Aphonopelma moderatum (Chamberlin & Ivie, 1939)

Hamilton, Chris A., Hendrixson, Brent E. & Bond, Jason E., 2016, Taxonomic revision of the tarantula genus Aphonopelma Pocock, 1901 (Araneae, Mygalomorphae, Theraphosidae) within the United States, ZooKeys 560, pp. 1-340 : 176-183

Taxon classification Animalia Araneae Theraphosidae

Aphonopelma moderatum (Chamberlin & Ivie, 1939) Figures 93, 94, 95, 96, 97; Suppl. material 4

Delopelma moderatum Chamberlin & Ivie, 1939: 9; male holotype from 5 miles E of Rio Grande City, Starr Co., Texas, 26.342436 -98.728749 5, elev. 231ft., 1.v.1937, coll. S. Mulaik; deposited in AMNH. Paratype male from 32 miles SW of Laredo, Webb Co., Texas, 27.305342 -100.013223 7, elev. 636ft., 10.iv.1936, coll. S. Mulaik; deposited in AMNH. [examined]

Rhechostica moderatum Raven, 1985: 149.

Aphonopelma moderatum Smith, 1995: 122.

Aphonopelma heterops Chamberlin, 1940: 29; female syntypes from Edinburg, Hidalgo, Co., Texas, 26.30173 -98.16335 5, elev. 96ft., ix-xii.1933, coll. S. Mulaik; deposited in the AMNH. [examined] syn. n.

Diagnosis.

Aphonopelma moderatum (Fig. 93) is a member of the moderatum species group can be identified by a combination of morphological, molecular, and geographic characteristics. Nuclear DNA identifies Aphonopelma moderatum as a phylogenetically distinct monophyletic lineage (Fig. 8), supported as the sister lineage to Aphonopelma gabeli and Aphonopelma moellendorfi sp. n. Females and subadult males are morphologically unique and can be readily identified by possessing an orange body disrupted by distinctly darkened (black or dark brown) banding on the patellae, metatarsi, and tarsi (Fig. 93). Aphonopelma moderatum can be distinguished from Aphonopelma anax by the shapes of its spermathecae and palpal bulbs; from Aphonopelma armada by lacking flared metatarsal scopulae and the unique pattern of setae on coxa I; and from Aphonopelma gabeli and Aphonopelma hentzi by phenotypic appearance. The most important measurement that distinguishes male Aphonopelma moderatum from its closely related phylogenetic and syntopic species is the article M1. Male Aphonopelma moderatum can be distinguished by possessing a larger M1/M4 (≥0.76; 0.76-0.81) than Aphonopelma armada (≤0.73; 0.63-0.73), Aphonopelma gabeli (≤0.74; 0.70-0.74), and Aphonopelma hentzi (≤0.75; 0.67-0.75); by possessing a smaller CL/M1 (≤1.30; 1.13-1.30) than Aphonopelma anax (≥1.36; 1.36-1.63) and Aphonopelma armada (≥1.36; 1.36-1.47); and a smaller PTl/M1 (≤0.69; 0.61-0.69) than Aphonopelma armada (≥0.73; 0.73-0.83) and Aphonopelma hentzi (≥0.74; 0.74-0.88). There are no significant measurements that separate male Aphonopelma moderatum from Aphonopelma moellendorfi . Significant measurements that distinguish female Aphonopelma moderatum from its closely related phylogenetic and syntopic species are Cl and T3. Female Aphonopelma moderatum can be distinguished by possessing a smaller Cl/A3 (≤2.46; 2.36-2.46) than Aphonopelma armada (≥2.48; 2.48-2.64); a smaller T3/T4 (≤0.70; 0.63-0.70) than Aphonopelma gabeli (≥0.73; 0.73-0.79); and a smaller P1/T3 (≤13.12; 8.14-13.12) than Aphonopelma anax (≥13.88; 13.88-19.15). There are no significant measurements that separate female Aphonopelma moderatum from Aphonopelma hentzi . Females of Aphonopelma moellendorfi are unknown and cannot be compared.

Description.

Male originally described by Chamberlin and Ivie (1939).

Redescription of male exemplar

(APH_0890; Fig. 94). Specimen preparation and condition: Specimen collected live from burrow, kept alive until mature, preserved in 80 % ethanol; deposited in AUMNH; original coloration faded due to preservation. Left legs I, III, IV, and left pedipalp removed for measurements and photographs; stored in vial with specimen. Right leg III removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). General coloration: Generally black or faded to brown. Cephalothorax: Carapace 15.55 mm long, 13.92 mm wide; densely clothed with black/brown iridescent pubescence appressed to surface; fringe covered in long setae not closely appressed to surface; foveal groove medium deep and straight; pars cephalica region rises gradually from foveal groove, gently arching anteriorly toward ocular area; AER slightly procurved, PER slightly recurved; normal sized chelicerae; clypeus extends forward on a curve; LBl 1.93, LBw 2.31; sternum hirsute, clothed with short length black, densely packed setae. Abdomen: Densely clothed in short black/brown pubescence with numerous longer, lighter setae interspersed (generally red or orange in situ); possessing a dense dorsal patch of black Type I urticating bristles ( Cooke et al. 1972). Legs: Hirsute, particularly ventrally; densely clothed in a mix of short black/brown setae. Metatarsus I slightly curved. F1 16.48; F1w 3.33; P1 6.42; T1 13.45; M1 12.91; A1 7.57; F3 13.5; F3w 3.72; P3 5.52; T3 10.78; M3 12.89; A3 7.51; F4 15.26; F4w 3.45; P4 5.83; T4 13.53; M4 16.91; A4 8.18; femur III is normal - not noticeably swollen or wider than other legs. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 65.6%; leg IV (SC4) = 31.3%. Two ventral spinose setae on metatarsus III; seven ventral spinose setae on metatarsus IV; one spinose seta on the anterior margin of retrolateral tibia I. Coxa I: Prolateral surface a mix of fine, hair-like and tapered/thin tapered setae. Pedipalps: Hirsute; densely clothed in the same setal color as the other legs, with numerous longer ventral setae; one spinose seta at the apical, prolateral femur; one spinose seta on the prolateral patella; five spinose setae on the prolateral tibia; PTl 7.919, PTw 2.53. When extended, embolus tapers with a gentle curve to the retrolateral side near apex; embolus very slender, no keels; distinct dorsal groove where the bulb transitions to the embolus.

Variation (9).Cl 11.46-16.06 (14.409 ± 0.52), Cw 9.49-14.51 (12.722 ± 0.57), LBl 1.52-1.99 (1.811 ± 0.05), LBw 1.7-2.36 (2.019 ± 0.09), F1 12.35-17.39 (15.218 ± 0.51), F1w 2.66-3.84 (3.453 ± 0.12), P1 4.99-7.03 (6.133 ± 0.23), T1 10.23-14.28 (12.43 ± 0.43), M1 10.1-13.38 (11.754 ± 0.35), A1 6.29-7.76 (6.957 ± 0.18), L1 length 43.96-59.84 (52.491 ± 1.65), F3 10.11-13.82 (12.24 ± 0.43), F3w 2.88-4.21 (3.611 ± 0.14), P3 4.17-6.13 (5 ± 0.25), T3 7.62-10.88 (9.55 ± 0.41), M3 9.45-13.75 (11.829 ± 0.44), A3 5.36-7.51 (6.729 ± 0.24), L3 length 36.71-52.05 (45.348 ± 1.72), F4 11.54-16.23 (14.024 ± 0.47), F4w 2.67-3.84 (3.347 ± 0.14), P4 4.27-6.10 (5.234 ± 0.24), T4 9.97-13.53 (12.232 ± 0.38), M4 12.82-17.54 (15.129 ± 0.52), A4 6.62-8.18 (7.478 ± 0.21), L4 length 45.64-61.46 (54.098 ± 1.77), PTl 6.258-8.692 (7.7 ± 0.23), PTw 2.033-2.70 (2.441 ± 0.07), SC3 ratio 0.481-0.782 (0.646 ± 0.03), SC4 ratio 0.313-0.503 (0.411 ± 0.02), Coxa 1 setae = tapered/thin tapered, F3 condition = normal/slightly swollen.

Description of female exemplar

(APH_0532; Figs 95-96). Specimen preparation and condition: Specimen collected live from burrow, preserved in 80% ethanol; deposited in AUMNH; original coloration faded due to preservation. Left legs I, III, IV, and pedipalp removed for photographs and measurements; stored in vial with specimen. Right leg III removed for DNA and stored at -80°C in the AUMNH (Auburn, AL). Genital plate with spermathecae removed and cleared, stored in vial with specimen. General coloration: Mostly appearing orange/brown with a mix of medium and longer length setae covering body, with black banding on the coxa, patella and metatarsi, and black tarsi. Cephalothorax: Carapace 15.6 mm long, 13.01 mm wide; densely clothed with brown/orange pubescence closely appressed to surface; fringe densely covered in long setae; foveal groove medium deep and slightly procurved; pars cephalica region rises from thoracic furrow more steeply than male, gently arching anteriorly toward ocular area; AER slightly procurved, PER recurved; clypeus extends forward on a curve; LBl 1.98, LBw 2.37; sternum hirsute, clothed with short, black/brown setae. Abdomen: Densely clothed in short black pubescence and longer gold/orange setae; dense dorsal patch of black Type I urticating bristles ( Cooke et al. 1972); ventral transition to black setae. Spermathecae: Paired and separate, quickly tapering to capitate bulbs, with wide bases that are fused. Legs: Hirsute, particularly ventrally; densely clothed in a mix of yellow/orange pubescence with numerous longer setae, and black setae forming bands (either complete or incomplete) around the patella, metatarsus, and tarsus. Coxa I: Prolateral surface a mix of fine, hair-like and tapered/thin tapered setae. F1 13.14; F1w 3.86; P1 5.74; T1 10.17; M1 8.26; A1 6.13; F3 10.15; F3w 3.62; P3 5.45; T3 7.38; M3 8.57; A3 6.41; F4 12.66; F4w 3.64; P4 5.6; T4 10.42; M4 11.91; A4 6.69. All tarsi fully scopulate. Extent of metatarsal scopulation: leg III (SC3) = 70.1%; leg IV (SC4) = 42.9%. One ventral spinose seta on metatarsus III; four ventral spinose setae on metatarsus IV. Pedipalps: Densely clothed in the same setal color and patterns as the other legs; one spinose seta on the apical, prolateral femur, one spinose seta on the prolateral patella, and five spinose setae on the prolateral tibia.

Variation (9).Cl 9.98-15.62 (12.719 ± 0.67), Cw 8.33-13.47 (10.64 ± 0.61), LBl 1.37-2.23 (1.701 ± 0.1), LBw 1.53-2.37 (1.914 ± 0.1), F1 7.936-13.14 (10.457 ± 0.6), F1w 2.497-3.98 (3.17 ± 0.17), P1 3.662-6.09 (4.812 ± 0.28), T1 6.485-10.17 (8.135 ± 0.4), M1 4.719-8.26 (6.4 ± 0.4), A1 3.974-6.27 (5.317 ± 0.25), L1 length 26.776-43.44 (35.122 ± 1.9), F3 5.974-10.15 (8.053 ± 0.51), F3w 2.164-3.62 (2.766 ± 0.19), P3 2.982-5.45 (3.686 ± 0.33), T3 4.486-7.38 (5.541 ± 0.35), M3 5.15-8.57 (6.447 ± 0.45), A3 4.086-6.41 (5.171 ± 0.32), L3 length 22.678-37.96 (28.898 ± 1.92), F4 7.761-12.66 (10.041 ± 0.54), F4w 2.287-3.66 (2.976 ± 0.16), P4 3.37-5.76 (4.291 ± 0.29), T4 6.417-10.42 (8.373 ± 0.43), M4 7.353-11.91 (9.486 ± 0.52), A4 4.808-6.91 (5.836 ± 0.26), L4 length 29.709-47.28 (38.028 ± 2.01), SC3 ratio 0.657-0.736 (0.699 ± 0.01), SC4 ratio 0.334-0.486 (0.413 ± 0.02), Coxa 1 setae = tapered/thin tapered. Spermathecae variation can be seen in Figure 96.

Material examined.

United States: Texas: Dimmit: Picnic area 3 miles NW Catarina on US-83, 28.375443 -99.64811 1, 566ft., [APH_0471-0472, 11/4/2009, 2 juv, Brent E. Hendrixson, AUMNH]; Hidalgo: Edinberg, 26.290053 -98.155073 5, 92ft., [APH_2208, 12/1937, 1♀, S. Mulaik, AMNH]; Jim Hogg: 1.4 miles W FM-649 on TX-16, 27.087044 -98.946036 1, 594ft., [APH_1132, 16/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Kinney: 0.59 miles E US-277 on FM-693, 29.17044 -100.673259 1, 972ft., [APH_1163, 17/3/2010, 1 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 4.6 miles SW US-90 on FM-1572, 29.21789 -100.260058 1, 1002ft., [APH_1157-1160, 17/3/2010, 4 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 7.8 miles W Hwy-131 on Hwy-90 (W of Brackettville), 29.33578 -100.53469 2, 1075ft., [APH_1448, 28/1/2012, 1 juv, Stanley A. Schultz, AUMNH]; Picnic area, 7.9 miles W FM-1572 on US-90, 29.280556 -100.323946 1, 1074ft., [APH_0474-0475, 11/4/2009, 2 juv, Brent E. Hendrixson, AUMNH]; Maverick: 11.1 miles N Webb County Line on FM-1021, 28.303931 -100.219328 1, 775ft., [APH_1140-1142, 16/3/2010, 3 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 4.55 miles S Kinney County Line on FM-1908, 29.020109 -100.569423 1, 913ft., [APH_1161-1162, 17/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 4.6 miles ESE Eagle Pass (jct US-57) on US-277, 28.69567 -100.39303 1, 833ft., [APH_0054, 17/7/2006, 1♀, Brent E. Hendrixson, AUMNH]; [APH_0057, 17/7/2006, 1♀, Brent E. Hendrixson, AUMNH]; [APH_0149, 17/7/2006, 1♀, Brent E. Hendrixson, AUMNH]; 5.2 miles N FM-2644 on FM-1021, 28.572348 -100.347434 1, 751ft., [APH_1143-1146, 16/3/2010, 4 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 9.0 miles NE US-57 on FM-481, 28.928198 -100.262798 1, 787ft., [APH_1147-1148, 17/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; off dirt road near Hwy-277, 28.67713 -100.32325 2, 830ft., [APH_1452-1453, 24/1/2012, 2 juv, Stanley A. Schultz, AUMNH]; McMullen: 0.7 miles S FM-624 on TX-16, 28.123878 -98.59089 1, 389ft., [APH_1118-1121, 14/3/2010, 4 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Starr: 0.4 miles SW Ranch Rd on FM-755, 26.52287 -98.69055 1, 482ft., [APH_1276, 12/5/2011, 1 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 3.2 miles E FM-2360 on US-83, 26.289361 -98.593355 1, 177ft., [APH_0464-0465, 10/4/2009, 2 juv, Brent E. Hendrixson, AUMNH]; 4.1 miles N US-83 on FM-3167, 26.429482 -98.850094 1, 279ft., [APH_1126-1128, 15/3/2010, 3 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 5 miles east of Rio Grande City, 26.377617 -98.789218 5, 151ft., [APH_2649, 29/4/1939, 1 juv, D. Mulaik, AMNH]; Falcon Reservoir, 26.574767 -99.128433 5, 370ft., [APH_0890, 2006, 1♂, Dave Moellendorf, AUMNH]; Rio Grande City, 26.379787 -98.820305 5, 161ft., [APH_2321, 29/9/1939, 1♀, 4♂, S. Mulaik, AMNH]; Uvalde: 1.93 miles NE Zavala County Line on FM-481, 29.095431 -99.961871 1, 855ft., [APH_1153-1156, 17/3/2010, 4 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Uvalde, near Nueces River, 29.067017 -99.84935 5, 783ft., [APH_0930, 2006, 1♂, Dave Moellendorf, AUMNH]; Val Verde: 0.25 miles N Kinney County Line on Hwy-277, 29.25733 -100.75319 2, 897ft., [APH_1447, 26/1/2012, 1 juv, Stanley A. Schultz, AUMNH]; [APH_1456-1457, 26/1/2012, 2 juv, Stanley A. Schultz, AUMNH]; Amistad National Recreation Area, US-277 North Campground, 29.511963 -100.907314 1, 1135ft., [APH_1168-1170, 17/3/2010, 3 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Comstock, 29.685333 -101.170783 1, 1550ft., [APH_0891, 15/7/2008, 1♀, Chris A. Hamilton, AUMNH]; [APH_0893-0894, 15/7/2008, 1♂, 1♀, Chris A. Hamilton, AUMNH]; Comstock Cemetery, 29.685451 -101.170515 2, 1565ft., [APH_0535, 4/6/2009, 1♀, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; Del Rio - Hwy 90 W of Lake Amistad, 29.56805 -101.0745 5, 1293ft., [APH_0929, 2006, 1♂, Dave Moellendorf, AUMNH]; Del Rio - Lake Amistad, 29.561667 -101.03155 1, 1149ft., [APH_0892, 15/7/2008, 1♀, Chris A. Hamilton, AUMNH]; Del Rio - Lake Amistad, 29.4704 -100.952283 5, 1112ft., [APH_0877, 7/2008, 1♀, Chris A. Hamilton, AUMNH]; Del Rio, 0.3 miles N Hwy-90 on Hwy-377, 29.4315 -100.908 2, 1104ft., [APH_1445-1146, 31/1/2012, 2 juv, Stanley A. Schultz, AUMNH]; Lake Amistad Rec Area, Spur 406, 29.59828 -101.06573 1, 1380ft., [APH_1291, 15/5/2011, 1 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Lake Amistad Rec Area, Spur 454, 29.469723 -100.950532 1, 1127ft., [APH_0534, 4/6/2009, 1 juv, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH]; Lake Amistad Rec Area, US-277N campground, 29.51043 -100.90765 1, 1125ft., [APH_1292, 15/5/2011, 1♂, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Langtry, along road that leads to dump, 29.81062 -101.56441 1, 1325ft., [APH_1290, 15/5/2011, 1 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Seminole Canyon State Park, N of campground, 29.6962 -101.32285 1, 1400ft., [APH_1286-1287, 13/5/2011, 2 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; Webb: 0.64 miles E FM-2895 on US-59, 27.699808 -99.027114 1, 562ft., [APH_1122-1124, 14/3/2010, 3 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 1.45 miles W FM-3338 on FM-1472, 27.661125 -99.584458 1, 562ft., [APH_1133-1134, 16/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 10.15 miles SE Maverick County Line on Eagle Pass Rd, 28.100947 -99.993316 1, 615ft., [APH_1138-1139, 16/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; 3.6 miles NW I-35 on US-83, 27.80051 -99.46291 1, 760ft., [APH_1283-1284, 13/5/2011, 2 juv, Brent E. Hendrixson, Kate Hall, Austin Deskewies, Alexis Guice, AUMNH]; 4.3 miles E Loop-20 on US-59 at Los Tios Creek, 27.561599 -99.390339 1, 467ft., [APH_0467-0470, 11/4/2009, 4 juv, Brent E. Hendrixson, AUMNH]; 7.35 miles NW Mines Rd on FM-1472, 27.838017 -99.832079 1, 531ft., [APH_1135-1137, 16/3/2010, 3 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; Laredo, 27.530614 -99.480215 5, 453ft., [APH_2319, 10/3/1936, 1♂, S. Mulaik, AMNH]; near Jct. Hwy-83 and I-35, 27.75556 -99.43975 2, 711ft., [APH_1450-1451, 19/1/2012, 2 juv, Stanley A. Schultz, AUMNH]; roadside park, 5.7 miles E Loop-20 on Hwy-59, 27.5684 -99.36855 2, 549ft., [APH_1454-1455, 18/1/2012, 2 juv, Stanley A. Schultz, AUMNH]; Zapata: 12.3 miles N FM-3169 (San Ygnacio) on Hwy-83, 27.21819 -99.41825 2, 339ft., [APH_1449, 21/1/2012, 1 juv, Stanley A. Schultz, AUMNH]; 2.0 miles SE FM-3169 on US-83, 27.025086 -99.411585 1, 364ft., [APH_0466, 10/4/2009, 1 juv, Brent E. Hendrixson, AUMNH]; Falcon State Park, 26.59031 -99.15428 1, 306ft., [APH_0031, 15/3/2005, 1♂, Brent E. Hendrixson, AUMNH]; Zavala: 1.5 miles E Maverick County Line on FM-481, 29.054763 -100.087256 1, 809ft., [APH_1151-1152, 17/3/2010, 2 juv, Brent E. Hendrixson, Gerri Wilson, Thomas Martin, AUMNH]; just S of Rest Area near Nueces River, 29.070874 -99.842183 1, 844ft., [APH_0532-0533, 3/6/2009, 1♀, 1♂, Brent E. Hendrixson, Courtney Dugas, Sloan Click, AUMNH].

Distribution and natural history.

Aphonopelma moderatum is widely distributed in counties bordering the Rio Grande in Texas from Langtry (Val Verde County) to Edinburg (Hidalgo County) to more interior areas such as McMullen County (Figs 1I, 97). The species distribution model predicts suitable habitat for this species along the Rio Grande throughout northeastern Mexico in Coahuila, Nuevo Leon, and Tamaulipas (Fig. 97). Specimens collected by the authors were found at elevations from 50 to 475 meters in the Southern Texas Plains (particularly in Texas-Tamaulipas Thornscrub), Western Gulf Coast Plains, and Chihuahuan Deserts Level III Ecoregions. This species has been found in syntopy with Aphonopelma anax throughout much of its range and probably overlaps with Aphonopelma armada , Aphonopelma hentzi , and Aphonopelma moellendorfi in the extreme northwestern portion of its distribution near Amistad Reservoir in Val Verde County. Burrows are typical of that for North American tarantulas (i.e., circular and generally covered by a thin veil of silk) and specimens can be readily collected by pouring a small amount of water into their burrows. In areas with shallow soils (e.g., Chihuahuan Desert habitats west of Amistad Reservoir), these spiders have been found under large flat rocks. Adult males wander during the spring (March-June) and have been observed shortly before sunset and during overcast afternoons.

Conservation status.

The type specimens of Aphonopelma heterops (considered a synonym of Aphonopelma moderatum ) were collected from Edinburg (Hidalgo County) in 1933. In the 80+ years since their collection, much of the land in this section of the Lower Rio Grande Valley has been converted for agricultural use. It is no surprise then that we failed to find these spiders near Edinburg despite traveling to the area numerous times. Consequently, Aphonopelma moderatum may be extirpated from the Edinburg-McAllen-Mission Metropolitan area, but these spiders may have never been particularly abundant in these parts in the first place given that the location is near the easternmost portion of their range. These tarantulas are among the most attractive species in the United States (Fig. 93) and are highly sought after by collectors for the pet trade. There is no evidence, however, that collectors have had any discernable impact on the numbers of this species. Aphonopelma moderatum is the most frequently encountered tarantula species at roadside picnic areas and along highway shoulders from Amistad Reservoir (Val Verde County) to Falcon Reservoir (Starr County), a distance of nearly 400 kilometers. Much of this area is surrounded and protected by privately owned ranches so the species appears to be secure.

Remarks.

Aphonopelma moderatum exhibits considerable sexual dimorphism in coloration. Adult females and immature specimens of both sexes possess perhaps the most distinctive color pattern of any species in the United States (i.e., tan to orange body with distinctly darker leg patellae, metatarsi, and tarsi). Adult males, on the other hand, are often solid black or dark brown. We suspect that Chamberlin and Ivie (1939) and Chamberlin (1940) described Aphonopelma moderatum and Aphonopelma heterops , respectively, due to these incredible differences in coloration (i.e., the description of Aphonopelma moderatum was based on adult male material whereas the description of Aphonopelma heterops was based on female or immature material). Our examination of the types and our extensive fieldwork throughout South Texas demonstrate that these two species are indeed conspecific. As a consequence, we consider Aphonopelma heterops a junior synonym of Aphonopelma moderatum .

Mitochondrial DNA (CO1) identifies Aphonopelma moderatum as a polyphyletic species with two divergent lineages spread across the tree (Fig. 7); both lineages were previously identified as separate species, one of which was cryptic, by Hamilton et al. (2014). Results from the AE analysis demonstrate that CO1 is not effective at accurately delimiting species boundaries within this group due to deep mitochondrial divergence. Interestingly, the mtDNA genetic break between these two divergent lineages coincides with the area near Amistad Reservoir, at the convergence of the Tamaulipan Scrublands, Chihuahuan Desert, and Edwards Plateau. The apparent biogeographical shift between mtDNA lineages may be indicative of past Pleistocene fragmentation as proposed by Hamilton et al. (2011).

Other important ratios that distinguish males: Aphonopelma moderatum possess a larger L1/L4 (≥0.95; 0.95-0.99) than Aphonopelma gabeli (≤0.95; 0.90-0.95). For both males and females, certain morphometrics have potential to be useful but due to the amounts of variation, small number of specimens, and/or the small differences between species no others are claimed to be significant at this time (see Suppl. material 2). During evaluation of traditional PCA morphospace, males of Aphonopelma moderatum separate from Aphonopelma anax , Aphonopelma armada , and Aphonopelma hentzi along PC1~2, but do not separate in PCA morphological space from Aphonopelma gabeli or Aphonopelma moellendorfi . Females separate from Aphonopelma anax along PC1~2, but do not separate from Aphonopelma armada , Aphonopelma gabeli , or Aphonopelma hentzi . Interestingly, Aphonopelma moderatum males separate from Aphonopelma anax , Aphonopelma armada , and Aphonopelma hentzi in three-dimensional PCA morphospace (PC1~PC2~PC3), but do not separate from Aphonopelma gabeli and Aphonopelma moellendorfi . Aphonopelma moderatum females separate from Aphonopelma anax , but do not separate from Aphonopelma armada , Aphonopelma gabeli , and Aphonopelma hentzi . PC1, PC2, and PC3 explain ≥87% of the variation in male analyses and ≥96% of the variation in female analyses. It is important to note the tremendous variation in spermathecae shape that can be seen across moderatum populations (Fig. 96). Previous taxonomic work considered this variation enough to split and describe separate species; this is clearly not an effective character due to the large amounts of subtle variation that is possible.