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

Antrodiaetus effeminatus n. sp.

Figs. 1 , 7 , 13 , 26–27 , 36 , 42–43 , 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, N42°15’12”, W123°27’41” (518 m elevation), male holotype ( NMNH), 1 female paratype ( NMNH), 7 male paratypes (2, AMNH; 2 JCC; 1, 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. 53 ) 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. 51 ). 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. 51 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. 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. 53 ) 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/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. 13 ); male genital plate only faintly sclerotized, sclerotized areas divided ( Figs. 26–27 ).

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. 51 ) 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. 42–43 , 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. 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.

Figures

FIGURE 1. Map of Oregon showing study areas within the Siskiyou and Cascade Mountains and a list of mygalomorph species found in each area [relief map modified from: http: // www. flag. wr. usgs. gov / USGSFlag / Data / maps / Oregon. gif (accessed 31 August 2005)]. Insert shows position of region within the USA.

FIGURE 7. Abundance of adult male Antrodiaetus spiders collected in pitfall traps from southwestern Oregon.

FIGURES 12 – 15. Dorsal view of male body. 12, Antrodiaetus coylei n. sp.; 13, Antrodiaetus effeminatus n. sp.; 14, Antrodiaetus metapacificus n. sp.; 15, Antrodiaetus pacificus (Simon). Not to scale; see text for approximate sizes of the different species. Arrows indicate sclerotized patches.

FIGURES 22 – 33. Genital plates of males. 22 – 23, Antrodiaetus ashlandensis n. sp.; 24 – 25, Antrodiaetus coylei n. sp.; 26 – 27, Antrodiaetus effeminatus n. sp.; 28 – 29, Antrodiaetus metapacificus n. sp.; 30, Antrodiaetus montanus (Chamberlin & Ivie); 31, Antrodiaetus occultus Coyle; 32, Antrodiaetus pacificus (Simon); 33, Antrodiaetus pugnax (Chamberlin). Inserts emphasize sclerotized regions. Scale line = 0.5 mm.

FIGURES 34 – 37. Ectal view of male left chelicera. 34, Antrodiaetus ashlandensis n. sp.; 35, Antrodiaetus coylei n. sp.; 36, Antrodiaetus effeminatus n. sp.; 37, Antrodiaetus metapacificus n. sp. Scale lines = 0.5 mm.

FIGURES 42 – 45. Male left tibia I and metatarsus I. 42 – 43, Antrodiaetus effeminatus n. sp. (42, prolateral view; 43, ventral view). 44 – 45, Antrodiaetus metapacificus n. sp. (44, prolateral view; 45, ventral view). Scales = 0.5 mm in 0.1 mm divisions.

FIGURES 53 – 54. Dorsal view of seminal receptacles. 53, Antrodiaetus effeminatus n. sp.; 54, Antrodiaetus pacificus (Simon). Scales = 0.01 mm in 0.001 mm divisions.

FIGURES 49 – 52. Prolateral view of entire palp (left) and view of tip after palp rotated 90 ° on longitudinal axis of distal half of inner conductor sclerite. 49, Antrodiaetus ashlandensis n. sp.; 50, Antrodiaetus coylei n. sp.; 51, Antrodiaetus effeminatus n. sp.; 52, metapacificus n. sp. Scale lines = 0.1 mm.