Dariella, Namyatova & Cassis, 2021

Namyatova, Anna A. & Cassis, Gerasimos, 2021, Five new genera of the subfamily Cylapinae (Insecta, Heteroptera, Miridae) from Australia, ZooKeys 1012, pp. 95-134 : 95

Dariella gen. nov.

Type species.

Dariella rubrocuneata sp. nov. by original designation.

Diagnosis.

Dariella differs from other Cylapinae in the following combination of characters: macropterous; vertical head with antennal fossa placed above mandibular plate (Fig. 3A ); elongate body, covered with short adpressed simple setae; pronotum, corium, and clavus deeply punctate (Fig. 3B, M ); eye not pedunculated; vertex carinate posteriorly (Fig. 3B ); base of pronotum wider than head; total antennal length shorter than body; antennal segment II slightly incrassate towards apex; antennal segments III and IV each shorter than segment II (Fig. 3E ); buccula ring-like (Fig. 3A ); apex of labium slightly surpassing posterior coxae; segments I and II not subdivided (Fig. 3D ); collar delimited with deep groove (Fig. 3A, B ); calli distinct with round shallow pit between them; scutellum flat (Fig. 3E, M ); metathoracic scent gland evaporative area only slightly longer than wide with distinct vertical grove behind peritreme (Fig. 3F ); outer margin of hemelytron slightly constricted anteriorly (Fig. 1 ); widest part of embolium subequal to 1/3 cuneus width at base; cuneus longer than wide at base (Fig. 3L ); tarsal segment I shorter than segments II and III each (Fig. 3J ); middle row of tiles on unguitractor reduced (Fig. 3K ); parameres subequal in length and both with swelling in basal half directed outwards (Fig. 4D, F ); phallotheca more extensively sclerotised apically, than basally; endosoma with single sclerotised area placed at right hand side (Fig. 4A, B ).

Description.

Male. Coloration (Fig. 1 ). Head, pronotum, mesoscutum, scutellum mostly brown to dark brown; hemelytron, labium and appendages mostly pale brown to yellow with reddish tinge. For details see species description. Surface and vestiture. Dorsum shiny, without net-like pattern of microsculpture; posterior part of pronotum, clavus and corium with deep punctures (Fig. 3B, M ); scutellum mostly smooth, serrate laterally (Fig. 3M ); head, calli, embolium, cuneus and pleura smooth (Fig. 3B, F, L ); dorsum and legs clothed with adpressed short simple setae, those setae on head and pronotum sparse; head with long suberect seta near inner margin of each eyes in dorsal view (Fig. 3B, C ); antennae clothed with suberect setae mostly as long as or longer than antennal segment II width (Fig. 3E ); anterior part of mesopleuron with area of dense short adpressed setae; posterior part of mesopleuron and metapleuron with sparse semi-adpressed setae (Fig. 3F ). Structure. Head. Vertical, in dorsal view wider than long; eye not covering anterior margin of pronotum, not protruding; vertex carinate posteriorly (Fig. 3B ); in anterior view head wider than high; antennal fossa attached near ventral margin of eye; clypeus separated from frons with shallow depression, its base placed slightly below ventral margin of eye (Fig. 3C ); in lateral view head twice as high as long; eye slightly upraised above vertex, covering lateral margins of pronotum; distance between eye and ventral margin of head subequal to half of eye height; antennal fossa adjacent to eye, placed slightly above mandibular plate; mandibular and maxillary plates separated from head by shallow depression posteriorly; labrum triangular, shorter than labial segment I (Fig. 3A ); buccula twice as long as high, ring-like, almost reaching posterior margin of head (Fig. 3A ). Antenna (Fig. 3E ). Shorter than body, segment I shorter than head width; segment II longer than head width, slightly incrassate apically; segment III subequal to half of segment II; segment IV ca. 1.5 × as long as segment III; segments I and II subequal in width and wider than segments III and IV each. Labium (Fig. 3D ). Apex slightly surpassing hind coxa, its segments not subdivided; labial segment I surpassing base of forecoxa; labial segments I-III subequal in length; segment IV slightly shorter than segment III. Thorax. Pronotum wider than long, lateral margins concave in dorsal view, not carinate (Fig. 3A, B ); collar delimited with deep sulcus, as wide as antennal segment I; posterior margin rounded and convex; calli swollen, occupying less than half of pronotum, separated from each other by depression and round pit (Fig. 3B ); scutellum flat; mesoscutum almost entirely covered with pronotum (Fig. 3E, M ); propleural apodeme mostly straight, its apical part inclined anteriorly and merging with collar sulcus; mesopleural apodeme oval; mesothoracic spiracle slit-like, without microsculpture around it; metathoracic scent gland evaporative area large, lateral margin reaching base of hind coxae, triangular, with distinct vertical groove; peritreme only slightly upraised, elongate; metepimeron subequal to 1/4-1/3 of mesopleuron in width (Fig. 3F ). Hemelytron. Outer margin of hemelytron slightly constricted anteriorly (Fig. 1 ); ridge on clavus shallow, almost indistinct; claval commissure slightly more than twice longer than scutellum; medial fracture distinct, surpassing middle of corium (Fig. 3M ); ridge along medial fracture absent; embolium wide, its widest part subequal to 1/3 of cuneus width at base; R+M more distinct basally; cuneus delimited with small incision, longer than wide at base; membrane with single cell, distance from cell apex to membrane apex subequal to cell length (Fig. 3L ). Legs. Forecoxa length shorter than pronotum; coxae subequal in width and length; femora regular, not specifically widened; fore- and hind femora slightly wider than middle femur (Fig. 3G ); segments II and III of hind tarsus subequal in length and each of them twice longer than segment I (Fig. 3J ); claw with small subapical tooth; medial row of tiles on unguitractor reduced, having less tiles than lateral rows (Fig. 3K ). Genitalia. See species description.

Female. Unknown.

Etymology.

The genus is named after the sister of the first author (AN), Daria Namyatova. The gender is feminine.

Remarks.

According to the present classification ( Gorczyca 2000), Dariella does not belong to any Cylapinae tribe. It is similar to Cylapini and Bothriomirini in having punctate body (Fig. 3B, M ), vertical head with antennal fossa placed above mandibular plate (Fig. 3A ), and not subdivided labial segments I and II (Fig. 3D ). See also Wolski (2017) and Namyatova et al. (2019) for detailed diagnoses of Cylapini and Bothriomirini respectively. However, most Cylapini species have antennae as long as or longer than body and antennal segments III and IV each longer than segment II ( Wolski 2017), whereas in Dariella the antennae are shorter than body, and antennal segment III is shorter than segment II. In Bothriomirini , the body is more or less oval and stout, the collar is not delimited or weakly delimited, the scutellum is punctate, the tarsal segments are subequal in length ( Namyatova et al. 2019), whereas in Dariella the body is elongate (Fig. 1 ), the collar is delimited with the deep sulcus (Fig. 3B ), the scutellum is impunctate (Fig. 3M ), and the tarsal segment I is shorter than each of segments II and III (Fig. 3J ). Currently, we place Dariella in Cylapini , as it has affinities to some of its members, which also do not fully fit the diagnoses provided by Gorczyca (2000) and Wolski (2017).

Dariella is similar to the Neotropical genera Corcovadocola Carvalho, 1948 and Cylapoides Carvalho, 1952 as they also have short antennae ( Carvalho 1948, 1952). Additionally, both those genera have a carinate vertex, apex of the labium reaches at least the hind coxa, and possess more or less developed calli. Corcovadocola and Cylapoides differ from Dariella in a convex scutellum and antennal segment III subequal in length to segment II. Corcovadocola additionally differs from Dariella in the lateral sides of pronotum being slightly carinate, and the narrower embolium. Cylapoides additionally differs in the eyes slightly pedunculate, the head width subequal to pronotum width and the cuneus as long as wide at the base ( Carvalho 1952; Wolski 2017). Dariella is also similar to another Neotropical genus Cylapinus , as they both have a punctate body, wide embolium and pit between calli and very similar shape of parameres with the left and right parameres subequal in length and the basal half of both parameres with swelling directed outwards (Fig. 4B, F ; Carvalho 1986: figs 12, 13). Cylapinus differs from the new genus in the body covered with erect setae and the cuneus being as long as wide ( Carvalho 1986).

Dariella can be easily recognised externally from two Australian genera Carvalhoma Slater & Gross, 1977 and Schizopteromiris , currently placed in the Cylapini , as Carvalhoma has staphylinoid hemelytra and Schizopteromiris Schuh, 1986 has coleopteroid hemelytra in both sexes ( Schuh 1986; Namyatova and Cassis 2016a). However, those two genera are similar to the new genus in having the antenna shorter than the body, a similar vertical head and punctate hemelytron. Additionally, Carvalhoma has a similar left paramere with the basal half having swelling directed outwards and the phallotheca sclerotised apically ( Namyatova and Cassis 2016a), and most species of Carvalhoma also have the endosoma with the sclerite placed at right side, which is very similar to Dariella (cf. Fig. 4A, B ; Namyatova and Cassis 2016a: figs 7A, B, 9A, B, 10A, B). Another character uniting Carvalhoma , Schizopteromiris and Dariella is the reduced middle row of tiles on the unguitractor (Fig. 3K ; pers. obs. for Schizopteromiris ; Namyatova and Cassis 2016a: fig. 2L). Schizopteromiris might be closely related to Dariella , as they both have paired setae near the inner margin of eye dorsally (Fig. 3B, C ; pers. obs. for Schizopteromiris ) and a very similar shape of the metathoracic scent gland evaporative area which is slightly longer than wide with distinct vertical grove behind peritreme (cf. Fig. 3F and Schuh 1986: fig 12).

Figures

Figure 1. Habitus of Dariella rubrocuneata and Labriella fusca.

Figure 3. SEM images. Dariella rubrocuneata A head and pronotum, lateral view B head and pronotum, dorsal view C head, anterior view D labium E antenna F pleura G legs H trichobothria on hind femur I trichobothria on middle femur J hind tarsus K pretarsus, ventral view L cuneus and membrane cell M scutellum, clavus and corium.

Figure 4. Male genitalia. Dariella rubrocuneata A aedeagus, dorsal view B aedeagus, left lateral view C genital capsule, dorsal view D left paramere, dorsal view E left paramere, posterior view F right paramere, dorsal view G right paramere, posterior view.