Ambrysus inecol 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 : 28-30

Ambrysus inecol Reynoso

( Figs. 15–16 )

Ambrysus inecol Reynoso in Reynoso-Velasco 2023: Zootaxa, 5271: 561–565 (original description).

Diagnosis. This species can be distinguished from others in the section by the almost symmetrical and tapering female SGP with right-angled lateral lobes at mid-length of each margin; the lobe on the right margin is only slightly smaller. Additionally, the posterolateral corners are short and pointed and the central lobe is poorly developed and shallowly concave medially, giving the appearance of two rounded lobes ( Fig. 15B ). Also, the male phallosoma presents the endosoma apically sclerotized on the left side ( Fig. 15E black arrow) and both endosomal sclerites knob-like with inconspicuous denticles ( Fig. 15E ).

Comparative notes. Ambrysus inecol is overall similar to A. magniceps ; nevertheless, females of A. inecol exhibit a characteristic SGP that tapers apically, the width of the posterior margin is approximately 1/3 of the SGP’s maximum width, which contrasts with the approximately 2/ 3 in A. magniceps . Also, the SGP central lobe of A. inecol is shallowly concave medially, giving the appearance of two rounded lobes at the same level or only slightly below the level of the posterolateral corners, whereas the central lobe in A. magniceps is evenly convex (without a medial concavity) and slightly beyond the level of the posterolateral corners. The digitate shape of the sclerotized male endosoma is also more similar to that of A. magniceps because the structure is lobe-shaped in A. altiplanus .

Discussion. This species measures 11.50–13.50 in length and 6.75–8.13 in width. The shapes of the male accessory process, pseudoparameres, and sclerotized endosoma of A. inecol are similar to those of A. altiplanus and A. magniceps , which we consider as evidence of a close relatedness.

The shape of the pseudoparameres and characteristics of the phallosoma in males, as well as a compact, oval, and particular convex body shape were features used to conceptualize A. magniceps (Reynoso-Velasco 2023) . This conception resulted in the overlooking of variation in the shape of the female SGP (informative attribute for species identification in the genus Ambrysus ), which was the basis to describe A. inecol .

Some specimens from western Mexico deposited in various collections (e.g., CAS, USNM) where identified by DRV as A. magniceps ; however, the concept of the species has changed after the description of A inecol . Consequently, further examination is necessary to clearly establish whether those specimens belong to A. magniceps or A. inecol . These specimens were not included in this study.

Variation. Some females presented the SGP with a central lobe only shallowly concave medially. Additionally, a female from Jalisco (Cabo Corrientes) and that from Michoacán exhibited the central lobe evenly rounded.

Type locality. Mexico: Nayarit: Mpio. Ahuacatlán, Río Tetitlán at Puerta del Río ( Balneario El Paraiso), 21°10’59.3’’N, 104°38’32.9’’W .

Repository. Female holotype ( Fig. 15A ) is housed at the IEXA.

Published records. MEXICO: Nayarit, Jalisco, Michoacán (Reynoso Velasco 2023) .

Distribution. Ambrysus inecol exhibits a neotropical distribution in west-central Mexico, in the states of Jalisco, Michoacán, and Nayarit ( Fig. 16 ). Most of the localities where the species has been recorded are on the border of the Pacific Lowlands and the westernmost and northwesternmost sections of the Transmexican Volcanic Belt ( Nayarit) and Sierra Madre del Sur ( Jalisco) biogeographic provinces, respectively. Only the record from Michoacán is on the border of the Balsas Basin and Transmexican Volcanic Belt biogeographic provinces. All the localities are at elevations below 1,000 meters.

Type material examined. HOLOTYPE ♀. MEXICO: Nayarit: Mpio. Ahuacatlán, Río Tetitlán at Puerta del Río ( Balneario El Paraiso ), 21°10’59.3’’N, 104°38’32.9’’W, 859 m, 18-XII-2013, L-1651, Reynoso-Velasco, D. coll. PARATYPES: same data as holotype ( 1♀ CNIN; 2♂, 3♀ IEXA; 1♂, 1♀ UMC) ; Mpio. Compostela, Río Compostela at Compostela , 21°14’01.4’’N, 104°53’38.6’’W, 853 m, 18-XII-2013, L-1652, Reynoso-Velasco, D. coll. ( 1♂, 1♀ IEXA) ; [Mpio. Compostela, Río El Refilión at] puente El Refilión on carr. Nayarit-Compostela , [ 21°18’19.9’’N, 104°54’29.1’’W, 790 m], 26-X-1989, A. Cadena coll. ( 1♀ CNIN) . Jalisco: Mpio. Cabo Corrientes, arroyo at puente Horcones , 20°27.548N, 105°17.519W, 330 m, 19-III-2014, J.A. Gómez, S. Smith & R. Novelo colls. ( 6♂, 2♀ IEXA) ; Mpio. San Sebastián del Oeste, arroyo at km 52+800 on carr. 544 Potrero de Arriba-Palmillas de Macedo , 481 m, 20°49.015N, 104°58.811W, 06-IX-2014, J.A. Gómez, S. Smith & R. Novelo colls. ( 1♀ IEXA) . Michoacán: Mpio. Buenavista, river at Buenavista Tomatlán , 19º12’57.8’’N, 102º34’30.2’’W, 440 m, 24-XII-2012, L-1481, Reynoso-Velasco, D. coll. ( 1♂, 1♀ IEXA) .

Figures

FIGURE 15. Structures of Ambrysus inecol Reynoso. (A) Dorsal habitus of female holotype, (B) sternum VI and subgenital plate of female (terminal abdominal segments removed; dashed line indicates plate’s mid-length), (C) 6th and 7th abdominal terga of male, (D) 8th abdominal tergum of male, (E) ventral surface of male phallosoma (black arrow indicates digitate portion of endosoma).

FIGURE 16. Distribution of Ambrysus inecol Reynoso.