Diguetia dialectica Chamberlin, 1924

Jimenez, Maria-Luisa, Cardiel, Carlos Palacios & Chamé-Vázquez, David, 2022, The spider genus Diguetia Simon, 1895 (Araneae: Diguetidae) in North America a new species, redescriptions, and comments on the distribution of the genus, Zootaxa 5205 (2), pp. 125-146 : 131-136

Diguetia dialectica Chamberlin, 1924 stat. reval.

Figs 30–66 , 109

Diguetia dialectica Chamberlin 1924: 591 .

Diguetia canities dialectica Gertsch 1958: 13 .

Type material. ♀ Holotype from MEXICO: Baja California Sur: Municipality of Loreto, Carmen Island [25.958138°N, 111.16146°W], 23.V.1921, leg. R. V. Chamberlin ( CAS 1375 ); [Carmen Island, Gulf of California, May 23, 1921 ( CAS Catalog #1375], EXAMINED.

Other material examined. MEXICO: Baja California: Espiritu Santo Island , 01.VI.1921, leg. J.C. Chamberlin, ♀ ( MCZ: IZ:70264) . Sierra San Nicolas [16.4166670°N, 93.78333°W], 01.VI.1921, leg. J.C. Chamberlin, ♂ ( MCZ: IZ:70268) . Baja California Sur: Municipality of La Paz, Los Planes, Sierra La Gata , Arroyo La Escondida (23.80253°N, 109.89894°W, 464m), low deciduous forest, 01.X.2018, leg. C. Palacios & M.L. Jiménez, 2♂ (CARCIB-Ar 04633), 2♀ (CARCIB-Ar 04638); 5♀ (CARCIB-Ar 04639), 5♀ (CARCIB-Ar 04642; El Mautal (23.80761°N, 109.88808°W, 521m), low deciduous forest, 9.XI.2017, leg. C. Palacios, A. Falcón & M.L. Jiménez, 2♀ (CARCIB-Ar 04635); Rancho Santa Martha (23.87983°N, 109.92878°W, 161m), sarcocaule shrub, 8.XI.2017, leg. C. Palacios, M.L. Jiménez & A. Falcón, 1♀ (CARCIB-Ar 04636); Cañón de La Gata (23.84689°N, 109.89144°W, 319m), low deciduous forest, 5.XI.2017, leg. C. Palacios, A. Falcón & M.L. Jiménez, 1♀ (CARCIB-Ar 04637), 2♀ (CARCIB-Ar 04641) 1♀ (CARCIB-Ar 04634); Carretera San Juan de la Costa (24.21958°N, 110.59133°W, 15m), sarcocaule shrub, 9.X.2017, leg. C. Palacios, 1♂ (CARCIB-Ar 04640); Municipality of Loreto , San Basilio, Rancho Dagoberto, Cerro-Arroyo (26.36003°N, 111.43208°W, 21m), xeric shrub, 6.XII.2019, leg. M.L. Jiménez & C. Palacios, 3♀ (CARCIB-Ar 04643); (26.35956°N, 111.43189°W), mangrove, 6.XII.2019, 4♀ (CARCIB-Ar 04644); Rancho Santa Ana (26.51614°N, 111.42417°W, 3m), 6.XII.2019, 1♀ (CARCIB-Ar 04645); Arroyo Mesa del Chato (26.33625°N, 111.45864°W, 110m), xeric shrub, 7.XII.2019, 1♀ (CARCIB-Ar 04646) .

Diagnosis. Diguetia dialectica stat. reval. resembles D. balandra sp. nov. and D. canities in having a middorsal band flanked by two scalloped white bands on the abdomen, but D. dialectica stat. reval. has the middle dorsal band lighter, and the posterior scalloped bands are thinner than in D. balandra sp. nov. and D. canities ( Figs 31, 35 , 59, 62 ). Moreover, the dorsal band is not flanked with darker bands as in D. canities . The leg formula (4123) and ring pattern of D. dialectica stat. reval. and D. canities are similar, but the submedian ring of the former is diffuse to indistinct, while the ring patterns of D. canities are well marked, and D. balandra sp. nov. lacks such ring on tibiae and has a different leg formula (4123). The embolus tip of D. dialectica stat. reval. is attenuated and slightly bent ( Figs 41 , 46 ) while the embolus tip of D. balandra sp. nov. and D. canities is not bent. Moreover, the bulb of D. dialectica stat. reval. and D. canities has a small bulge near the bulb prong ( Figs 42, 45 ; Gertsch, 1958, fig. 16), whereas the bulge of D. balandra sp. nov. is less pronounced. Furthermore, the median membranous sac of D. dialectica stat. reval. and D. balandra sp. nov. are slightly longer than wide ( Figs 10 , 39 ), but the sac of the latter is longer ( Fig. 39 ), while in D. canities the apical portion of the sac is subspherical ( Gertsch, 1958: figs 18–19). The male opisthosoma of D. dialectica stat. reval. sometimes has a subtle caudal extension ( Figs 31, 33 , 61–63 ), whereas in D. balandra sp. nov. and D. canities it is absent ( Figs 2, 4 ).

Description. Male (CARCIB-Ar 04633). Coloration: carapace dark yellow with sparse black setae, and with two bands of white setae, which run from the ocular area and converge at the inconspicuous fovea, eyes with black rings. Carapace margins, clypeus, and sides next to coxae with white setae (scales) ( Fig. 30 ). Endites yellow with sparse white setae and margins darker. Labium dark yellow and sternum dark brown, both with sparse white setae, and sternum with margins dark ( Fig. 32 ). Legs I–II dark yellow without rings, Fm II darker distally, and Pt II darker. Legs III–IV light yellow, Fm III–IV, Ti III–IV and Mt III–IV with a distal ring, Pt III–IV darker, Ti III–IV with a submedian diffuse ring (arrow in Fig. 54 ). Dorsum and sides of opisthosoma grey, covered with white setae, and sparse dark setae, dorsum with a longitudinal dark band, broadened posteriorly with a wavy margin and bordered with thin bands of white setae ( Fig. 31 ). Venter of opisthosoma dark grey with sparse white setae, epigastric area, and spinnerets darker ( Fig. 33 ). Habitus: carapace suboval, cephalic region narrower than thoracic. The stridulatory file of chelicerae occupies almost all lateral face. Promargin of chelicerae with a transparent lamina and one tooth; retromargin with two teeth. Labium, endites and sternum longer than wide. Ta and Mt without scopula. Ta I with capsulate tarsal organ and slit sensilla ( Fig. 50 ), paired claws pectinate with 10 teeth. Opisthosoma with a small caudal extension (arrow in Figs 31, 33 ). Palp: Fm with three ventrolateral stridulating pins, Ta with two finger-like processes, the prolateral one shorter ( Fig. 40 ), the suboval bulb narrows apically (0.9 long, 0.4 wide; Figs 42–45 , arrow pointing small bulge of bulb), with spoon-shaped embolus (0.46 long) with the tip bent and flattened ( Figs 41 , 46 ), and a straight tubular prong slightly wider at the tip ( Figs 40, 42–43, 45 ), almost half-length of embolus (0.20 long), small bulge near Bp (blue arrow in Figs 42–43, 45 ). Measurements: total length 4.7; carapace 2.3 long, 1.3 wide; clypeus height 0.2; chelicerae length 0.7. Eye sizes and interdistances: AME 0.12, ALE 0.14, PME 0.14; AME–ALE 0.1, AME–PME 0.18. Length of legs segments: I 14.2 (4.5, 0.9, 0.4, 3.2, 1.6), II 12.6 (3.8, 0.9, 3.3, 3.3, l.3), III 8.8 (3.0, 0.5, 2.2, 2.4, 0.7), IV 13.4 (4.3, 0.8, 3.4, 3.8, 1.1). Leg formula 1423.

Female (CARCIB-Ar 04634). Coloration as the male but prosoma slightly darker ( Figs 34–37 ) and the median ring on Ti III–IV indistinct ( Fig. 55 ); metatarsal lyriform organ with six slits ( Fig. 49 ). External genitalia: semicircle anterior sclerotization larger than posterior, which is a small strip ( Fig. 38 ). Internal genitalia: two anterior oval pore plates, a membranous median sac, which is as long as wide, lies dorsally to the wide uterus externus ( Figs 39 , 47–48 ). Measurements: total length 9.11; carapace 3.5 long, 2.4 wide; clypeus height 0.4; chelicerae length 0.8. Eye sizes and interdistances: AME 0.12, ALE 0.12, PME 0.14; AME–ALE 0.14, AME–PME 0.24. Length of legs segments: I 11.6 (3.7, 1.0, 3.0, 2.6, 1.3), II 10.0 (3.1, 0.9, 2.5, 2.5, l.0), III 7.6 (4.0, 0.8, 1.6, 1.9, 0.9), IV 11.1 (3.6, 0.9, 2.6, 3.1, 0.9).

Variation. Some males with lighter legs, and some females with median ring on Ti III–IV indistinct. Males (n=4) total length: 4.4–6.0; carapace 1.8–2.8 long, 1.0–2.0 wide; clypeus height 0.2–0.3; chelicerae length 0.6–0.7. Length of legs segments: I 9.9−15.2 (3.2–4.9, 0.5–1.0, 2.8–4.1, 2.4–3.5, 1.0–1.7), II 8.9−13.4 (2.8–4.2, 0.5–0.8, 2.3–3.6, 2.3–3.5, 1.0–1.3), III 6.4−9.4 (2.0 –3.1, 0.5–0.7, 1.4–2.0, 1.8–2.6, 0.7–1.0), IV 9.4−14.7 (3.0–4.6, 0.5–0.8, 2.3–3.8, 2.7–4.3, 0.9–1.2). Eye sizes and interdistances: AME 0.16, PME 0.16, PLE 0.9–0.13, AME–PLE 0.9–0.13, AME–PME 0.16–0.19. Females (n=10) total length 6.5–9.3; carapace 2.5–3.4 long, 1.5–2.3 wide; clypeus height 0.3–0.5; chelicerae length 0.8–1.0. Length of legs segments: I 10.4−12.7 (3.4–4.0, 0.9–1.1, 2.7–3.3, 2.4–3.0, 1.0– 1.3), II 9.4−10.5 (3.0–3.1, 1.0, 2.2–2.6, 2.2–2.6, 1.0–1.2); III 7.0−8.0 (2.3–2.9, 0.6–0.9, 1.4–1.6, 2.0, 0.5–0.8), IV 9.8−11.4 (3.3–3.4, 0.8–1.0, 2.3–3.0, 2.5–3.0, 0.9–1.0). AME 0.16, PME 0.16, ALE 0.13–0.16, AME–ALE 0.16, AME–PME 0.16–0.23.

Remarks. Diguetia dialectica stat. reval. was reduced to a subspecies of D. canities by Gertsch (1958: 13). Nevertheless, we studied photographs of the female holotype (CAS), which is in bad conditions, and examined the male and female specimens (MCZ) studied by Gertsch (1958: 13–14) and we concluded that Chamberlin (1924) was right and this species should be considered a separate and related species to D. canities . Therefore, we propose to elevate it to species rank as originally proposed by Chamberlin (1924: 591).

Distribution. MEXICO: Baja California, Baja California Sur, including Espiritu Santo Island and Carmen Island ( Gertsch 1958; see Fig. 109 ).

Natural history. Webs of D. dialectica stat. reval. are found between branches of “palo Brazil ” ( Haematoxylum brasiletto ), “palo Adán” ( Fouquieria diguetii ), “pitaya dulce” ( Stenocereus thurberi ), “cholla” ( Opuntia cholla ) and “mala mujer” ( Cnidoscolus angustides ) in low deciduous forest of Sierra La Gata ( Fig. 107 ), Baja California Sur. The web is typical of Diguetia ( Fig. 51 ) and is usually found at 0.50–1.60 m above ground (n=16), but some were found at 3.0 m above ground between branches of “palo Brazil ” (n=3). The web and retreat are similar to those built by D. balandra sp. nov. but are covered with dead leaves, small twigs, and dead prey such as ants, leafhoppers, grasshoppers, and moths ( Fig. 52 ). The retreats are 4.2–12.0 cm long and 0.57–0.91 cm wide at bottom (n=16). The lenticular egg sacs (1–13) are layered as the same way as D. balandra sp. nov. inside of the retreat and the female also rests during the day covering the entrance with its opisthosoma. We did not find a male’s web, but two of them were captured in the female webs. The white setae (scales) are more conspicuous in live specimens ( Fig. 53 ).

Figures

FIGURES 30–39. Diguetia dialectica stat. reval. 30, 31, male habitus, dorsal; 32, 33, same, ventral; 34, 35, female habitus, dorsal; 36, 37, same, ventral; 38, female genitalia, ventral; 39, same, dorsal. Scale bars 30–37: 0.50 mm; 38–39: 0.20 mm.

FIGURES 40–45. Diguetia dialectica stat. reval. 40, male palp (black arrow pointing stridulating pins), prolateral; 41, same, retrolateral; 42, same (blue arrow pointing bulged part of bulb), dorsal; 43, same, slightly off views “prolateral”; 44, same, slightly off views “retrolateral”; 45, cleared male palp (arrow pointing bulged part of bulb), dorsal. Scale bars 40–45: 0.20 mm.

FIGURES 46–55. Diguetia dialectica stat. reval. 46, male palp, dorso-lateral; 47, female genitalia, ventral; 48, detail of lateral pore plates, dorso-lateral; 49, female metatarsal lyriform organ; 50, tarsal organ and sensilla of male leg I, dorsal; 51, web in situ; 52, retreat in situ; 53, live female specimen; 54, male leg IV, prolateral; 55, female leg IV, prolateral. Scale bars 54–55: 0.50 mm.

FIGURES 56–66. Diguetia dialectica stat. reval., 56–58 female holotype, 59–66 specimens studied by Gertsch (1958: 13– 14). 56, 59, female habitus, dorsal; 57, 60, same, ventral; 58, 66, female genitalia, ventral (inset specimens labels); 61, male habitus, lateral; 62, same, dorsal; 63, same, ventral; 64, male palp, slightly off views “prolateral”; 65, same, slightly off views “retrolateral”. Scale bars 56–63, 66: 0.50 mm; 64–65: 0.20 mm. Note: Figs 56–58 (including label) by the California Academy of Sciences used under CC BY-NC-SA 4.0; 64–65 by Museum of Comparative Zoology, Harvard University.

FIGURES 109–110. Records of North American Diguetia species.

FIGURES 1–10. Diguetia balandra sp. nov. 1, 2, male habitus, dorsal; 3, 4, same, ventral; 5, 6, female habitus, dorsal; 7, 8, same, ventral; 9, female genitalia, ventral; 10, same, dorsal. Scale bars 1–8: 0.50 mm; 9–10: 0.20 mm.

FIGURES 103–108. 103–105. Diguetia imperiosa. 103, live female specimen; 104, live male specimen; 105 web in situ; 106–108. Diguetia habitats. 106, Habitat of D. balandra sp. nov. at Balandra Beach, Baja California Sur, Mexico; 107, Habitat of D. dialectica stat. reval. at Sierra La Gata, Baja California Sur, Mexico; 108, Habitat of D. dialectica stat. reval. and D. imperiosa at San Basilio, Baja California Sur, Mexico.