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

Paul Masonick & Christiane Weirauch

| Abstract | Introduction | Checklist | Materials & Methods | Species Key | Taxonomy | Acknowledgments | References | PDF | Cite |
| Appendix |
  Phymata rossi Evans, 1931
    Figs 16A–E, 20N, 21M. Map 14.

Phymata rossi Evans, 1931
Evans, 1931: p270 (original description); Kormilev, 1962: p395 (revision); Henry and Froeschner, 1988: p604 (catalog); Froeschner and Kormilev, 1989: p58 (catalog)
Phymata granulosa texasana Kormilev, 1957 syn. nov.
Kormilev, 1957: p134 (original description); Henry and Froeschner, 1988: p603 (catalog); Froeschner and Kormilev, 1989: p53 (catalog)

Diagnosis: Recognized from other species of the Nearctic erosa group by the following combination of characters: (1) elongated setaceous granulation on the head and thorax, (2) crenulated margin of the pronotum and connexiva, and (3) sepia or rosette colored body, the lateral and ventral surfaces of which and the legs often with a pinkish blush.

Redescription: Male: Small to medium, total length ~6.59–8.0 mm, width across lateral angles of pronotum: ~2.61–3.18 mm. STRUCTURE: HEAD (Fig. 16A,D): distiflagellomere of male shorter than pedicel + basiflagellomere. THORAX (Figs 16A,D, 20N): thoracic surface matte; anterior pronotal disk with elongated setaceous granulation; posterior pronotal disk punctate; area between lateral pronotal notch and longitudinal carina of the posterior pronotal lobe with a distinct granulation patch; longitudinal carina with prominent tubercle bearing elongated granules; lateral margin of anterior pronotal lobe not keeled; lateral notch of medium depth; lateral margin of pronotum from lateral notch to lateral angle heavily crenulated with prominent tubercles; lateral angle prominent and acute; posterior angle prominent and acute; lateral surface of forefemur heavily granulated; lateral surface of thorax heavily granulated; forewing membrane brown, cloudy, never hyaline. ABDOMEN (Fig. 16B): posterior corners of connexiva of abdominal segments 2–4 weakly serrate or dentiform; lateral margins of connexiva of abdominal segments 4–5 sinuous; lateral margins of connexiva of abdominal segments 3–6 rough, crenulated / heavily granulated; 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 16A–D): variable; anterior pronotal lobe usually with dark marking; forefemur sepia to rosette in color, never black; corium with a conspicuous sepia to rosette transverse band. Female: Medium, total length: ~8.21–8.82 mm, width across lateral angles of pronotum: ~3.12–3.38 mm. COLORATION (Figs 16A,B,E):

Biology: Phymata rossi has been found on Asclepias L., Helianthus L., Sphaeralcea A. St.-Hil., Ligustrum L., Purshia DC. ex Poir., several genera of Fabaceae including Cassia L., Melilotus Mill., Mimosa L., and Prosopis L., and Quercus L (Fagaceae). Specimens have been collected at elevations ranging between 574–1,839 m above sea level.

Distribution: While the majority of P. rossi species examined were collected in Arizona, this species has also been found in California, New Mexico, Texas, and Utah.

Discussion: Phymata rossi, as well as P. granulosa and P. salicis, are the only erosa group taxa that have extensive elongated setaceous granulation on their head and thorax. Molecular evidence indicates that P. rossi is closely related to sympatric P. borica. Since the holotype of P. granulosa texasana Kormilev bears a lateral pronotal margin more like that of P. rossi than P. granulosa (e.g., has a very acute lateral angle that is directed posteriorly), lacks a darkly colored forefemur, and occurs closer to the documented distribution of P. rossi than P. granulosa, we here synonymize P. granulosa texasana Kormilev with the former. Some populations display differences in the degree of setaceous granulation covering the body.

Identification remarks: In the southwestern United States, P. saileri is the only other species of the erosa group that also bears conspicuous elongated setaceous granulation on the head and thorax. Phymata rossi is generally much lighter in color than P. saileri and lacks a glossy cuticle.

Type information: Evans’ holotype is deposited in the University of Kansas Biodiversity Institute, but only a paratype from the same collection was examined for this revision. Kormilev’s holotype of P. granulosa texasana was examined and is deposited in the United States National Museum of Natural History in Washington D.C.
HOLOTYPE: (Phymata rossi Evans, 1931): ♂, USA: Arizona: Cochise Co.: Huachuca Mountains, 08 Aug 1927, R.H. Beamer, (KU).
PARATYPE: (Phymata rossi Evans, 1931): USA: Arizona: Cochise Co.: Huachuca Mountains, 31.50200°N, 110.39940°W, 01 Aug 1927, R. H. Beamer, 1♀ (UCR_ENT 00070062) (KU).
HOLOTYPE: (Phymata granulosa texasana Kormilev, 1957): ♂, USA: Texas: Chisos Mountains, 09 Jul 1936, J.N. Knull, (UCR_ENT 00008097), (USNM). Fig. 21M.

Additional material examined: See Appendix; 106 specimens, including 62 adult males and 38 adult females.