Comprehensive Description

Read full entry

Erigone denticulata Chamberlin & Ivie

(Figs 7, 9, 17-23)

Erigone denticulata Chamberlin & Ivie 1939, 57, fig. 2; Levi & Levi 1951, 220; Levi & Levi 1955, 36; Buckle et al. 2001, 116; Platnick 2007.

Type material.- U.S.A. : Utah : Summit County:Mirror Lake, Uintah Mountains,N40°42'W110°49' , 22 Sept. 1932,W. Ivie,maleholotype (not examined). Mirror Lake,N40°43'W110°53' , 28 July 1936,Wilton Ivie,3 males labeled by Ivie as paratypes ( AMNH , examined).

Material examined.- U.S.A. : Colorado : Grand County:Hot Sulphur Springs,N40°6'W106°9' , 24 Aug. 1935,W. Ivie,1 male,1 female ( AMNH ). Idaho : Payette County:N.E. Fruitland,N44°1'W116°55' , 1 July 1938,W. Ivie,4 males,1 females ( AMNH ). Nevada : Elko County:Ruby Valley,N40°15'W115°25' , Sept. 1937,R.V. Chamberlin,4 males,3 females ( AMNH ). Oregon : Malheur County:8 km south of Adrian, N43°40'W117° , 19 Sept. 1943,W. Ivie,3 males,1 female ( AMNH ). Texas : Lubbock County,Lubbock , N33° 32'2"W101°53'23" , Sept. 2006,J.C. Cokendolpher, in wet greenhouse next to man-made pond, 1 female ( TTU-Z29,680 ); same locality & collector, on waterfall of man-made pond, 11 June 2007 ( AMNH ); Briscoe County:Playa Br5,N34°29'4.91999"W101°9'54.359" , 17 June 2005,S.M. Torrence,L.M. Smith,1 female ( AMNH ); Playa Br13,N34°32'12.336"W101°17'37.212" , 15 June 2005,S.M. Torrence,L.M. Smith,1 female ( CPAD ). Playa Br13,N34°32'12.336"W101°17'37.212" , 17 June 2005,S.M. Torrence,L.M. Smith,1 female ( TTU-Z29,683 ). Playa Br19,N34°28'19.01999"W101°15'32.616' , 22 June 2005,S.M. Torrence,L.M. Smith,1 male,1 female ( TTU-Z29,681 and 29,679 ); 26 June 2005,S.M. Torrence,L.M. Smith,1 female ( TTU-Z29,682 ). Swisher County:Playa S6,N34°32'37.644"W101°34'14.808" , 21 June 2005,S.M. Torrence,L.M. Smith,1 male ( CPAD ). Utah : Summit County:Mirror Lake, Uintah Mountains,N40°43'W110°53' , 22 Sept. 1932,W. Ivie,3 females ( AMNH ). Wyoming : Albany County:southeast of Laramie,N41°10'5"W 105°21'0",July 1961,W.D. Fronk,1 male,1 female ( AMNH ).

Diagnosis.-Male with marginal rows of large and smaller sharp pointed denticles on the sides of carapace (Figs 7, 9, 17); pedipalpal patella with large and long distal apophysis, with single small denticle at about midpoint (Figs 7, 18); pedipalpal tibia straight across distodorsal end, not notched or otherwise modified in center (Fig. 16). Female epyginum with only slightly rounded lobes posteriorly (Fig. 21); spermathecae elongate and compressed in center (Figs 22, 23).

Description (Briscoe County, specimens illustrated).-Male (Fig. 9): Total length: 2.18 mm; carapace length: 1.05 mm; carapace width (excluding denticles): 0.77 mm; carapace with lateral row of denticles with a small ridge above row (Fig. 7; similar to Hormiga 2000, fig. 86a). Sternum darker brown. Chelicera depressed basally on retrolateral marginal face, with 8 large, distally curved denticles on anteriolateral margins and 10- 12 denticles scattered over promargin basally, also few short thick macrosetae basal to stridulatory file, promargin with 1 mega denticle and 1 large denticle, retromargin with 3 denticles plus 1 smaller distal denticle; cheliceral stridulatory file as large striae on posteriolateral surface (visible with dissection microscope). Cheliceral fang thickened on basal half and with a brush of very fine denticles centrally. Abdomen 1.13 mm long, uniformly colored, no patterns. Legs, tibia I–IV with one dorsal macroseta; metatarsus I with dorsal trichobothrium, TmI 0.43, TmIV 0.52. Pedipalpal femur curved mesally, then dorsally, recurved at distal end (Figs 9, 18), mesal side with longitudinal row of denticles; patella with a thick, stout, apophysis (Figs 7, 18); tibia straight across distodorsal end, not notched or otherwise modified in center, mesal side (about 2/3 from basal end) with raised area tipped with small spur-like point (Fig. 18, 19); embolus thick, straight, pointed at tip (Figs 18, 19); other details of pedipalp as in Fig. 19.

Female: Total length: 2.65 mm, carapace length: 1.05 mm, carapace width: 0.75 mm; carapace coloration as in male, pattern 3 erect setae along midline. Carapace and chelicerae dark amber to yellowish-brown, sternum darker brown; carapace elevated in anterior third; posteriolateral margins of carapace with noticeable small granules to minute denticles; without ridge laterally as in male. Chelicera slightly enlarged basally, with 6-8 denticles in a row on anteriolateral margin; promargin of cheliceral fang furrow with 2 larger and 3 smaller denticles (distal most minute), retromargin with 3 denticles (one distal smaller denticle on each chelicera); stridulatory file not visible with dissection microscope (present as striae on posteriolateral margin at 200 X ). Abdomen unpatterned, darker brown to gray brown, darker than carapace; length 1.60 mm, densely covered with semi-erect setae. Legs light yellow to amber, tibia I–IV each with one dorsal macroseta; metatarsus I with dorsal trichobothrium, TmI 0.57, TmIV absent. Posterior portion of the epigynal plate sclerotized (Fig. 21). Spermathecae only slightly visible through the cuticle and not extending much beyond the epigynal plate (Figs 22, 23). Spermathecae oval and oriented obliquely, fertilization ducts only slightly curved, copulatory ducts long and curved (Fig. 23).

Distribution.-Known from Colorado, Idaho, Montana, Nevada, Oregon, Texas, Utah, and Wyoming in the central and northwestern U.S.A.

Habitat.-In the present study we only found specimens in the canopy of emergent aquatic vegetation within playa wetlands and next to a man-made pond in a wet greenhouse. Levi & Levi (1951) stated that this species was also collected at Moran (Grand Teton National Park, Teton County, Wyoming) from an aspen grove.

Remarks.-In the original description of this species, Chamberlin & Ivie (1939) stated that E. denticulata was related to Erigone ostiaria Crosby & Bishop, but differed by being larger in size and by the details of the pedipalpus. By comparing Crosby & Bishop (1928) figs 149-151 to our Figs 13-15 the pedipalpal differences are apparent. Also, E. ostiaria is thus far only known from Washington State, U.S.A.

In having a mid-position denticle on the pedipalpal patella, this species could be confused with Erigone dentosa O. Pickard-Cambridge (from British Columbia south to Guatemala); however, the denticle on E. dentosa is noticeably larger and distinctly curved distally (Crosby & Bishop 1928, fig. 42). These are not very closely related species, but the denticle is used in the diagnoses presented by Crosby & Bishop (1928).

Crawford (in Buckle et al. 2001 p. 116) stated that this species is probably the same as Erigone aletris Crosby & Bishop. These two species appear similar, especially in the details of the pedipalp in ventral view, but we are able to separate the two taxa. As illustrated by Paquin & Dupérré (2003, figs 958-963) E. aletris differs from E. denticulata in features of the male and female genitalia. Erigone aletris occurs throughout much of the northern Holarctic region and appears to be absent from the plains of the central U.S.A.


Public Domain

MagnoliaPress via Plazi


Belongs to 0 communities

This taxon hasn't been featured in any communities yet.

Learn more about Communities


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!