Canadian Journal of Arthropod Identification
 
 

Taxonomic revision of the Nearctic erosa species group of Phymata Latreille, 1802 (Heteroptera: Reduviidae: Phymatinae)

CJAI 41 -- October 1, 2020
doi:10.3752/cjai.2020.41

Paul Masonick & Christiane Weirauch

| Abstract | Introduction | Checklist | Materials & Methods | Species Key | Taxonomy | Acknowledgments | References | PDF | Cite |
| Appendix |
 
  Phymata obscura Kormilev, 1957 stat. nov.
    Figs 12A–E, 20J, 21J. Map 10.

Phymata americana obscura Kormilev, 1957
Kormilev, 1957: p136 (original description); Kormilev, 1962: p472 (revision); Henry and Froeschner, 1988: p602 (catalog); Froeschner and Kormilev, 1989: p45 (catalog)

Diagnosis: Recognized from other species of the Nearctic erosa group by the following combination of characters: (1) lateral notch of medium depth, (2) integument lacking elongated setaceous granulation, (3) absence of granulation patch between lateral pronotal notch and longitudinal carina of the posterior pronotal lobe, (4) transverse band on corium light in color, (5) brownish wing membrane, (6) dark markings along the anterior marginal corners of connexiva of abdominal segments 3–4, (7) rugose posterior pronotal disk, and (8) absence of prominent peaks or protuberances along the longitudinal carinae of the posterior pronotal lobe.

Redescription: Male: Medium to large, total length: ~7.57–8.88 mm, width across lateral angles of pronotum: ~2.90–3.66 mm. STRUCTURE: HEAD (Fig. 12A,D): distiflagellomere of male shorter than pedicel + basiflagellomere. THORAX (Figs 12A,D, 20J): thoracic surface matte; anterior pronotal disk without elongated setaceous granulation; posterior pronotal disk rugose; area between lateral pronotal notch and longitudinal carina of the posterior pronotal either with diffuse granulation or devoid of granulation; longitudinal carina without prominent tubercle; lateral margin of anterior pronotal lobe not keeled; lateral notch of medium depth; lateral margin of pronotum from lateral notch to lateral angle smooth or with light crenulation; lateral angle prominent and acute; posterior angle prominent and acute; lateral surface of forefemur smooth or sparsely granulated; lateral surface of thorax smooth or sparsely granulated; forewing membrane brown, cloudy, never hyaline. ABDOMEN (Fig. 12B): posterior corners of connexiva of abdominal segments 2–4 weakly serrate or dentiform; lateral margins of connexiva of abdominal segments 4–5 sinuous or straight; lateral margins of connexiva of abdominal segments 3–6 with or without fine granulation; connexivum of abdominal segment 5 less than twice as wide as connexivum of abdominal segment 4; connexivum of abdominal segment 6 rhomboidal, anterior and posterior margin roughly the same width. COLORATION (Figs 12A,B,D): variable; anterior pronotal lobe usually with dark marking; forefemur pale, never darkened; corium with a conspicuous transverse band. Female: Large, total length: ~9.52-10.31 mm, width across lateral angles of pronotum: ~3.31–4.16 mm. COLORATION (Figs 12A,B,C,E): with similar color patterns as males but usually lighter-colored overall.

Biology: Phymata obscura has been found on flowers of Asteraceae, Dipsacaceae, Lamiaceae, Rosaceae, and Scrophulariaceae. Specimens have been collected at elevations ranging between 168–1,681 m above sea level.

Distribution: Phymata obscura is restricted to the northern Great Basin and Palouse region.

Discussion: This species is often difficult to discern from P. metcalfi (which can also be found in Idaho and the northern Great Basin) and P. americana (which is found in southern Utah) and is most reliably identified using sequence data. Phymata obscura shares close relation to P. metcalfi and P. arctostaphylae (Masonick and Weirauch, 2020).

Identification remarks: These characters in particular help to distinguish P. obscura from P. americana and P. metcalfi: (1) rugose posterior pronotal disk (disk punctate in P. americana and P. metcalfi), (2) absence of prominent peaks or protuberances along the longitudinal carinae of the posterior pronotal lobe (present in western populations of P. americana), (3) connexivum of abdominal segment 5 not abruptly dilated in males (abdomen may appear dilated at connexivum of abdominal segment 5 in some western P. americana specimens), and (4) brownish wing membrane (usually hyaline in P. metcalfi).

Type information: Kormilev’s holotype was examined and is deposited in the United States National Museum of Natural History in Washington D.C.
HOLOTYPE: Phymata obscura Kormilev, 1957: Male: USA: Idaho: Moscow, 18 Aug 1940, T. A. Brindley,
(UCR_ENT 00008091) (USNM). Fig. 21J.

Additional material examined: See Appendix; 179 specimens, including 121 adult males and 58 adult females.