Antrodiaetus montanus (Chamberlin & Ivie)

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 : 29

Antrodiaetus montanus (Chamberlin & Ivie)

Figs. 3 , 21 , 30

Antrodiaetus montanus: Coyle 1971:359 –362, figs. 140, 150, 162, 171, 180, 213–217, 253–255, 295–298; Platnick 2005 (see for complete synonymy).

Material Examined. Washington: near Richland, Benton County, 2 males (JCC).

Diagnosis. The presence of setae on the upper ectal surface of the chelicera ( Fig. 21 ) will separate this species from all others in the genus except for A. hageni (Chamberlin) . From this latter species, the males differ by not having the metatarsus I swollen in the middle. In southwestern Oregon, it is the only member of the genus to have a procurved male genital plate ( Fig. 30 ).

Abbreviated Description. All three dorsal opisthosomal sclerotized patches separate; male genital plate with sclerotized parts undivided, thin, and procurved; chelicera without distodorsal projection, with setae on upper ectal surface; with prolateral brush of macrosetae on tibia I, 48–93% of macrosetae ensiform; tibia I with 6–23 (2–13 ensiform) macrosetae retrolaterally, without large heavy macrosetae ventrally; tibia and metatarsus I not swollen in lateral view; metatarsus I weakly sinuous, with one large retrolateral distal macroseta (seta A) ventrally; tip of palpal outer conductor sclerite not closely appressed to inner conductor sclerite; palpal tibia 2.54–2.78 times longer than wide; males active above ground in early August to early November.

Distribution. Great Basin region from Utah and Nevada north to Oregon, Idaho, and Washington ( Fig. 3 ; Coyle 1971: map 2).

Comments. The description is based upon data from Coyle (1971) as well as the examination of two males.

Figures

FIGURE 3. Map of southwestern Oregon (insert shows position of region within state) showing the distribution of Antrodiaetus occultus Coyle (triangles), Antrodiaetus montanus (Chamberlin & Ivie) (diamond), Atypoides gertschi Coyle (squares), and Hexura rothi Gertsch & Platnick (circles). Symbols from this study are closed whereas those recorded by Coyle (1971) and Gertsch & Platnick (1979) are open.

FIGURES 16 – 21. Characters of Mecicobothriidae and Antrodiaetidae. 16, Hexura rothi Gertsch & Platnick (male: 16, ventral view of spinnerets). 17 – 18, Atypoides gertschi Coyle (male: 17, dorsolateral view of chelicerae; 18, ventral view of spinnerets, arrow indicates third spinneret). 19 – 20, Antrodiaetus ashlandensis n. sp. (male: 19, dorsolateral view of chelicerae; 20, ventral view of spinnerets). 21, Antrodiaetus montanus (Chamberlin & Ivie) (male: dorsolateral view of chelicerae, insert shows dorsal view of chelicera with even coat of setae on middle portion). Not to scale.

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.