Ambrysus schuhi Reynoso & Sites, 2019

Reynoso-Velasco, Daniel & Sites, Robert W., 2022, Revision of the Ambrysus signoreti Stål species complex (Heteroptera: Naucoridae Ambrysinae). Section 1., Zootaxa 5214 (3), pp. 421-439 : 433-435

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Ambrysus schuhi Reynoso & Sites


Ambrysus schuhi Reynoso & Sites

( Figs. 8–9 View FIGURE 8 View FIGURE 9 )

A. schuhi Reynoso-Velasco & Sites 2019a : Zootaxa 4615 (2): 294–297 (original description).

Diagnosis. This species can be distinguished from the other three in this section by the female SGP with a pointed apical lobe on the left margin and asymmetrical posterolateral corners; right corner subtriangular, left corner digitate ( Fig. 8B View FIGURE 8 ). Additionally, the male AGP tapers distally to a pointed and laterally directed apex ( Fig. 8C View FIGURE 8 ) and the pseudoparamere posterolateral corners are narrowly rounded ( Fig. 8D View FIGURE 8 ).

Comparative notes. At the time of its description, the female SGP of this species was considered similar to that of A. cosmius . Subsequent examination of specimens of A. variegatus has shown that the SGP of A. schuhi is more similar to that of the latter species. Notwithstanding, A. schuhi exhibits the SGP with the left apical lobe well-developed and subtriangular, posterolateral corners asymmetrical, and central lobe with a shallow concavity; whereas A. variegatus exhibits the apical lobe small and rounded, posterolateral corners symmetrical, and the central lobe with a prominent concavity. The overall dorsal appearance of A. schuhi is closer to that of A. variegatus than to A. cosmius .

Although at least three more species in the complex present apical lobes on the female SGP, one on each margin, A. schuhi is the sole species with a single and well-developed apical lobe on the left margin. The apical lobe exhibited by A. variegatus is inconspicuous.

Discussion. This recently described species measures 11.68–14.04 mm in length and 7.36–8.48 mm in width. In the original description, Reynoso-Velasco & Sites (2019a) suggested a close relationship of A. schuhi and A. cosmius based on the general morphology of the female SGP and the male endosomal sclerites exhibited by both species. This relationship was strongly supported in the recent molecular analysis of the group ( Reynoso-Velasco & Sites 2021). Unfortunately, that study did not include A. variegatus , which could be more closely related to A. schuhi than A. cosmius .

Variation. No variation was detected in the diagnostic features.

Type locality. Mexico: Oaxaca, Mpio. Sta María Zacatepec, El Rosario, 16º51'34.6''N, 97º58'44.7''W.

Repository. Female holotype ( Fig. 8A View FIGURE 8 ) is housed at the IEXA.

Published records: Mexico: Guerrero, Oaxaca ( Reynoso-Velasco & Sites 2019a).

Distribution. Ambrysus schuhi occurs in southern Mexico, in the states of Guerrero and Oaxaca ( Fig. 9 View FIGURE 9 ). The range includes localities below an elevation of 800 meters on the border of the Pacific Lowlands and Sierra Madre del Sur biogeographic provinces.

Type material examined. HOLOTYPE ♀ (by original designation). MEXICO: OAXACA: Mpio. Sta. Maria Zacatepec, km 179 carr. Sta. Maria Zacatepec-Putla, El Rosario , Pte. El Rosario, 29-May-2012, L-1394 / 361 m, 16º51'34.6''N, 97º58'44.7''W, Reynoso-Velasco coll. GoogleMaps PARATYPES: same data as holotype (3♂ IEXA; 6♂, 6♀ UMC); Mpio. Mesones Hidalgo, km 173 carr. Sta. Maria Zacatepec-Putla, Pte. La Junta, 29-May-2012, L-1395 / 396 m, 16º53'59.7''N 97º58'02''W, Reynoso-Velasco coll. (1♂ UMC); GoogleMaps Mpio. San Gabriel Mixtepec, Río Rana , km 194 carr. Puerto Escondido-Oaxaca, San Gabriel Mixtepec, L-1380 / 27-May- 2012, 712 m, 16º06'06.3''N 97º03'52.9''W, Reynoso-Velasco coll. (1♂, 1♀ UMC); GoogleMaps same but 3-Apr-2015, L-1906, Reynoso-Velasco, Sites, Shepard, & Barr colls., rocks & gravel (5♂, 1♀ IEXA; 3♂, 1♀ UMC); [ GoogleMaps Mpio. San Gabriel Mixtepec], San Gabriel Mixtepec, 20- V-84, M. García / Colección del Instituto de Biología , UNAM. México D.F. (1♂ CNIN; 1♂, 1♀ USNM); GoogleMaps Mpio. Sta. Maria Zacatepec, km 189 carr. Sta. Maria Zacatepec-Putla, S of El Tapanco, L-1393 / 29-May- 2012, 341 m, 16º47'28.3''N 97º59'20.4''W, Reynoso-Velasco coll. (2♂ UMC); GoogleMaps Mpio. Sta Maria Zacatepec, Km 201 carr. Mártires de Tacubaya-Santa Maria Zacatepec ca. 13 km NE of San Pedro Amuzgos, L-1391 / 29-May- 2012, 276 m, 16º42'18.9''N 98º00'52.9''W, Reynoso-Velasco coll. (1♂ UMC) GoogleMaps . GUERRERO: stream tributary to Laguna Tres Palos, about 22 miles from Acapulco on highway to Mexico City, III:22:1951 R.R. & M. Miller (2♂, 1♀ UMMZ) .


Coleccion Nacional de Insectos, Universidad Nacional Autonoma de Mexico


Smithsonian Institution, National Museum of Natural History


University of Michigan, Museum of Zoology














Ambrysus schuhi Reynoso & Sites

Reynoso-Velasco, Daniel & Sites, Robert W. 2022

A. schuhi

Reynoso-Velasco & Sites 2019
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