Torrenticola nortoni Fisher & Dowling

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 nortoni Fisher & Dowling sp. n.

Material examined.

HOLOTYPE (♀): from USA, California, Trinity County, Shasta-Trinity National Forest, Wilson Creek (40°25'17"N, 123°3'5"W), 20 Aug 2013, by JR Fisher, JRF 13-0820-003, DNA 3000.

PARATYPES (9 ♀; 5 ♂): California, USA: 1 ♂ (ALLOTYPE) from USA, California, Trinity County, Shasta-Trinity National Forest, Wilson Creek (40°25'17"N, 123°3'5"W), 20 Aug 2013, by JR Fisher, JRF 13-0820-003, DNA 2996 • 5 ♀ and 2 ♂ from Plumas County, Plumas National Forest, Silver Creek (39°56'60"N, 121°2'17"W), 24 Aug 2013, by JR Fisher, JRF 13-0824-005 • 3 ♀ and 1 ♂ from Trinity County, Shasta-Trinity National Forest, Wilson Creek (40°25'17"N, 123°3'5"W), 20 Aug 2013, by JR Fisher, JRF 13-0820-003 • 1 ♀ and 1 ♂ from Tulare County, Sequoia National Forest, Brush Creek (35°57'57"N, 118°28'43"W), 3 Sep 2013, by JR Fisher, JRF 13-0903-002.

Type deposition.

Holotype (♀), allotype (♂), and some paratypes (5 ♀; 2 ♂) deposited in the CNC; other paratypes (4 ♀; 2 ♂) deposited in ACUA.

Diagnosis.

Torrenticola nortoni are similar to other members of the Rusetria "Western 2-Plates" group ( T. mulleni , T. walteri , and T. welbourni ) in having anterio-lateral platelets fused to the dorsal plate, having faint dorsal coloration (some are colorless), and being distributed in the west. Female T. nortoni can be differentiated from T. welbourni (female only known) by having stockier pedipalp tibiae (3.13-3.33 in A33, 3.73 in A30) and shorter pedipalp femora (112.5-122.5 in A33, 137.5 in A30). Female T. nortoni can be differentiated from female T. mulleni by having a shorter medial suture (10-12.5 in A33; 20-22.5 in A31) and a shorter genital field (177.5-192.5 in A33, 195-205 in A31). Male T. nortoni can be differentiated from male T. mulleni by having shorter pedipalp femora (85-93 in T. nortoni , 97-103 in T. mulleni ). Additionally, T. nortoni can be differentiated from T. mulleni by being distributed in California, instead of in the Rocky Mountains (Idaho, Montana, Utah and Wyoming). Female T. nortoni can be differentiated from female T. walteri by having slightly longer pedipalp femora with respect to genua (1.69-1.82 in T. nortoni , 1.52-1.64 in T. walteri ) and slightly more elongate anterio-medial platelets (2.74-3.06 in T. nortoni , 2.58-2.72 in T. walteri ). Male T. nortoni can be differentiated from male T. walteri by having longer pedipalp femora (85-92.5 in T. nortoni , 95-100 in T. walteri ) and slightly more elongate pedipalp tibiae (2.73-3.0 in T. nortoni , 3.05-3.10 in T. walteri ).

Description.

Female (Figure 168) (n = 5) (holotype measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (570-645 (580) long; 420-480 (435) wide) ovoid with faint orange coloration or colorless. Anterio-medial platelets (122.5-131.25 (125) long; 40-47.5 (42.5) wide). Anterio-lateral platelets (155-180 (162.5) long; 50-57.5 (57.5) wide) fused to dorsal plate. Dgl-4 closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 295-320 (310)). Dorsal plate proportions: dorsum length/width 1.31-1.36 (1.33); dorsal width/distance between Dgl-4 1.40-1.50 (1.40); anterio-medial platelet length/width 2.74-3.06 (2.94); anterio-lateral platelet length/width 2.83-3.20 (2.83); anterio-lateral/anterio-medial length 1.22-1.38 (1.30).

Gnathosoma - Subcapitulum (310-330 (325) long (ventral); 232.5-243.25 (240) long (dorsal); 132.5-140 (132.5) tall) colorless. Rostrum (125-130 (130) long; 43.75-50 (45) wide). Chelicerae (315-325 (325) long) with curved fangs (60-66 (60) long). Subcapitular proportions: ventral length/height 2.34-2.45 (2.45); rostrum length/width 2.60-2.89 (2.89). Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (45-50 (45) long); femur (112.5-122.5 (120) long); genu (62.5-72.5 (70) long); tibia (80-90 87.5) long; 25-28.75 (26.25) wide); tarsus (17.5-20 (17.5) long). Palpomere proportions: femur/genu 1.69-1.82 (1.71); tibia/femur 0.71-0.73 (0.73); tibia length/width 3.13-3.33 (3.33).

Venter - (710-760 (730) long; 470-560 (490) wide) colorless. Gnathosomal bay (152.5-167.5 (167.5) long; 81.25-95 (85) wide). Cxgl-4 subapical. Medial suture (10-12.5 (12.5) long). Genital plates (177.5-192.5 (182.5) long; 160-182.5 (160) wide). Additional measurements: Cx-1 (270-281 (280) long (total); 110-124 (110) long (medial)); Cx-3 (300-365 (320) wide); anterior venter (157.5-177.5 (157.5) long). Ventral proportions: gnathosomal bay length/width 1.61-1.97 (1.97); anterior venter/genital field length 0.86-0.92 (0.86); anterior venter length/genital field width 0.97-0.98 (0.98); anterior venter/medial suture 12.6-17.75 (12.6).

Male (Figure 169) (n = 5) (allotypic measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (450-500 (455) long; 310-380 (320) wide) ovoid with faint orange coloration or colorless. Anterio-medial platelets (97.5-105 (102.5) long; 35-37.5 (37.5) wide). Anterio-lateral platelets (127.5-145 (137.5) long; 45-53.75 (45) wide) fused to dorsal plate. Dgl-4 closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 240-285 (245)). Dorsal plate proportions: dorsum length/width 1.32-1.45 (1.42); dorsal width/distance between Dgl-4 1.29-1.37 (1.31); anterio-medial platelet length/width 2.67-2.80 (2.73); anterio-lateral platelet length/width 2.60-3.06 (3.06); anterio-lateral/anterio-medial length 1.28-1.44 (1.34).

Gnathosoma - Subcapitulum (250-267.5 (252.5) long (ventral); 180-195 (192.5) long (dorsal); 95-107.5 (97.5) tall) colorless. Rostrum (97.5-105 (105) long; 35-37.5 (37.5) wide). Chelicerae (246-260 (250) long) with curved fangs (45-52 (50) long). Subcapitular proportions: ventral length/height 2.49-2.63 (2.59); rostrum length/width 2.67-2.80 (2.80). Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (35-42.5 (37.5) long); femur (85-92.5 (92.5) long); genu (52.5-60 (56.25) long); tibia (66.25-75 (67.5) long; 22.5-27.5 (22.5) wide); tarsus (15-17.5 (17.5) long). Palpomere proportions: femur/genu 1.54-1.64 (1.64); tibia/femur 0.73-0.81 (0.73); tibia length/width 2.73-3.00 (3.00).

Venter - (560-620 (590) long; 350-431 (370) wide) colorless. Gnathosomal bay (106-128 (122.5) long; 65-67.5 (65) wide). Cxgl-4 subapical. Medial suture (82.5-110 (102.5) long). Genital plates (112.5-125 (115) long; 90-102.5 (90) wide). Additional measurements: Cx-1 (211-230 (230) long (total); 100-110 (110) long (medial)); Cx-3 (260-292 (270) wide); anterior venter (232.5-250 (240) long). Ventral proportions: gnathosomal bay length/width 1.60-1.89 (1.88); anterior venter/genital field length 1.96-2.13 (2.09); anterior venter length/genital field width 2.39-2.67 (2.67); anterior venter/medial suture 2.18-2.82 (2.34).

Immatures unknown.

Etymology.

Specific epithet ( nortoni ) named in honor of acarologist Roy Norton who taught JRF oribatids during the Soil Mite Course at The Ohio State University Acarology Summer Program; specifically for his talent in weaving biological stories into his lessons.

Distribution.

California (Figure 167).

Remarks.

Torrenticola nortoni groups with other members of the Rusetria Complex with high support and specimens are less than 2% different in COI sequence from each other. In the all analyses, T. mulleni groups with the three other members of the Rusetria Complex that are found in western North America: T. mulleni , T. walteri , and T. welbourni . These species are 5-7% different in COI sequence from each other and together make up the Western 2-Plate Identification Group. Torrenticola nortoni is one of three of these that occur in California (including T. walteri and T. welbourni ).

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