Delphiphylus, Pagola-Carte & Matocq, 2020

Pagola-Carte, Santiago & Matocq, Armand, 2020, A new genus to accommodate the misplaced Nearctic species Hoplomachus affiguratus (Uhler, 1895) (Heteroptera: Miridae: Phylinae), Zootaxa 4718 (2), pp. 269-276 : 270-272

Delphiphylus n. gen.

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Type species: Delphiphylus affiguratus ( Uhler, 1895) n. comb.

Material studied: 5 specimens: 2 ♂♂, 1 ♀, Colorado: Steamboat Springs , 16 july 1964, 7000’ H.H. Knight ; 1 ♂: Co Routt Co Yampa , 28-VII-1992, W.A. Jones. (coll. A. Matocq by exchange with Smithsonian Institution ( T. Henry )) ; 1 ♀, OR Umatilla CO. Lm N Kamela, 5 Jun 1979, Coll. Poman, AMNH _ IZC 00110670 (loaned from AMNH ( R. T. Schuh )) .

Diagnosis: Phylinae elongate and rather flat dorsally. Tegument shiny. Vestiture consisting of long, erect, black setae, arising from dark spots. Antennae robust but not incrassate. Calli of pronotum strongly marked, both structurally and chromatically, and delimited by dark spots. Mesothoracic spiracle and metasternal scent gland as in Fig. 3 . Hemelytral membrane greyish with whitish veins. Femora spotted. Tibial spines black, arising from dark spots. Claws ( Fig. 1 ) robust, strongly bent medially with the apical part nearly straight and the basal part conspicuously wide; pulvillus large but narrow, largely joined to the basal part of the claw. Male genitalia: pygophore ( Fig. 2 ) very long; right paramere ( Fig. 5 ) rectilinear, with a basal protuberance; left paramere ( Fig. 6 ) with sensory lobe short and blunt; vesica ( Fig. 7 ) “J”-shaped with lateral torsion, composed of two thick strands ending in two apical points forming a sub-right angle, with the secondary gonopore in subapical position. Female genitalia: dorsal wall of the genital chamber ( Fig. 8 ) sub-oval, with sclerotized rings sub-triangular and dorsal sac protruding dorso-posteriorly; vestibulum greatly developed, particularly to the right side ( Figs. 8–9 ); posterior wall present ( Fig. 10 ).

Etymology: the generic name Delphiphylus is formed by combination of Delphinium (generic name of the host plant) and Phylus (name of a genus of Phylinae abundantly used as a suffix in this subfamily). It is a masculine name.

Distribution: Nearctic, with a wide distribution in western USA and southwestern Canada.

Host plants: Ranunculaceae . In the only known species, genus Delphinium .

Discussion: Even though a shallow examination of the habitus reveals similarities between H. affiguratus and the other members of Hoplomachus such as the structure and patterns on head, scutellum and mesoscutum, as well as similarly dark and well-defined pronotal calli, a number of characters distinguish it. Needless to say, the obvious differences of colouration (in H. affiguratus both sexes are greenish brown to grey) are put aside, in a similar way as they are ignored concerning the Palaearctic members of the genus: H. flavopilosus (yellow-ochre-greenish), H. regina (orange-red) and H. thunbergi (grey-ochre-greenish).

Beyond the superficial appearance, the following distinguishing characters are considered as relevant: tegument shiny, setae arising from dark spots, segment II of antennae not incrassate in males, rostrum only reaching meso- coxae, tibial spines arising from dark spots, claws with basal part wide and pulvillus narrow ( Fig. 1 ), metathoracic scent-efferent system with a large and protruding auricle ( Fig. 3 ). More interestingly, the male and female genitalia are quite different in H. affiguratus ( Figs. 5–10 ) with respect to the Palaearctic Hoplomachus especies (see Matocq & Pagola-Carte 2008: figs. 4–8, 9–13, 14–18). At this point, we can assume that affiguratus does not belong in Hoplomachus .

The vesica is extensively used as a primary character to define the genera of Phylinae . Accordingly, in our search for a genus into which affiguratus could be accommodated, we checked the available information on this male genitalic structure. The whole literature available to us was thoroughly studied, with emphasis on Nearctic+Palaearctic+Holarctic Phylinae . Only a slight resemblance to the Holarctic Europiella Reuter, 1909 and Plagiognathus Fieber, 1858 , and the Palaearctic Amblytylus Fieber, 1858 and Placochilus Fieber, 1858 was noticed, each of these genera showing a disparate combination of characters which precludes further comparison.

Another approach consisted in a thorough study of the work by Schuh & Menard (2013), since it is the most comprehensive and recent classification of the Phylinae at a generic level. These authors place the Holarctic genus Hoplomachus in the subtribe Oncotylina (within the tribe Phylini ) because “the male genitalia and pretarsus in Hoplomachus are very similar to what is seen in Tinicephalus and the habitus is similar to some Plagiognathus spp.”, in spite of several characters of the external morphology that suggest placement in the subtribe Cremnorrhina (within the tribe Cremnorrhini). Being aware of the difficult task faced by these authors, we are obliged to be cau- tious in making no more than a little contribution to the tribal placement discussion. For instance, we partly agree with the above arguments for Hoplomachus , but only concerning the three Palaearctic species. The male genitalia of H. affiguratus has nothing to do with that of Tinicephalus . On the other hand, Hoplomachus is clearly separated by external morphology from the speciose genus Plagiognathus (see, for example, Schuh 2001: figs. 5–14). Concerning the recently erected genus Henryognathus Schuh & Salas, 2018 , it “falls within the diagnosis of Plagiognathus [...], with the exception of the structure of the male genitalia”, as stated by the authors ( Schuh & Salas 2018); again, its vesica is very dissimilar to that of H. affiguratus .

Among the vast diversity of phyline genera, we logically focused on tribes other than Hallodapini , Leucophoropterini and Pilophorini , devoting special attention to all explicit mentions to Hoplomachus throughout the text by Schuh & Menard (2013). The Palaearctic genus Opisthotaenia Reuter, 1901 is also classified within Oncotylina “because of the similarity of appearance with species of Phyllopidea [Knight, 1919] from the Nearctic, including similarity of structure of the endosoma, and its resemblance to Hoplomachus and Thermocoris [Puton, 1875] ( Seidenstücker 1968) in the Palearctic.” We verified that the male genitalia of H. affiguratus are completely different from those of Opisthotaenia and Thermocoris (see Wagner 1966, 1975, Seidenstucker 1968, Matocq 1985) and also different from those of Phyllopidea (see Schuh 2001: figs. 1c–d).

The western Nearctic species Hoplomachidea consors ( Uhler, 1893) was originally described in Hoplomachus . Reuter (1909) created the genus Hoplomachidea for it, highlighting the main differences, among them the conspicuous pale squamiform setae in H. consors . Schuh & Menard (2013) place the genus Hoplomachidea Reuter, 1909 in the subtribe Semiina (tribe Semiini), separating it from Hoplomachus and also from the subtribe Cremnorhina (tribe Cremnorhini), with which it shares several characters of external morphology and male genitalia. They conclude that “even though the name and some morphological attributes suggest an affinity with Hoplomachus , these two taxa are not members of the same clade with the Phylinae ”. Although we did not find any publication dealing with its genitalia, we also treat Hoplomachidea as a taxon clearly separated from both Palaearctic Hoplomachus and Nearctic H. affiguratus .

Thirdly, we also took into account the host plants of the phyline genera/species. As far as it is known (see Schuh 2002 – 2013), very few species develop on Ranunculaceae or even Ranunculales (including, among others, families Berberidaceae or Papaveraceae ). Except for Plagiognathus brevirostris Knight, 1923 (on Thalictrum spp. ( Schuh 2001)) and Plagiognathus luteus Knight, 1929 (on Berberis fremontii and B. haematocarpa ( Schuh 2001)) , the remaining ones are obviously not related with H. affiguratus . On the other hand, the Palaearctic members of Hoplomachus are found on Asteraceae . Concerning Hoplomachidea consors , it lives on Phacelia crenulata (Boraginaceae) .

Figures

FIGURES 3–4. Meso- and metapleura: 3. Delphiphylus n. gen. affiguratus (Uhler, 1895) n. comb., female; 4. Hoplomachus thunbergi (Fallén, 1807), female. (Only mesothoracic spiracle and metasternal scent-efferent system highlighted.)

FIGURES 1–2. Delphiphylus n. gen. affiguratus (Uhler, 1895) n. comb. 1. Metatarsal claw (Scale bar = 0.05 mm); 2. Pygo- phore, dorsal and lateral views. (Scale bar = 0.5 mm)

FIGURES 5–7. Delphiphylus n. gen. affiguratus (Uhler, 1895) n. comb., male genitalia. 5. Right paramere, different views; 6. Left paramere, lateral and (simplified) caudal views; 7. Vesica, two views. (Scale bar = 0.4 mm)

FIGURES 8–10. Delphiphylus n. gen. affiguratus (Uhler, 1895) n. comb., female genitalia. 8. Dorsal wall of the genital chamber; 9. Vestibulum (vulvar area), ventral view; 10. Posterior wall. (Scale bar = 0.4 mm)