Antrodiaetus effeminatus , Cokendolpher, James C., Peck, Robert W. & Niwa, Christine G., 2005

Cokendolpher, James C., Peck, Robert W. & Niwa, Christine G., 2005, Mygalomorph spiders from southwestern Oregon, USA, with descriptions of four new species, Zootaxa 1058, pp. 1-34: 21-26

publication ID

http://doi.org/ 10.5281/zenodo.170130

publication LSID

lsid:zoobank.org:pub:AFAA0F3F-B38B-4790-ACDB-6424429EA725

persistent identifier

http://treatment.plazi.org/id/F305878B-F757-FFE5-553E-FC32FE45FBA5

treatment provided by

Plazi

scientific name

Antrodiaetus effeminatus
status

n. sp.

Antrodiaetus effeminatus  n. sp.

Figs. 1View FIGURE 1, 7View FIGURE 7, 13View FIGURES 12 – 15, 26–27View FIGURES 22 – 33, 36View FIGURES 34 – 37, 42 –43View FIGURES 42 – 45, 46, 51, 53

Type Material. Oregon (collection on 9 Oct. 2001 by Niwa and Peck USFS): Josephine County, Ashland Resource Area, Medford District, Bureau of Land Management, N 42 ° 15 ’ 12 ”, W 123 ° 27 ’ 41 ” (518 m elevation), male holotype ( NMNHAbout NMNH), 1 female paratype ( NMNHAbout NMNH), 7 male paratypes (2, AMNHAbout AMNH; 2 JCC; 1, TTUAbout TTU; 2, WFIC).

Diagnosis. The absence of a distinct prolateral brush of macrosetae on male tibia I (Fig. 46, compare legs I and II) and the short and relative uniform width of stalks of the seminal receptacles ( Fig. 53View FIGURES 53 – 54) place this species in the Lincolnianus group used by Coyle (1971). Other members of this group are geographically distant in Arizona, New Mexico, and across the continental divide in Arkansas to Nebraska. Like, A. apachecus  from Arizona and New Mexico, the new species has the outer conductor sclerite tip moderately thick and erect ( Fig. 51View FIGURES 49 – 52). The new species is smaller than A. apachecus  (4.6–5.4 versus 3.4–4.5 prodorsal shield length in males). It also differs in the details of the distal tip of the outer conductor sclerite tip of the male (compare Fig. 51View FIGURES 49 – 52 with Coyle, 1971: figs. 230–232).

Etymology. The specific epithet refers to the feminine likeness of the males tibia I, which lacks a distinct brush of macrosetae.

Distribution. Known only from a single location within the Ashland Resource Area, Medford District, Bureau of Land Management, Josephine County, Oregon ( Fig. 1View FIGURE 1).

Description. Female (n = 1): body small, total body length 8.2, and slightly darker yellowish­brown than males, appendages and opisthosoma more evenly light brown with sclerotized patches on opisthosoma darker brown, dark brown pigment encircling anterior median eyes and between posterior median eyes and lateral eyes.

Dorsal shield of the prosoma 3.5 long, 2.65 wide, with setae scattered sparsely over pars thoracica except denser along lateral and posterior borders. Labrium with anterior two­thirds covered with longer setae, basal portion only with very short setae.

Opisthosoma 4.7 long, 3.4 wide; with two separate dorsal sclerotized patches. Bursa copulatrix ( Fig. 53View FIGURES 53 – 54) somewhat divided into two regions, but seminal receptacles not closely paired; stalks short and thick. Seminal receptacles with heavily sclerotized stalk of each receptaculum being relatively short and only slightly wider distally. Lateral lobes and bulbs slightly more slender than the medians; bowls weakly to not developed.

Leg I lengths: femur 2.7, tibia 1.65, metatarsus 1.5, tarsus 0.9. Leg IV lengths: femur 2.55, tibia 1.65, metatarsus 1.95, tarsus 1.05. Ratios (see Coyle, 1971): IVTL /IVTarL = 1.57, IVML / IMLAbout IML = 1.3.

Male (n = 8): body small, total body length 8.3 (6.7, 8.2), and straw to yellowishbrown, appendages and opisthosoma more evenly light brown with sclerotized patches on opisthosoma darker brown, dark brown pigment encircling anterior median eyes and between posterior median eyes and lateral eyes.

Dorsal shield of the prosoma 4.45 (3.4, 4.35) [mean ± s.d., 4.01 ± 0.34 (n = 8)] long, 3.2 (2.6, 3.2) wide, with setae scattered sparsely over pars thoracica except denser along lateral and posterior borders.

Opisthosoma 3.85 (3.3, 3.85) long, 2.7 (2.05, 2.7) wide; with three separate dorsal sclerotized patches ( Fig. 13View FIGURES 12 – 15); male genital plate only faintly sclerotized, sclerotized areas divided ( Figs. 26–27View FIGURES 22 – 33).

Chelicera with large area on upper ectal surface without setae; without distodorsal projection (36).

Palp with tibia swollen. Tibia 1.95–2.1 times longer than wide; widest in proximal third; 1.9 (1.7, 1.85) long, 0.9 (0.8, 0.95) wide. Tip of outer conductor sclerite ( Fig. 51View FIGURES 49 – 52) roundly pointed; not appressed to inner conductor sclerite, bent from it at tip. Tip of inner conductor sclerite well sclerotized and curved.

Leg I ( Figs. 42 –43View FIGURES 42 – 45, 46) without any segment being greatly enlarged or modified with processes; femur 3.8 (3.3, 3.8) long, patella 1.6 (1.45, 1.6) long, tibia 2.65 (2.3, 2.6) long, 0.6 (0.55, 0.7) wide, metatarsus 3 (2.65, 3.05) long, tarsus 1.95 (1.75, 2) long. Tibia I without dense group of prolateral macrosetae medially; macrosetae with 50–60 % being ensiform: with 12 (6 ensiform) [(10 (6 ensiform), 11 (6 ensiform)] macrosetae. Tibia I with 7 (7,7) medial macrosetae ventrolaterally, these extending to distal end, the longest seta about width of tibia (noticeably longer than any prolateral macrosetae). Tibia I without large heavy macrosetae ventrally; tibia and metatarsus I not swollen in lateral view; metatarsus I slightly sinuous to straight, with one retrolateral distal macroseta (seta A) ventrally; other setae ventrally on metatarsus I = 1.5 times greatest width of segment.

Wandering Activity. This species was only recorded on 9 October 2001 ( Fig. 7View FIGURE 7); four males were collected in the same pitfall trap with the single known female.

Comments. Antrodiaetus effeminatus  n. sp. was collected at a single site within the Douglas­fir/dry shrub plant association of the western Siskiyou Mountains. Douglas­fir dominated (> 60 % cover) the middle­ and overstory of this low elevation site (564 m), but California black oak ( Quercus kelloggii Newberry  ) (11 %), Pacific madrone ( Arbutus menziesii Pursh  ) (11 %) and tanoak ( Lithocarpus densiflorus (Hooker & Arnott)  (5 %) were also common. Overall, 35 plant species were identified on the site. The site sloped steeply (45 °) toward the east. Antrodiaetus effeminatus  n. sp. was the only mygalomorph spider collected at this site.

NMNH

Smithsonian Institution, National Museum of Natural History

AMNH

American Museum of Natural History

TTU

Texas Tech University, Museum

IML

Instituto Miguel Lillo