Neodietrichia hesperia ( Crosby & Bishop, 1933 )

Milne, Marc A., O’Neil, Caylie & Bertaux, James, 2023, A taxonomic revision of Neodietrichia (Araneae: Linyphiidae), a rarely encountered but widespread spider taxon, Zootaxa 5296 (1), pp. 31-44 : 35-36

Neodietrichia hesperia ( Crosby & Bishop, 1933)

( Figs. 2 , 3 , 6 , 7 )

Dietrichia hesperia Crosby & Bishop 1933: 160 , figs. 199–204 (Description of male and female).

Dietrichia hesperia Hackman 1954: 17 , figs. 51–57.

Neodietrichia hesperia Özdikmen 2008: 537 (transferred from Dietrichia ).

Types. Holotype male. U.S.A.: California: 1 male, Madera County, North Fork , 1 March 1920, H. Dietrich ( AMNH ID AMNH _ IZC 00328051 ) . Paratype.— U.S.A.: California: 1 female, same data as holotype [lost, see type data remarks] ;

Type data remarks. Holotype and paratype originally deposited in the collection of Cornell University and then transferred to the American Museum of Natural History. Female paratype not examined, missing from collection, presumed lost during transfer ( Draney 1998).

Diagnosis. Males of N. hesperia differ from N. depressum n. comb. in that the embolus of N. hesperia visibly projects anteriorly behind the protegulum towards the central radical apophysis while in N. depressum n. comb., much of the embolus is not visible but possesses a distal portion that projects ventrally ( Figs. 2B, E , 3A , 4B, E , 5A ). Moreover, the palpal tibial apophysis in N. hesperia is thinner than in N. depressum n. comb. and is relatively straight and flat except for the existence of one to two spines whereas in N. depressum n. comb. it possesses a median keel in addition to smaller distal spines ( Figs. 2C–E , 3C, D , 4C–E , 5C, E, F ). The female epigynum in N. hesperia possesses spermathecae that are directed centrally, underneath the median plate whereas in N. depressum n. comb. they are lateral to the median septum and directed anteriorly. Moreover, the epigynum in N. hesperia possesses a single concave anterior hood whereas in N. depressum n. comb. a dual-lobed concave anterior hood is present ( Figs. 2G, H , 3F, G , 4G, H , 5G, H ).

Description. Male (AMNH_IZC 00328051, holotype; Figs. 2A–E , 3A–E ). Smaller sized (1.38–1.70 total length) erigonines with carapace dusky dark orange to light brown, black around eyes, legs dark yellow in color, and abdomen dark gray to black, often with lighter mottling. Eyes, teeth, pits, anterior and posterior sulci, venter, and spinnerets typical of genus. Chelicerae with 10–13 stridulatory ridges. Clypeus with slight anterior bulge and hairs present. Leg lengths, macrosetae, and claw teeth typical of genus. Metatarsi I–III each with single trichobothrium; metatarsus IV lacking trichobothrium; tibia I–III each with single trichobothrium; tibia IV with 1–3 trichobothria. Pedipalp with large medial radical apophysis that, when viewed ventrally, angles prolaterally and then bends inward distally. Embolus long and extends anteriorly along the retrolateral side of the palp with the point converging near the apex of the radical apophysis. Protegulum extends anteriorly, adjacent to the radical apophysis, but exterior to the distal part of the embolus. Paracymbium small and rounded at the tip ( Figs. 2B, E , 3A ). Palpal tibial apophysis long, thin, straight, and relatively flat with one or two distal or semi-distal spines ( Figs. 2C–E , 3C, D ).

Female (RB, Ohio: Vinton Co.; Figs. 2F–H , 3F, G ). Smaller sized (1.48–1.80) erigonines with coloration of carapace and legs as in male. Abdomen gray as in some of the lighter-colored males. Females lack sulci and pits. Clypeus not bulged and lacking large numbers of clypeal hairs as in male. Eyes, teeth, venter, spinnerets, chelicerae, leg lengths, macrosetae, trichobothria, and claw teeth as in male. Epigynum with single concave anterior hood and dual, ventrally-visible spermathecae. Median plate wide posteriorly and narrows anteriorly. Spermathecae directed centrally, underneath thinner part of median plate. Dual copulatory openings exist medially near narrowing of median plate. Fertilization and copulatory ducts coiled laterally to spermathecae ( Figs. 2H , 3G ).

Measurements. Male: (n=3): Total length, 1.38–1.70 (mean=1.53); carapace length, 0.66–0.76 (mean=0.71); carapace width, 0.51–0.53 (mean=0.52); femur I length, 0.44–0.52 (mean=0.47); TmI (n=2), 0.59–0.63 (mean = 0.61). Female: (n=3): Total length, 1.48–1.8 (mean=1.66); carapace length (n=4), 0.62–0.72 (mean=0.67); carapace width, 0.49–0.53, (mean=0.51); femur I length, 0.42–0.45 (mean=0.44); TmI (n=3), 0.62–0.65 (mean = 0.63).

Variation. The three male specimens that are known all slightly differ in the shape (width and orientation) and number and/or location of spines on the tibial apophysis ( Fig. 6 ). There was no morphological variation seen in the four females examined.

Distribution. Known from only four locations: California (holotype), Maine, Ohio, and Quebec. Likely distributed throughout North America ( Fig. 7 ).

Natural history. Adults have been collected from March - July. Adults have been collected from sweeping lowbush blueberry in agricultural fields, from flight-intercept traps placed 5m up in spruce/fir/hardwood mix forests, under the bark of trees, and from the Berlese extraction of specimens in a broom of Picea mariana .

Other material examined. CANADA: Quebec: Abitibi-Témiscamingue Region, Abitibi-Ouest , coll. P. Paquin and N. Dupérré ( PP, 519), 19–26 June 1994, 1 female ; Eeyou Istchee James Bay Territory, 87 km. N of LaSarre, coll. P. Paquin and N. Dupérré ( PP, 9384), 4 July 1997, 1 female . U.S.A.: Maine: Hancock Co., Bradley Penobscot Experimental Forest , coll. J. Jaros-Su ( MCZ, 104521), 1997, 1 male ; Washington Co., T 30 MD BPP, EBB Survey, coll. J. Crowe ( MCZ, 140958), 20 May 2008, 1 male ; Cocoa Mountain , coll. J. Collins ( MCZ, 151767), 14 May 1993, 1 female . Ohio: Vinton Co., Vinton Furnace near Dundas, coll. M. A. Ivie ( RB), 5 March 1983, 1 female .

Figures

FIGURE 2. Photographs of Neodietrichia hesperia (Male: MCZ 140958, Maine: Washington Co.; Female: RB, Ohio: Vinton Co.). A, Male habitus; B, male left palp, ventral view; C, male left palp, prolateral view; D, male left palp, dorsal view; E, male left palp, retrolateral view; F, female habitus; G, epigynum, ventral view; H, epigynum, cleared dorsal view. Scale bars represent 0.25mm.

FIGURE 3. Illustrations of Neodietrichia hesperia (Male: AMNH_IZC 00328051, holotype; Female: RB, Ohio: Vinton Co.). A, Holotype male left palp, ventral view; B, male carapace, lateral view; C, holotype male left palpal tibial apophysis, retrolateral view; D, holotype male left palp, dorsal view; E, holotype male left palpal embolic division, prolateral view; F, epigynum, ventral view; G, epigynum, cleared dorsal view. R, radix; E, embolus; Pt, protegulum; RA, radical apophysis; T, tegulum; Pc, paracymbium; Su, sulci; H, hood; S, spermathecae; CO, copulatory openings; MP, median plate; CD, copulation ducts; FD, fertilization ducts.

FIGURE 4. Photographs of Neodietrichia depressum n. comb. (MM 6D15, Indiana, Johnson Co.). A, Male habitus; B, male left palp, ventral view; C, male left palp, prolateral view; D, male left palp, dorsal view; E, male left palp, retrolateral view; F, female habitus; G, epigynum, ventral view; H, epigynum, cleared dorsal view. Scale bars represent 0.25mm.

FIGURE 5. Illustrations of Neodietrichia depressum n. comb. (MM 6D15, Indiana, Johnson Co.). A, Male left palp, ventral view; B, male carapace, lateral view; C, male left palpal tibial apophysis, retrolateral view; D, male left palpal embolic division, prolateral view; E, male left palpal tibial apophysis, dorsal view; F, same, variation; G, epigynum, ventral view; H, epigynum, cleared dorsal view. R, radix; E, embolus; Pt, protegulum; RA, radical apophysis; T, tegulum; P, paracymbium; TbA, tibial apophysis; Su, sulci; K, keel; H, hood; S, spermathecae; CO, copulatory openings; MP, median plate; CD, copulation ducts; FD, fertilization ducts.

FIGURE 6. Variation in male palpal tibial apophyses in Neodietrichia hesperia. Illustrations represent retrolateral views.

FIGURE 7. All known collection locations of Neodietrichia. Open circles represent Neodietrichia hesperia. Filled circles represent Neodietrichia depressum n. comb.