Ambrysus baeus Polhemus & Polhemus

Reynoso-Velasco, Daniel, Sites, Robert W. & Novelo-Gutiérrez, Rodolfo, 2016, The Ambrysus Stål (Heteroptera: Naucoridae: Cryphocricinae) of Mexico: Revision of the subgenus Syncollus La Rivers, Zootaxa 4126 (1) : -

Ambrysus baeus Polhemus & Polhemus

( Figs. 3–4 )

A. baeus Polhemus & Polhemus 1981 : Pan-Pac. Entomol. 57: 399–400 (original description).

Diagnosis. This species can be distinguished from other species in the subgenus based on the overall body size, shape and length of the male AGP, shape of the medial lobes of tergum VIII (pseudoparameres), and shape of the posterior margin of the female SGP. Specifically, the body length is ≤ 6.8 mm. The AGP is generally narrow at the base, curving abruptly to the right at a nearly 90 degree angle, and is slightly expanded distally ( Fig. 3 B). The pseudoparameres are short, symmetrical, subrectangular, with the posterior margin nearly straight, the posterolateral corners rounded, and with a pile of scattered fine setae ( Fig. 3 C). The parameres are rounded with a row of long setae emanating from the middle of the dorsal surface ( Fig. 3 D). The right ventral lobe of the endosoma is lightly sclerotized ( Fig. 3 E). The posterior margin of the SGP has a deep, rounded central concavity almost twice as wide as deep ( Fig. 3 F).

Discussion. This species was described from a series of specimens collected in western Mexico. The authors placed this species in the same subgenus (Syncollus) as A. circumcinctus and A. pygmaeus and indicated that it had a similar color pattern as that of the latter species, but was smaller when compared with both species ( Polhemus & Polhemus 1981). The original description listed the length of the holotype at 5.75 mm, but it failed to provide a size range for paratypes. The length of our specimens is 5.20–6.80 mm. This is the smallest known of all species of Ambrysus in Mexico. The ground color is brown with the head, prothorax, and lateral corners of the scutellum light brown. The hemelytra are medium brown and patterned with light brown on the anterior 2/3 of the embolia and a conspicuous light brown triangular mark at the base of the posterior margin of the corium. The exposed connexiva are concolorous light brown ( Fig. 3 A).

Variation. The color pattern on specimens distributed in southern and eastern Mexico is different from that of western populations. Specimens from western states (Oaxaca to Nayarit) posses the same color pattern reported in the type series. In general, specimens from southern and eastern Mexico (Chiapas, northern Oaxaca, San Luis Potosí, Veracruz) present a darker color pattern on the prothorax, with the hemelytra dark brown and a small, inconspicuous light brown triangular mark at the base of the posterior margin of the corium. Also, the exposed connexiva present an alternating brown and light brown checkered appearance. A single population from Michoacán (Mpio. Apatzingán) in the west presented a similar color pattern to that described from eastern populations.

Structure of the AGP is variable; some specimens have a wider base and some have the posterior margin produced posteriorly, giving the impression of less abrupt curvature. Males from eastern Mexico generally present pseudoparameres with posterolateral corners that are more gradually angled as in A. chiapanecus n. sp. The SGP presents considerable variation in the shape and depth of the posterior margin. Some specimens from Jalisco presented an inverted V-shaped concavity, whereas others from Oaxaca presented a shallow concavity. The posterolateral corners of the SGP are narrow and pointed in the allotype, but we have observed variation from that of the allotype to wide and rounded posterolateral corners.

Type locality. Mexico: Nayarit: Mpio. San Blas, Aticama.

Repository. Holotype is housed at USNM.

Distribution. This species has been reported from Belize and three western states in the Mexican Pacific Coast biogeographic province. Based on our collections, A. baeus has a characteristic distribution pattern that includes the tropical lowlands of the Mexican Pacific Coast (Chiapas, Colima, Jalisco, Michoacán, Nayarit, southern Oaxaca) and the Mexican Gulf (northern Oaxaca, San Luis Potosí, Veracruz) biogeographic provinces. Although we neither collected this species nor found museum specimens that were collected in the state of Guerrero, it is probably present in the coastal and the Balsas Basin regions of Guerrero. We collected A. baeus and A. circumcinctus syntopically at L-1342, L-1371, L-1488, L-1661, L-1801, L-1802, L-1891, and L-1900.

Published records. Belize: Cayo ( Sites & Shepard 2015). Mexico: Colima, Jalisco, Nayarit ( Polhemus & Polhemus 1981).

Type material examined. HOLOTYPE ♂: Mex[ico]: Nay[arit]: [Mpio. San Blas], 5' Aticama, CL727A, VI- 7-1975, J. T. Polhemus / HOLOTYPE Ambrysus baeus J. T. Polhemus [&] D. A. Polhemus. PARATYPES: 5' Aticama, CL727A, VI-7-1975, J. T. Polhemus / PARATYPE Ambrysus baeus J.T. Polhemus & D. A. Polhemus (4³, 3♀ CAS; 1♀ CNIN; 1³, 1♀ EMEC; 2³, 2♀ USNM).

Material examined. MÉXICO: CHIAPAS: Mpio. Benemérito de las Américas, Flor de Cacao, tributario del Río Salinas, 16° 09' 24.4'' N, 90° 29' 38'' W, 140 m, 30-Mar-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1891 (1³, 1♀ UMC); Mpio. Jiquipilas, Rancho Bonito, Pte. Rancho Bonito, 16° 22' 06'' N, 93° 52' 04.2'' W, 689m, 03- Jun-2014, DRV & PRH colls., L-1814 (1³ UMC); Mpio. La Concordia, El Altillo, Río El Dorado, 16º 06' 27.5'' N, 92º 55' 29.3'' W, 524 m, 18-May-2012, DRV & PRH colls., L-1342 (1♀ UMC); [Mpio. Metapa], Metapa, Río Suchiate, 25-III-85, F. Arias (1³, 3♀ CNIN); same locality information but M. Vertiz (1♀ CNIN); same locality information but H. Velasco (3³, 2♀ CNIN); [Mpio. Tapachula], Tapachula, Río Huehuetan, 16-III-85, F. Arias (2♀ CNIN); Mpio. Villa Comaltitlán, Chapingo Dos, Pte. Vado Ancho, Río Vado Ancho, 15° 14' 51.8'' N, 92° 36' 02.2'' W, 57 m, 01-Apr-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1902 (1♀ UMC); Mpio. Villa Comaltitlán, Lázaro Cárdenas, km 238 carr. Huixtla-Mapastepec, 15º 10' 47.4'' N, 92º 32' 50.7'' W, 16 m, 20-May-2012, DRV & PRH colls., L-1353 (1♀ UMC); Mpio. Villa Comaltitlán, 1.36 km SE of Villa Comaltitlán, 15° 12' 45.8'' N, 92° 33' 46.1'' W, 48 m, 31-Mar-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1900 (1³ UMC); Mpio. Villa Corzo, Pte. El Carmen, nr. Revolución Mexicana, 16º 07' 51.4'' N, 93º 0.2' 00.9'' W, 547 m, 08-Jan-2012, DRV coll., L-1318 (1♀ UMC). COLIMA: [Mpio. Manzanillo], Pte. El Carrizo at Hwy. 98, 3 rd. km NE [SE] Camotlán, 7 Jan. 2005, C. B. Barr / 19° 13.00' N, 104° 14.66' W, elevation 1250 ft. (1♀ EMEC). JALISCO: Las Juntas Verano, 17 I 2005, Río Guapinole / William D. Shepard, leg. (3³, 1♀ EMEC); Mpio. Cabo Corrientes, Pte. Horcones, 20º 27.548' N, 105º 17.519' W, 330 m, 19-Mar-2014, J. A. Gómez, S. Smith, & R. Novelo colls. (11³, 5♀ UMC); Mpio. Tomatlán, Tomatlán, Río Tomatlán, 19° 56' 41.4'' N, 105° 14' 36.1'' W, 27 m, 25-Jun-2013, DRV & PRH colls., L- 1575 (8³, 6♀ UMC); Punta Hermanos, 5 I 2005, 980 ft, Río Horcones / William D. Shepard, leg. (1♀ EMEC); Río Cuitzmala, 2.5 km N of Emiliano Zapata, 6 Jan. 2005, C. B. Barr (4³, 2♀ EMEC); Río Guapinole, 1.3 rd. km E Las Adjuntas Verano-Las Adjuntas del Tuito, 17 Jan. 2005, C. B. Barr / 20° 28.67' N, 105° 16.45' W (1³ EMEC); Río Los Horcones, 1.1 rd. km W Las Juntas Verano/Las Juntas del Tuito, 5 Jan. 2005, C. B. Barr (3³, 2♀ EMEC); Río Purificación, 3.7 rd. km NW La Huerta, 8 Jan. 2005, C. B. Barr / 19° 29.50' N, 104° 39.63' W, elevation 740 ft. (1³, 1♀ EMEC); SE of Chamela, 6 I 2005, 180', Río Cuitzmala / William D. Shepard, leg (1³, EMEC); 4 km NW la Huerta, 8 I 2005, 740', Río Purificación / William D. Shepard, leg. (2♀ EMEC); 6.6 km SE Villa Purificación, 8 I 2005, Puente El Amborin / William D. Shepard, leg. (1♂, 2♀ EMEC). MICHOACÁN: Mpio. Apatzingán, California (arroyo), 21-Feb-2005, R. Novelo & Gómez-Anaya colls. (1³, 1♀ UMC); Mpio. Aquila, Aquila, Pte. Ramal Aquila, 18º 35' 08.1'' N, 103º 30' 51.8'' W, 159 m, 25-Dec-2012, DRV & PRH colls., L-1487 (2♂, 4♀ UMC); Mpio. Morelos, La Placita de Morelos, Pte. La Placita, Río Aquila, 18º 32' 19.9'' N, 103º 35' 17.9'' W, 7 m, 26-Dec-2012, DRV & PRH colls., L-1488 (1♂, 2♀ UMC). NAYARIT: Mpio. San Blas, El Palillo, Pte. Palillo, Arroyo Palillo, 21° 38' 27.1'' N, 105° 08' 30.8'' W, 43 m, 20-Dec-2013, DRV & PRH colls., L-1661 (2♂ UMC). OAXACA: Mpio. Ayotzintepec, San José Mano Márques, 17º 47' 26.2'' N, 96º 00' 15.3'' W, 66 m, 24-May-2012, DRV & PRH colls., L-1371 (1♀ UMC); Mpio. Candelaria Loxicha, Azulillo, Río Candelaria, 15º 53' 29.6'' N, 96º 29' 30.8'' W, 353 m, 26-May-2012, DRV & PRH colls., L-1377 (8³, 2♀ UMC); Mpio. Candelaria Loxicha, km 207 carr. Oaxaca-San Pedro Pochutla, Candelaria Loxicha, Río San Juan, 15º 55' 32.5'' N, 96º 29' 12.6'' W, 400 m, 25- May-2012, DRV & PRH colls., L-1375 (1³, 1♀ UMC); same but 02-Apr-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1904 (8³, 7♀ UMC); Mpio. Candelaria Loxicha, km 206 carr. Oaxaca-San Pedro Pochutla, Candelaria Loxicha, Pte. San Juan, 15º 55' 32.9'' N, 96º 29' 25'' W, 403 m, 26-May-2012, DRV & PRH colls., L-1376 (2♀ UMC); same but 02-Apr-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1905 (1³ UMC); Mpio. Mártires de Tacubaya, Mártires de Tacubaya, 16º 34' 41.1'' N, 98º 13' 08.7'' W, 206 m, 29-May-2012, DRV & PRH colls., L- 1390 (15³, 12♀ UMC); [Mpio. Pluma Hidalgo, El Pacífico] Finca El Pacífico, km 34 carr. Pochutla-Oaxaca, 8-III- 1995, 550 msnm, N 15 56 675, W 96 27 892, G. Ortega, E. Barrera (1♀ CNIN); Mpio. San Gabriel Mixtepec, km 194 carr. Puerto Escondido-Oaxaca, San Gabriel Mixtepec, Río Rana, 16º 06' 06.3'' N, 97º 03' 52.9'' W, 712 m, 27- May-2012, DRV & PRH colls., L-1380 (1³, 1♀ UMC); same but 03-Apr-2015, DRV, Sites, Shepard, Barr, & PRH colls., L-1906 (23³, 16♀ UMC); Mpio. San Pedro Huamelula, Morro Ayutla, Pte. Río Ayutla, Río Ayutla, 15° 54' 08.7'' N, 95° 51' 13.3'' W, 29m, 04-Jun-2014, DRV & PRH colls., L-1816 (1³, 1♀ UMC); km 179 carr. Sta. Maria Zacatepec-Putla, El Rosario, Pte. El Rosario, 16º 51' 34.6'' N, 97º 58' 44.7'' W, 361 m, 29-May-2012, DRV & PRH colls., L-1394 (4³, 3♀ UMC); km 201 carr. Mártires de Tacubaya-Santa Maria Zacatepec, ca. 13 km NE of San Pedro Amuzgos, 16º 42' 18.9'' N, 98º 00' 52.9'' W, 276 m, 29-May-2012, DRV & PRH colls., L-1391 (3♂, 2♀ UMC). SAN LUIS POTOSÍ: [Mpio. Huehuetlán], Huichihuayán, (Nacim. Río), 23-Jun-1990, R. Novelo col. (1♂ IEXA). VERACRUZ: [Mpio. Chicontepec], Chicontepec, 1-3-76, J. Bueno / Ambrysus baeus J. & D. Polhemus, det. J. Polhemus (1³ CNIN); Mpio. Paso de Ovejas, Paso de Ovejas, 19° 17' 04.1'' N, 96° 26' 03.7'' W, 40m, 29- May-2014, DRV & PRH colls., L-1802 (2♀ UMC); Mpio. Puente Nacional, Puente Nacional, Pte. Puente Nacional I, Río La Antigua, 19° 19' 28.5'' N, 96° 28' 54.3'' W, 67m, 29-May-2014, DRV & PRH colls., L-1801 (1♀ UMC); [Mpio. San Andrés Tuxtla, Los Tuxtlas], Salto [de] Eyipantla, 30-I-84, M. García / Fam: Naucoridae, Gen : Ambrysus Det. M. García (1♀ CNIN); same locality information but 01-Apr-2011, R. Novelo coll. (2³, 3♀ UMC); Mpio. San Rafael, El Faisán, 20° 11' 01.7'' N, 97° 05' 38.5'' W, 89 m, 12-Jun-2013, DRV, Sites, Shepard & PRH colls., L-1547 (1³, 1♀ UMC); Mpio. Tlapacoyan, ca. 4 km SW Vista Hermosa, 19º 56.891 N, 97º 0 7.893 W, 261 m, 8-Nov-2009, Sites, Cervantes & Novelo colls., L-1127 (1♀ UMC); [Mpio. Tlapacoyan ca. 4.5 km SW Vista Hermosa], waterfall at Rancho Nuevo, 19º 56.308' N, 97º 0 7.793 W, 270 m, 8-Nov-2009, Sites, Cervantes, & Novelo colls., L-1125 (1³, 1♀ UMC); Mpio. Tlapacoyan, Ixtacuaco (arroyo), 30-Mar-2003, R. Novelo col. (4♀ UMC); [Mpio. Tlapacoyan], Ixtacuaco, 07-Noviembre-2009, R. Novelo col. (2³, 1♀ IEXA); [Mpio. Tlapacoyan], Ixtacuaco, 6 IV 2011, 103 m, Río Ixtacuaco, N 20º 02', W 97º 07' / William D. Shepard leg. (1³, 3♀ UMC); [Mpio.] Tlapacoyan, 1 km antes El Cuajilote (ruinas Filobobos), 8-Nov-2009, R. Novelo col. (2³, 2♀ IEXA); 10 mi E Xalapa, Dec. 26, 1958, Menke & Stange / Ira La Rivers collection bequeathed to the California Academy of Sciences - 1978 (1♂ CAS).

Figures

FIGURE 3. Structures of Ambrysus baeus. (A) dorsal habitus of male, (B) 6 th and 7 th abdominal terga of male, (C) 8 th abdominal tergum of male, (D) genital capsule of male (phallosoma removed), (E) ventral side of phallosoma, (F) 6 th abdominal sternum and subgenital plate of female (terminal segments removed). agp = accessory genitalic process, pct = proctiger, pp = pseudoparamere, pr = paramere, pyg = pygophore, rvl = right ventral lobe, sgp = subgenital plate. Size bar = 0. 5 mm and applies only to Figs. D and E.

FIGURE 4. Distribution of Ambrysus baeus, A. chiapanecus n. sp., A. totonacus n. sp., A. pygmaeus, and A. xico n. sp. in Mexico (topographic map modified from Mexico map relief by Carport and used under CC BY 3.0).