussion).

Material examined.

Holotype: Spain • Castile-La Mancha: ♀ Pozuelo de Calatrava 38.91 ° N, 3.84 ° W, Collection date unknown, José María de la Fuente ( HNHM) (not seen; pictures of the head and habitus in dorsal and lateral views were examined).

Other specimens examined: France • Corse (Corsica): Costa , 42.0333 ° N, 8.95 ° E, 19 Jul 1963, Unknown collector, 1 ♀ ( AMNH _ PBI 00336969 ) ( ZMUH) • Tiuccia , 42.06566 ° N, 8.73889 ° E, 10 m, 19 Jun 1961, J. Péricart, Calicotome villosa ( Fabaceae ), 1 ♂ ( AMNH _ PBI 00336961 ), 1 ♀ ( AMNH _ PBI 00336968 ) ( ZMUH) • Midi-Pyrenees: Vernet , 43.18305 ° N, 1.6 ° E, 700 m, 06 Jun 1962, J. Péricart, 1 ♂ ( AMNH _ PBI 00336964 ) ( ZMUH) .

Diagnosis.

Recognized by the small, stumpy, uniformly dark brown body, total length male 2.3–2.6, female 2.2–2.4; dorsum with dense, wide, and apically serrate scale-like setae, femora also clothed with scales (Fig. 3 I, G ); antennal segment II distinctly fusiform, at midpoint male 1.4–1.5 ×, female 1.6–1.7 × as wide as segment I at apex (Fig. 5 H, I ); apical blades of vesica long, gradually curving, closely located but separate, not adjoining each other (Fig. 8 D, E, I ).

Most similar to S. perpusillus in size, body proportions, and the distinctly fusiform antennal segment II in both sexes, as well as the presence of scale-like setae on femora (although scales are absent on the bases of tibiae and antennae). However, it differs from this species, as well as from S. cavinotum and S. genistae in the vesica structure with apical blades that are not tightly adjoining. Additionally, S. nitidus is the only one of the closely related species mentioned above that feeds on Calicotome rather than Genista spp. Refer to the diagnosis of S. genistae for additional discussion.

Redescription.

Male. Coloration. Dorsum and venter uniformly brown to dark brown (Fig. 3 I ). Head: Brown to dark brown, apices of labial segments I and II usually pale brown; antennal segments III and IV uniformly pale yellow. Thorax: Brown to dark brown, tibiae dirty yellow, with round spots at bases of tibial spines, very small on fore and middle tibiae, distinct on hind tibia; tarsi pale yellow, with darkened apices; membrane and veins uniformly brown. Abdomen: Uniformly dark brown.

Surface and vestiture. Smooth, moderately shiny; dorsum, thoracic pleura, femora, and abdomen with dense, silvery, broad and apically serrate scale-like setae and adpressed to semierect, long, almost twice as long as scales, simple setae, dark on cuneus and apex of corium, yellowish elsewhere; series of long simple setae on fore coxa silver; sides of pronotum and hemelytron at base with robust, long, erect to semierect, black bristle-like setae.

Structure. Body 2.5–2.7 × as long as posterior width of pronotum; total length 2.3–2.6; vertex 2.3–2.6 × as wide as eye; antennal segment II distinctly fusiform, 1.4–1.5 × as wide at midpoint as segment I at apex, 4.1–4.3 × as long as wide, 0.5–0.6 × as long as posterior width of pronotum, 0.7 × as long as width of head; pronotum 2.1–2.3 × as wide as long, 1.3 × as wide as head.

Genitalia. Right paramere spoon-shaped, with long, straight, and blunt apical process (Fig. 9 G ). Right paramere with thin, short, and straight apical process and broadly rounded sensory lobe (Fig. 9 H ). Vesica with very long, gradually curving, apical blades, closely located but separate, not adjoining each other (Fig. 8 D, E, I ).

Female. Coloration, surface, and vestiture. As in male (Fig. 3 G ).

Structure. Body 2.3–2.5 × as long as posterior width of pronotum; total length 2.2–2.4; vertex 2.4–2.6 × as wide as eye; antennal segment II somewhat wider than in male, 1.6–1.7 × as wide at midpoint as segment I at apex, 4.0–4.1 × as long as wide, 0.6 × as long as posterior width of pronotum, 0.7 × as long as width of head; pronotum 2.2–2.3 × as wide as long, 1.3–1.4 × as wide as head.

Genitalia. Dorsal labiate plate with large and wide, broadly oval at base, apically tapering sclerotized rings.

Distribution.

Ciudad Real province of Spain ( Wagner 1975 a: Pozuelo de Calatrava), southern France ( Wagner 1975 a: Corsica ), southern Italy ( Carapezza 1984: Sardinia; Carapezza 1993: Aeolian Islands).

Host.

Calicotome villosa (Poir.) Link. ( Wagner 1975 a) . Genista corsica (Loisel.) DC was reported as a host from Sardinia ( Carapezza 1984) and Genista ephedroides DC. from Aeolian Islands ( Carapezza 1993). However, the last two records may pertain to S. perpusillus and require further confirmation ( Carapezza 1995).

Discussion.

Salicarus nitidus ( Horváth, 1905) belongs to a group of four hardly distinguishable species with a complex taxonomic history, which also includes S. cavinotum ( Wagner, 1973) , S. genistae ( Lindberg, 1948) , and S. perpusillus ( Wagner, 1960) . These species inhabit the North Mediterranean, from central Spain in the West to Cyprus in the East. Horváth (1905) described Atractotomus nitidus based on a single female from central Spain and noted its similarity with Atractotomus (currently Heterocapillus ) tigripes (Mulsant & Rey, 1852) due to its overall appearance and coloration, as well as the presence of large dark spots at bases of tibial spines. He distinguished A. nitidus by its much smaller size (2.25 mm), less fusiform antennal segment II, and tibiae not darkened ventrally.

Lindberg (1948) described A. genistae from a series of specimens collected in two localities in Cyprus. He emphasized the similarity of the new species to Atractotomus mali (Meyer-Dur, 1843) due to the spindle-shaped antennal segment II in both sexes. According to the original description, the new species differs in having a dark-colored membrane, dark spots at the bases of tibial spines, smaller size, and a shorter segment II, which is distinctly shorter than the head width. Lindberg (1948) did not mention A. nitidus in his diagnosis and was apparently unaware of this species.

Wagner (1960) described Atractotomus perpusillus from Sierra Nevada (southern Spain) as the smallest species of the genus (2.1–2.4 mm), most similar to A. parvulus Reuter, 1878 , but differing from that species in having wide scale-like setae, a spindle-shaped antennal segment II, and a long and thin apical process of the vesica. Wagner also noted that the dorsal vestiture of A. perpusillus , with three types of setae, separates it from all congeners except A. tigripes . To accommodate these two species and A. putoni Reuter, 1878 (subsequently synonymized with A. validicornis Reuter, 1876 ), he erected the subgenus Heterocapillus Wagner, 1960 which was later upgraded to a valid genus by Kerzhner (1962). The last species of this group, Heterocapillus cavinotum , was described by Wagner (1973) from Rhodos Island ( Greece). According to the original description, this species is most similar to H. nitidus and H. perpusillus but differs from both in having a pair of rounded pits on the pronotum, and a set of minor distinctions some of which, such as body length, appear to contradict with provided measurements.

In his monographic treatment of Mediterranean plant bugs Wagner (1975 a) formulated the species concepts of these four closely related species as follows:

Heterocapillus genistae ( Cyprus, on Genista sp. ): relatively large, body length male 2.5 mm, female 3.0 mm, antennal segment II slightly spindle-shaped in male, distinctly spindle-shaped in female.

Heterocapillus cavinotum (Rhodos Island, on Genista spp. ): body length male 2.35 mm, female 1.9 mm, pronotum with a pair of pits, antennal segment II distinctly spindle-shaped in both sexes, 3.8–4.0 × as long as wide at middle.

Heterocapillus nitidus (central Spain, Corsica , on Calicotome villosa ): body length male 2.5 mm, female 2.2–2.3 mm, antennal segment II spindle-shaped in both sexes, male 4 ×, female 3.9 × as long as wide at middle.

Heterocapillus perpusillus (southern Spain, southern France, on Genista sp. ): body length male 2.1 mm, female 2.3–2.4 mm, antennal segment II spindle-shaped in both sexes, male 4.2 ×, female 4.0 × as long as wide at middle.

Since then, H. cavinotum was additionally reported from Peloponnese peninsula and Crete ( Linnavuori 1999; Kment et al. 2005), while the presence of pits on the pronotum in this species was refuted ( Linnavuori 1999). Heterocapillus nitidus was additionally indicated from Sardinia and Aeolian Islands ( Italy, Carapezza 1984, 1993), while H. perpusillus from Laconia ( Greece, Rieger 2012) and Crete ( Heckmann et al. 2015). A synonymy of H. perpusillus with H. nitidus was suspected by Goula and Ribes (1995), but Heckmann et al. (2015) noted slight distinctions in the size and shape of the vesica between these two species. Konstantinov (2023) transferred all these species to Salicarus . Examination of all available material allows us to conclude that despite the notable similarity, all four species could be distinguished from each other by the combination of characters provided in the key to species and diagnoses. Molecular data are desirable for elucidating the status of these species. Pending such a study, we refrain from nomenclatorial changes.

Figures

Figure 3. Dorsal habitus A, B ♂ Salicarus urnammu C, D ♀ S. urnammu E ♂ paratype of S. cavinotum F ♀ paratype of S. cavinotum G ♂ S. genistae H ♀ S. genistae I ♂ S. nitidus G ♀ S. nitidus K ♂ holotype of S. perpusillus L ♀ S. perpusillus.

Figure 5. Head, pronotum, and vestiture A, B paratype of Salicarus cavinotum, head and pronotum in dorsal view: A ♂ B ♀ C, G S. genistae, head and pronotum in dorsal view: C ♂ G ♀ D – F paratypes of S. perpusillus: D ♂ head and pronotum in dorsal view E ♀ head and pronotum in dorsal view F ♀ vestiture on dorsum and legs H – I S. nitidus, head and pronotum in dorsal view: H ♂ I ♀.

Figure 8. Vesica A Salicarus cavinotum, paratype B, C S. genistae D, E S. nitidus F, G S. perpusillus, paratype H, I apical part of vesica enlarged: H S. genistae I S. nitidus.

Figure 9. Male genitalia A – C Salicarus concinnus, paratype D – F S. genistae G – I S. nitidus J – L S. fulvicornis M – O S. halimodendri, paratype P – R S. roseri S – U S. urnammu A D G J M P S: right paramere B E H K N Q U: left paramere C F I L O R U: apex of phallotheca.