Torrenticola indistincta (Marshall, 1929)

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 indistincta (Marshall, 1929)

Atractides indistinctus Marshall, 1929: 317.

T. indistincta : Mitchell 1954: 40 • Viets 1956: 253 • Crowell 1960: 35, 37 • Crowell 1961: 330 • Habeeb 1967: 3 • Weaver 1967: 223 • Conroy 1968: 28 • Young 1969: 373-386 • Modlin and Gannon 1973: 219, 221 • Conroy and Scudder 1975: 307.

Material examined.

LECTOTYPE (1 ♀): from USA, Wisconsin, Green Lake County, Green Lake, Aug 1921, by C Juday, RM210013.

PARALECTOTYPE (1 ♂):from USA, Wisconsin, Green Lake County, Green Lake, Aug 1921, by C Juday, RM210013.

OTHER MATERIAL (5 ♀; 4 ♂): Manitoba, Canada: 1 ♂ from Fidler Lake; Station 7., (57°11'11"N, 96°56'56"W), 20 June 1977, by Freshwater Institute, IMS770231 • 1 ♀ from Northern Indian Lake; Station 9., (56°47'47"N, 98°56'56"W), 20 June 1977, by Freshwater Institute, IMS770224 • 1 ♂ from Northern Indian Lake; Station 1., (56°47'47"N, 98°56'56"W), 20 June 1977, by Freshwater Institute, IMS770232 • 1 ♀ from North Pine River near Pine River, 29 May 1981, by P Schefter, E Fuller, ROM810578 • 1 ♀ and 1 ♂ from Southern Indian Lake, (57°10'10"N, 98°29'29"W), 1 July 1977, by Freshwater Institute, IMS770234 • 1 ♀ and 1 ♂ from Southern Indian Lake, (56°47'47"N, 98°56'56"W), 27 July 1977, by Freshwater Institute., IMS770215 • 1 ♀ from Southern Indian Lake, (57°10'10"N, 98°29'29"W), 5 September 1978, by Freshwater Institute., IMS780049

Type deposition.

Types (1 ♀, 1 ♂); and most other material (3 ♀; 2 ♂) deposited in the CNC; other paratypes (2 ♀; 2 ♂) deposited in the ACUA.

Diagnosis.

Torrenticola indistincta are similar to other members of the Rusetria "Eastern 2-Plates" group ( T. biscutella , T. caerulea , T. delicatexa , T. malarkeyorum , T. pendula , T. sellersorum , T. tysoni , T. ululata , T. whitneyae , T. microbiscutella , and T. feminellai ) in having anterio-lateral platelets fused to the dorsal plate, and being distributed in the east. T. indistincta can be differentiated from other Eastern 2-Plates by having faint coloration separated into anterior and posterior portions connected medially. Female T. indistincta can be differentiated from female T. caerulea by having a larger genital field (length = 185-225 in T. indistincta , 155-165 in T. caerulea ; width = 185-205 in T. indistincta , 120-145 in T. caerulea ). Male T. indistincta can be differentiated from male T. caerulea by having a larger dorsum (length = 480-645 in T. indistincta , 405-460 in T. caerulea ; width = 315-470 in T. indistincta , 260-305 in T. caerulea ). T. indistincta can be differentiated from T. microbiscutella by having a less elongate dorsum (length/width = 1.21-1.52 in T. indistincta ; 1.63-1.75 in T. microbiscutella ).

Re-description.

Female (Figure 97) (n = 5) (lectotypic measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (590-880 (640) long; 460-720 (485) wide) ovoid with faint coloration separated into anterior and posterior portions and connected medially. Anterio-medial platelets (125-195 (125) long; 45-77.5 (47.5) wide). Anterio-lateral platelets (172.5-235 (172.5) long; 75-115 (80) wide) fused to dorsal plate. Dgl-4 much closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 340-485 (340)). Dorsal plate proportions: dorsum length/width 1.21-1.32 (1.32); dorsal width/distance between Dgl-4 1.32-1.48 (1.43); anterio-medial platelet length/width 2.35-2.94 (2.63); anterio-lateral platelet length/width 2.02-2.33 (2.16); anterio-lateral/anterio-medial length 1.19-1.38 (1.38).

Gnathosoma - Subcapitulum (300-395 (322.5) long (ventral); 225-295 (237.5) long (dorsal); 145-195 (150) tall) tall and colorless. Rostrum (120-160 (125) long; 45-62.5 (47.5) wide). Chelicerae (300-405 (335) long) with curved fangs (60-80 (62.5) long). Subcapitular proportions: ventral length/height 1.97-2.15 (2.15); rostrum length/width 2.50-2.78 (2.63). Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (45-65 (47.5) long); femur (112.5-160 (117.5) long); genu (62.5-90 (62.5) long); tibia (87.5-122.5 (87.5) long; 25-31.25 (25) wide); tarsus (17.5-30 (17.5) long). Palpomere proportions: femur/genu 1.67-1.88 (1.88); tibia/femur 0.74-0.80 (0.74); tibia length/width 3.50-3.92 (3.50).

Venter - (650-995 (800) long; 535-880 (565) wide) colorless. Gnathosomal bay (175-237.5 (175) long; 90-130 (97.5) wide). Cxgl-4 subapical. Medial suture absent. Genital plates (185-225 (205) long; 185-205 (190) wide). Additional measurements: Cx-1 (295-385 (305) long (total); 120-155 (135) long (medial)); Cx-3 (345-505 (345) wide); anterior venter (125-167.5 (135) long). Ventral proportions: gnathosomal bay length/width 1.79-2.02 (1.79); anterior venter/genital field length 0.66-0.83 (0.66); anterior venter length/genital field width 0.66-0.83 (0.71).

Male (Figure 98) (n = 5) (lectotypic measurements in parentheses when available) with characters of the genus with following specifications.

Dorsum - (480-645 (480) long; 315-470 (315) wide) ovoid with faint coloration separated into anterior and posterior portions and connected medially. Anterio-medial platelets (102.5-147.5 (102.5) long; 35-55 (35) wide). Anterio-lateral platelets (137.5-180 (150) long; 55-82.5 (55) wide) fused to dorsal plate. Dgl-4 much closer to the edge of the dorsum than to the muscle scars (distance between Dgl-4 235-350 (235)). Dorsal plate proportions: dorsum length/width 1.37-1.52 (1.52); dorsal width/distance between Dgl-4 1.31-1.34 (1.34); anterio-medial platelet length/width 2.33-3.05 (2.93); anterio-lateral platelet length/width 2.12-2.73 (2.73); anterio-lateral/anterio-medial length 1.19-1.46 (1.46).

Gnathosoma - Subcapitulum (238.75-317.5 (238.75) long (ventral); 167.5-232.5 (167.5) long (dorsal); 102.5-137.5 (102.5) tall) tall and colorless. Rostrum (85-125 (85) long; 32.5-50 (32.5) wide). Chelicerae (232.5-320 (232.5) long) with curved fangs (47.5-65 (47.5) long). Subcapitular proportions: ventral length/height 2.22-2.33 (2.33); rostrum length/width 2.50-2.86 (2.62). Pedipalps with tuberculate ventral extensions on femora and genua. Palpomeres: trochanter (37.5-52.5 (37.5) long); femur (86.25-117.5 (86.25) long); genu (50-77.5 (50) long); tibia (70-100 (70) long; 22.5-28.75 (22.5) wide); tarsus (17.5-22.5 (17.5) long). Palpomere proportions: femur/genu 1.52-1.73 (1.73); tibia/femur 0.80-0.85 (0.81); tibia length/width 3.11-3.48 (3.11).

Venter - (570-780 (570) long; 370-510 (370) wide) colorless. Gnathosomal bay (127.5-180 (127.5) long; 65-100 (65) wide). Cxgl-4 subapical. Medial suture (65-75 (75) long). Genital plates (117.5-165 (117.5) long; 112.5-150 (112.5) wide). Additional measurements: Cx-1 (235-315 (235) long (total); 107.5-150 (107.5) long (medial)); Cx-3 (250-395 (277.5) wide); anterior venter (190-235 (190) long). Ventral proportions: gnathosomal bay length/width 1.80-1.96 (1.96); anterior venter/genital field length 1.38-1.68 (1.62); anterior venter length/genital field width 1.53-1.69 (1.69); anterior venter/medial suture 2.53-3.54 (2.53).

Immatures unknown.

Etymology.

Marshall (1929) named the specific epithet ( indistincta ) in reference to the Rusetria Complex character of fused ( “indistinct”) lateral platelets.

Distribution.

Midwest and into Manitoba (Figure 96). Young (1969) reported this species from Colorado, but this likely represents T. mulleni rather than T. indistincta .

Remarks.

Unfortunately, we were unable to acquire fresh material of Torrenticola indistincta and therefore this species was not included in our phylogenetic analyses. However, we were able to examine type material and additional material preserved in GAW. The fusion of the lateral platelets to the dorsal plate clearly places this species among the Rusetria Complex and its distribution is consistent with placement within the Eastern 2-Plate Identification Group.

Although Young (1969) reported this species in Colorado, we suspect that record represents the superficially similar T. mulleni based upon distribution.