Ambrysus sitesi Reynoso

Reynoso-Velasco, Daniel & Sites, Robert W., 2025, Revision of the Ambrysus signoreti Stål species complex (Heteroptera: Naucoridae: Ambrysinae). Section 3., Zootaxa 5735 (1), pp. 1-66 : 56-59

Ambrysus sitesi Reynoso

( Figs. 35–36 )

Ambrysus sitesi Reynoso in Reynoso-Velasco & Sites 2019a: Zootaxa 4615: 298–302 (original description).

Diagnosis. This species can be easily distinguished from other species in this section by the asymmetrical female SGP with a broad and evenly rounded lateral lobe at mid-length on the left margin. Additionally, the posterolateral corners are short and digitate and the central lobe appears truncate ( Fig. 35B ). Also, a distinctive feature of the males is the absence of the right endosomal sclerite of the phallosoma; only the left sclerite is present, which is convex and exhibits small rounded denticles along its margin ( Fig. 35E ).

Comparative notes. Only A. scalenus exhibits a similar left-lobed margin of the female SGP; however, the lobe extends further laterally and is truncate. The absence of the right endosomal sclerite in the male phallosoma is also a characteristic of A. lundbladi (Section 2); nevertheless, the existing left sclerite is smaller and inconspicuous in the latter species.

Discussion. This recently described species measures 9.80–11.60 in length and 6.20–7.50 in width. In the original description, Reynoso-Velasco & Sites (2019a) suggested a possible close relationship of A. sitesi and A. lundbladi based on the similar morphology of the endosomal sclerites exhibited by males of both species. This relationship was not supported in the molecular study by Sites (2022); instead, A. sitesi was sister to A. signoreti , while A. lundbladi was sister to A. inflatus in a different clade. Although a previous work ( Reynoso-Velasco & Sites 2021) also found the sister relationship of A. sitesi and A. signoreti , the study did not include A. lundbladi .

In his work on the Ambrysus of Mexico, La Rivers (1953a) described the subspecies A. lunatus menoides (currently a synonym of A. lundbladi Usinger ) from the states of Puebla and Chiapas. The type specimens of A. lunatus menoides from Chiapas were reported to be deposited only in the UMMZ. This collection has two males in total, which were examined and positively identified as belonging to A. sitesi . Additionally, the same case applies to a paratype-labeled female we found in the CAS. Since this collection was not reported as an original repository, we suspect this female specimen was donated to the CAS after the subspecies original description.

Variation. No variation was detected on the diagnostic features.

Type locality. Mexico: Oaxaca, Mpio. San Gabriel Mixtepec, Río Rana at San Gabriel Mixtepec , 16º06’06.3’’N, 97º03’52.9’’W, 712 m.

Repository. Female holotype ( Fig. 35A ) is housed at the IEXA.

Published records: GUATEMALA: Huehuetenango; MEXICO: Chiapas, Oaxaca ( Reynoso-Velasco & Sites 2019a).

Distribution. This species is distributed at elevations of 60–1200 meters in the southern Mexican states of Chiapas and Oaxaca and the western Guatemalan department of Huehuetenango ( Fig. 36 ). Most records from Oaxaca are in the Sierra Madre del Sur biogeographic province, while those from Chiapas and Huehuetenango are in the Chiapas Highlands province. A few records from the northern part of both states in Mexico are on the border with the Veracruzan province. Additionally, at least one record from the southern part of Chiapas is in the Pacific Lowlands province.

Type material examined. HOLOTYPE ♀. MEXICO: Oaxaca: Mpio. San Gabriel Mixtepec, km 194 carr. Puerto Escondido-Oaxaca, San Gabriel Mixtepec, Río Rana , 16º06’06.3’’N, 97º03’52.9’’W, 712 m, 03-Apr-2015, L-1906, Reynoso, Sites, Shepard & Barr colls . PARATYPES: same data as holotype ( 2♂, 2♀ CNIN; 10♂, 7♀ IEXA; 5♂, 4♀ UMC) ; Mpio. Jalapa de Díaz, Sto. Domingo, Río Sto. Domingo , 18°02’15.9’’N, 96°32’57.2’’W, 100 m, L-1881, 25-Mar-2015, Reynoso, Sites, Shepard & Barr colls. ( 2♂, 6♀ IEXA; 1♂, 1♀ UMC) ; Mpio. Putla Villa de Guerrero, Pluta de Guerrero, 17º02’21.5’’N, 97º54’42.9’’W, 767 m, 30-May-2012, L-1397, Reynoso-Velasco, D. coll. ( 1♂ UMC) ; Mpio. Sta. Maria Tecomavaca, carr. Tehuacán-San Francisco Telixtlahuaca, 16 km S of San Juan de los Cués , Río Salado , 17º55’50.5’’N, 97º00’04.2’’W, 544 m, 01-Jun-2012, L-1407, Reynoso-Velasco, D. coll. ( 1♂ UMC) . Chiapas: Mpio. Altamirano, Cuauhtemoc, Balneario Tzaconejá , Río Tzaconejá , 16°41’17.5’’N, 92°01’03.0’’W, 1172 m, 28-Mar-2015, L-1886, Reynoso, Sites, Shepard & Barr colls. ( 6♂, 3♀ IEXA; 4♂ UMC) ; Mpio. Amatengo de la Frontera, Barrio Sabinalito, Río Agua Caliente , 15°25’0.1’’N, 92°08’33.7’’W, 942 m, L-1898, 31-Mar-2015, Reynoso, Sites, Shepard & Barr colls. ( 4♂ IEXA) ; [Mpio. Ángel Albino Corzo], Finca Prusia, 10-V-85, M. Vértiz / Colección del Instituto de Biología , UNAM. México, D.F ( 1♂ CNIN) ; [Mpio. Ángel Albino Corzo], Finca Prusia, 12-V-85, F Arias / Colección del Instituto de Biología , UNAM. México, D.F ( 1♂, 2♀ CNIN) ; [Mpio. Ángel Albino Corzo], Finca Prusia, 12-V-85, H Velasco / Colección del Instituto de Biología , UNAM. México, D.F ( 3♂ CNIN) ; [Mpio. Ángel Albino Corzo], Finca Prusia, 12-V-85, M Vértiz / Colección del Instituto de Biología , UNAM. México, D.F ( 1♀ CNIN) ; Mpio. Ángel Albino Corzo, Río Prusia , 15º43’23.3’’N, 92º47’46.5’’W, 1010 m, 18-May-2012, L-1345, Reynoso-Velasco, D. coll. ( 1♂, 4♀ UMC) ; Mpio. Frontera Comalapa, El Caracol, 8 km S of Frontera Comalapa, Río Grijalva , 15°36’07.0’’N, 92°09’14.5’’W, 677 m, 31-Mar-2015, L-1897, Reynoso, Sites, Shepard & Barr colls. ( 1♂ IEXA) ; Mpio. Huixtla, Huixtla, Río Huixtla , 15°08’59.9’’N, 92°27’04.6’’W, 67 m, 31-Mar-2015, L-1899, Reynoso, Sites, Shepard & Barr colls. ( 1♂ IEXA) ; Mpio. Ixtapa, Ixtapa , 16º48’43.7’’N, 92º54’30’’W, 1030 m, 17-May-2012, L-1341, Reynoso-Velasco, D. coll. ( 6♂, 3♀ IEXA) ; [Mpio. Ixtapa], Ixtapa , #132, 27-IV-1941, I.J. Cantrall / Ambrysus lunatus menoides La Rivers PARATYPE / Ira La Rivers Collection Bequeathed to the California Academy of Sciences-1978 ( 1♀ CAS) ; Mpio. Ixtapa, Río Lajas at Pte. Río Lajas , 16º50’42.6’’N, 92º54’01.7’’W, 1020 m, 17-May-2012, L-1340, Reynoso-Velasco, D. coll. ( 2♂, 1♀ UMC) ; same but 28-Mar-2015, L-1885, Reynoso, Sites, Shepard & Barr colls. ( 10♂, 10♀ CNIN; 20♂, 21♀ IEXA; 6♂, 15♀ UMC) ; [ Mpio. Ixhuatán], 4 mi N of Tapiula [ Tapilula ], CL1097, 5 May 1964, JT & MS Polhemus ( 1♂, 1♀ USNM) ; [Mpio. Ocosingo], Ocosingo , June 25 1950, C. & M. Goodnight & L. Stannard, mountain stream / Chiapas, 25-VI-57, Mex. Stannard ( 1♂ SEMC) ; Mpio. Siltepec, km 72 carr. Jaltenango-Siltepec, nr. Nuevo Galeana , 15º35’54.9’’N, 92º32’28.9’’W, 933 m, L-1349, 19-May-2012, Reynoso-Velasco, D. coll. ( 2♂, 1♀ UMC) ; Mpio. Siltepec, km 92 carr. Jaltenango-Siltepec, Campo Aéreo , Río Bravo , 15º35’17.9’’N, 92º28’02.3’’W, 1068 m, 19-May-2012, L-1350, Reynoso-Velasco, D. coll. ( 1♂, 1♀ UMC) ; Mpio. Siltepec, Matasano, Río Matasano , 15º36’13.7’’N, 92º33’37.1’’W, 950 m, 19-May-2012, L-1348, Reynoso-Velasco, D. coll. ( 6♂, 6♀ IEXA; 16♂, 19♀ UMC) ; Mpio. Solosuchiapa, El Beneficio , Río La Sierra , 17°21’01.1’’N, 93°00’21.1’’W, 303 m, 27-Mar-2015, L-1884, Reynoso, Sites, Shepard & Barr colls. ( 1♂ UMC) ; Mpio. Solosuchiapa, Solosuchiapa, Río La Sierra , 17º25’40.5’’N, 93º01’35.7’’W, 122 m, 17-May-2012, L-1339, Reynoso-Velasco, D. coll. ( 1♂ UMC) ; [Mpio. Soyaló], Soyalo, Rio Blanco , CL1086, 4 May 1964, J. T. & M.S. Polhemus / C.J. Drake Accession ( 16♂, 10♀ USNM) ; Mpio. Tenejapa, ponds in stream above Habenal / 14.VII.1964, coll. D. Breedlove / C.J. Drake Accession / CAS ( 2♂ USNM) ; Rio Laja [s] nr Bochil, CL 668, 6-I-74, J. T. Polhemus ( 9♂, 5♀ USNM) ; Soyalo, Rio Lajas , CL1087, 4-May-1964, J. T. & M.S. Polhemus / A. guttatipennis close, No! / C.J. Drake Accession ( 1♀ USNM) . GUATEMALA: Huehuetenango: Rio Nentón , ca. 8 km NE of La Laguna, 10-May-2013, 15.79915º N, 91.88951ºW, 613 m, R. S. Zack coll. ( 1♀ WSUC) .

Additional material examined. MEXICO: Chiapas: [Mpio. Ixtapa], Ixtapa , #132, 27-IV-1941, I.J. Cantrall / Ambrysus lunatus menoides La Rivers PARATYPE ( 1♂ UMMZ); same but / Ambrysus lunatus menoides La Rivers determined by Ira La Rivers ‘50 ( 1♂ UMMZ) .

Figures

FIGURE 35. Structures of Ambrysus sitesi Reynoso. (A) Dorsal habitus of female holotype, (B) sternum VI and subgenital plate of female (terminal abdominal segments removed), (C) 6th and 7th abdominal terga of male, (D) 8th abdominal tergum of male, (E) ventral surface of male phallosoma.

FIGURE 36. Distribution of Ambrysus sitesi Reynoso.