Torrenticola larvata Cheri, Fisher, & Dowling, 2016

Fisher, J. Ray, Fisher, Danielle M., Skvarla, Michael J., Nelson, Whitney A. & Dowling, Ashley P. G., 2017, Revision of torrent mites (Parasitengona, Torrenticolidae, Torrenticola) of the United States and Canada: 90 descriptions, molecular phylogenetics, and a key to species, ZooKeys 701, pp. 1-496 : 1

Torrenticola larvata Cheri, Fisher, & Dowling, 2016

Torrenticola larvata Cherri et al. (2016): 246.

Material examined.

HOLOTYPE (♀): USA, Arkansas, Polk Co., Bard Springs, Ouachita National Forest, Blaylock Creek (34°23'28.3"N, 94°00'31.8"W), 11 Aug 2009, by AJ Radwell and BG Crump, AJR090307B.

PARATYPES (5 ♀; 8 ♂): Arkansas, USA: 1 ♂ (ALLOTYPE) from Polk County, Bard Springs, Ouachita National Forest, Blaylock Creek (34°23'28.3"N, 94°00'31.8"W), 11 Aug 2009, by AJ Radwell and BG Crump, AJR090307B • 3 ♀ from Polk County, beside Forest Road 38, North of Shady Lake Rec Area, East Saline Creek (34°22'53.4"N, 94°01'51.2"W), 30 Jul 2011, by IM Smith, IMS110041 • 1 ♀ and 6 ♂ from Montgomery County, Ouachita National Forest, Ouachita River at Mcguire (34°22'53.4"N, 94°1'51.2"W), 27 Aug 2011, by AJ Radwell, AJR110307 • 1 ♀ and 1 ♂ from Garland County, beside Route 7, 3 miles south of Mountain Valley, South Fork of Saline River (34°35'43.3"N, 93°00'45.3"W), 11 May 1977, by DR Cook, DRC770002 • 1 ♂ from Montgomery County, Ouachita National Forest, Ouachita River at Pine Ridge (34°34'53.5"N, 93°53'00.9"W), 5 Oct 2007, by AJ Radwell and HW Robison, AJR070300A.

Type deposition.

Holotype (♀), allotype (♂), and most paratypes (3 ♀; 5 ♂) deposited in the CNC; other paratypes (2 ♀; 3 ♂) deposited in ACUA.

Diagnosis.

Torrenticola larvata are similar to other members of the Tricolor Complex ( T. bittikoferae , T. hoosieri , T. pearsoni , T. olliei , T. sierrensis , T. tricolor , T. trimaculata , T. unimaculata , T. cardia , T. kringi , T. dimorpha , and T. mohawk ) in having a short, conical rostrum. T. larvata can be differentiated from all other Torrenticola , including other members of the Tricolor Complex, by having a distinct dorsal pattern. T. larvata can be further differentiated from T. bittikoferae , T. sierrensis , T. tricolor , T. trimaculata , T. kringi , and T. mohawk by being more elongate (length/width = 1.41-1.57 in T. larvata ; 1.17-1.39 in others); and from T. bittikoferae , T. olliei , T. sierrensis , T. trimaculata , T. unimaculata , T. dimorpha , and T. mohawk by having a more elongate rostrum (length/width = 2.32-2.53 in T. larvata , 1.56-2.27 in others).

Re-description

(amended from Cherri et al. 2016). Female (Figure 127) (n = 6) (holotype measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (650-725 (650) long; 450-475 (460) wide) ovoid and elongate with bluish-purple coloration restricted to the anterio-medial platelets and anterior-most portion of anterio-lateral platelets (rarely continuing to anterior border of the dorsal plate) and to the posterior dorsal plate within the area of primary sclerotization (posterior coloration is sometimes absent) with wide strip of orange medially. Anterio-medial platelets (127.5-132.5 (127.5) long; 175-190 (175) wide). Anterio-lateral platelets (175-190 (175) long; 70-77.5 (70) wide) free from dorsal plate. Dgl-4 much closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 340-375 (340)). Dorsal plate proportions: dorsum length/width 1.41-1.54 (1.41); dorsal width/distance between Dgl-4 1.27-1.35 (1.35); anterio-medial platelet length/width 1.83-2.04 (2.04); anterio-lateral platelet length/width 2.29-2.56 (2.50); anterio-lateral/anterio-medial length 1.37-1.43 (1.37).

Gnathosoma - Subcapitulum (275-287.5 (275) long (ventral); 200-211 (200) long (dorsal); 125-140 (125) tall) with bluish-purple coloration. Rostrum (110-117.5 (112.5) long; 47.5-50 (47.5) wide) short and conical. Chelicerae (260-295 (265) long) with curved fangs (53-62 (60) long). Subcapitular proportions: ventral length/height 2.04-2.25 (2.20); rostrum length/width 2.32-2.42 (2.37). Pedipalps with tuberculate ventral extensions with dentate tips on femora and genua. Palpomeres: trochanter (40-42.5 (40) long); femur (105-107.5 (107.5) long); genu (67.5-72.5 (67.5) long); tibia (87.5-97.5 (90) long; 25-30 (26.25) wide); tarsus (25-27.5 (25) long). Palpomere proportions: femur/genu 1.48-1.59 (1.59); tibia/femur 0.81-0.91 (0.84); tibia length/width 3.25-3.50 (3.43).

Venter - (720-850 (795) long; 525-604 (525) wide) colorless or with bluish-purple coloration, but always with bold bluish-purple on the dorsal coxal area. Gnathosomal bay (117.5-140 (140) long; 77.5-92.5 (77.5) wide). Cxgl-4 subapical. Medial suture (25-35 (35) long). Genital plates (182.5-187.5 (185) long; 145-152.5 (150) wide). Additional measurements: Cx-1 (260-358.5 (260) long (total); 125-183 (125) long (medial)); Cx-3 (307-375 (325) wide); anterior venter (180-195 (180) long). Ventral proportions: gnathosomal bay length/width 1.31-1.81 (1.81); anterior venter/genital field length 0.97-1.04 (0.97); anterior venter length/genital field width 1.20-1.31 (1.20); anterior venter/medial suture 5.14-7.80 (5.14).

Male (Figure 128) (n = 6) (allotypic measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (550-610 (560) long; 350-400 (360) wide) ovoid and elongate with bluish-purple coloration restricted to the anterio-medial platelets and anterior-most portion of anterio-lateral platelets (rarely continuing to anterior border of the dorsal plate) and to the posterior dorsal plate within the area of primary sclerotization (posterior coloration is sometimes absent) with wide strip of orange medially. Anterio-medial platelets (115-120 (120) long; 52.5-65 (55) wide). Anterio-lateral platelets (147.5-162.5 (155) long; 57.5-70 (70) wide) free from dorsal plate. Dgl-4 much closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 285-340 (295)). Dorsal plate proportions: dorsum length/width 1.53-1.57 (1.56); dorsal width/distance between Dgl-4 1.18-1.26 (1.22); anterio-medial platelet length/width 1.85-2.24 (2.18); anterio-lateral platelet length/width 2.21-2.83 (2.21); anterio-lateral/anterio-medial length 1.26-1.41 (1.29).

Gnathosoma - Subcapitulum (230-247.5 (240) long (ventral); 167-182 (175) long (dorsal); 97.5-102.5 (100) tall) with bluish-purple coloration. Rostrum (91.25-100 (93.75) long; 37.5-40 (40) wide) short and conical. Chelicerae (221-239 (225) long) with curved fangs (45-52 (50) long). Subcapitular proportions: ventral length/height 2.30-2.46 (2.40); rostrum length/width 2.34-2.53 (2.34). Pedipalps with tuberculate ventral extensions with dentate tips on femora and genua. Palpomeres: trochanter (32.5-37.5 (35) long); femur (85-95 (90) long); genu (56.25-62.5 (60) long); tibia (75-82.5 (80) long; 23.75-26.25 (25) wide); tarsus (22.5-26.25 (25) long). Palpomere proportions: femur/genu 1.48-1.61 (1.50); tibia/femur 0.82-0.89 (0.89); tibia length/width 3.10-3.20 (3.20).

Venter - (660-710 (680) long; 415-443 (420) wide) colorless or with bluish-purple coloration, but always with bold bluish-purple on the dorsal coxal area. Gnathosomal bay (112.5-130 (125) long; 65-70 (67.5) wide). Cxgl-4 subapical. Medial suture (102.5-125 (110) long). Genital plates (138.75-147.5 (140) long; 97.5-110 (110) wide). Additional measurements: Cx-1 (244-266 (250) long (total); 135-140 (140) long (medial)); Cx-3 (283-305 (295) wide); anterior venter (245-270 (260) long). Ventral proportions: gnathosomal bay length/width 1.67-1.94 (1.85); anterior venter/genital field length 1.77-1.89 (1.86); anterior venter length/genital field width 2.36-2.77 (2.36); anterior venter/medial suture 2.16-2.41 (2.36).

Immatures unknown.

Etymology.

Cherri et al. (2016) named the specific epithet ( larvata ) for the anterior coloration that gives adults a masked appearance (larvat, L. masked).

Distribution.

Ouachita Mountains of Arkansas (Figure 126).

Remarks.

Torrenticola larvata groups with other members of the Tricolor Complex with high support in all analyses and specimens are less than 1% different in COI sequence from each other. In the combined analysis, T. larvata groups with T. dimorpha to form a clade sister to all other eastern members of this complex. These species are greater than 11% from each other. Based upon overall similarity, short conical rostrum, long pedipalp tibiae, phylogenetic position, and distribution, we were able to place this species in the Tricolor Identification Group.

This species hypothesis is supported by low COI divergence within the species (0-2%), high divergence between species (3-15%), and the morphological characters outlined in the diagnosis.