Testudacarus minimus Marshall, 1943

O'Neill, Joseph C., Fisher, J. Ray, Nelson, Whitney A., Skvarla, Micheal J., Fisher, Danielle M. & Dowling, Ashley P. G., 2016, Systematics of testudacarine torrent mites (Acari, Hydrachnidia, Torrenticolidae) with descriptions of 13 new species from North America, ZooKeys 582, pp. 13-110 : 27-32

Taxon classification Animalia Trombidiformes Torrenticolidae

Testudacarus minimus Marshall, 1943

Testudacarus minimus : Marshall 1943: 322; Bergstrom 1953: 159; Mitchell 1954: 40; Imamura 1955: 182, 188; Viets 1956: 255; Habeeb 1959a: 21; Crowell 1961: 329; Mitchell 1962: 42; Lundblad 1967: 418; Conroy 1968: 29; Habeeb 1974a: 1; Conroy and Scudder 1975: 307; Imamura 1976: 283; Viets 1987: 724-725; Smith et al. 2011: 262.

Testudacarus americanus : Habeeb 1967: 1.

Testudacarus americanus minimus : Habeeb 1969: 2.

Type series.

Holotype (1♂): California, USA: 1♂ from Santa Cruz County, Waddell Creek, 30-31 August 1933, by PR Needham, RM330016.

Other material examined.

Other (15♀, 15♂): Montana, USA: 2♂ from Ravalli County, Bitterroot National Forest, Lost Horse River, downstream of confluence of North Lost Horse (45°7'7.00"N, 114°18'0.00"W), 3 August 2012, by JR Fisher and WA Nelson, ROW12-0803-006; 1♂ from Powell County, Monture Creek, at fishing access off Highway 200 west of Ovando (47°2'15.00"N, 112°13'12.00"W), 9 August 2012, by AJ Radwell and JA Hinsey, AJR12-0809-415A; Washington, USA: 2♂ from Snohomish County, Mount Baker National Forest, Clean Creek, (48°13'8.00"N, 121°34'7.00"W), 28 July 2013, by JC O’Neill and WA Nelson, JNOW13-0728-007; 2♀ from Jefferson County, Olympic National Forest, Snow Creek, (47°56'11.00"N, 122°56'53.00"W), 22 July 2013, by WA Nelson and JC O’Neill, JNOW13-0722-001; 2♀ from Grays Harbor County, Capitol State Forest, Porter Creek, (46°58'13.00"N, 123°16'2.00"W), 25 July 2013, JC O’Neill and WA Nelson, JNOW13-0725-005; 1♀ from Skamania County, Gifford Pinchot National Forest, Lewis Creek, (46°7'40.00"N, 121°59'24.00"W), 1 August 2013, by JC O’Neill and WA Nelson, JNOW13-0801-004; California, USA: 1♂ from Inyo County, Inyo National Forest, Bishop Creek, downstream of campground (37°17'23.00"N, 118°33'14.00"W), 2 September 2013, by JR Fisher, JRF13-0902-003; 2♀ from Nevada County, Tahoe National Forest, Sagehen Creek, off Route 89 (39°26'2.00"N, 120°12'17.00"W), 26 August 2013, by JR Fisher, JRF13-0826-006; 1♀ from Siskiyou County, Klamath National Forest, Shadow Creek, off Cecilville Road, (41°12'13.00"N, 123°4'18.00"W), 17 August 2013, by JR Fisher, JRF13-0817-002; Wyoming, USA: 1♂ from Albany County, North Fork of Little Laramie River, at bridge on Highway 130 (41°19'42.00"N, 106°9'42.00"W), 3 August 2012, by AJ Radwell and JA Hinsey, AJR12-0803-406; 2♂ from Albany County, South Clear Creek, across from Southfork Campground on Highway 16 (44°16'36.00"N, 106°57'4.00"W), 14 August 2012, by AJ Radwell and JA Hinsey, AJR12-0814-419; 1♀ from Fremont County, Wind River, off County Road 773 30 miles east of Moran on Highway 26/287 (43°43'5.00"N, 110°48'0.00"W), 5 August 2012, by AJ Radwell and JA Hinsey, AJR12-0805-410; Utah, USA: 2♂ from Cache County, Wasatch-Cache National Forest, Jordan River, (41°44'33.00"N, 111°45'57.00"W), 24 July 2012, by JR Fisher and WA Nelson, ROW12-0724-004; Idaho, USA: 2♂ from Blaine County, Sawtooth National Forest, Baker Creek, (43°45'28.00"N, 114°33'44.00"W), 28 July 2012, by JR Fisher and WA Nelson, ROW12-0728-001; 2♂ from Lemhi County, Salmon National Forest, Niapas Creek at confluence with Panther Creek, (45°8'15.00"N, 114°13'4.00"W), 2 August 2012, by JR Fisher and WA Nelson, ROW12-0802-003; Colorado, USA: 1♀ from Gunnison County, Quartz Creek, north of Ohio City on County Road 76 mile marker 11 (38°34'2.00"N, 106°34'6.00"W), 1 August 2012, by AJ Radwell and JA Hinsey, AJR12-0801-403A; Oregon, USA: 1♀ from Tillamook County, Siuslaw National Forest, Alder Creek, (45°9'27.00"N, 123°47'60.00"W), 6 August 2013, by JC O’Neill, JNOW13-0806-002; 1♀ from Lane County, Gate Creek, (44°8'48.00"N, 122°34'20.00"W), 11 August 2013, by JC O’Neill and WA Nelson, JNOW 13-0811-001; 1♀ from Curry County, Rogue River National Forest, Elk River, off National Forest Road 5325 (42°42'46.00"N, 124°18'41.00"W), 13 August 2013, by JR Fisher, JRF13-0813-003; Arizona, USA: 1♀ from Cochise County, Chirichua Mountains west of Portal, East Turkey Creek, off Forest Road 42 above junction with Forest Road 42B (31°54'32.00"N, 109°15'11.00"W), 15 May 2011, by IM Smith, IMS110003; 1♀ from Cochise County, Chiricahua Mountains west of Portal, East Turkey Creek, off Forest Road 42 just above junction with Forest Road 42B (31°54'32.00"N, 109°15'11.00"W), 15 May 2011, by IM Smith, IMS110004.

Type deposition.

Holotype (1♂) deposited at the CNC.

Diagnosis.

Testudacarus minimus most resemble Testudacarus vulgaris and Testudacarus deceptivus . Throughout the majority of their shared range in the west, Testudacarus minimus are orange to red and Testudacarus vulgaris are violet to blue. While these two species have overlapping size ranges, Testudacarus minimus are generally larger. Testudacarus vulgaris females rarely exhibit a dorsal length over 600 µm and males rarely exceed 500 µm while Testudacarus minimus females and males are usually larger than 600 and 500 µm, respectively. Testudacarus deceptivus have only been found in two counties in California and cannot be distinguished from either Testudacarus minimus or Testudacarus vulgaris using morphology. Testudacarus minimus are the only members of their complex that have been found in Washington and northern Oregon.

Redescription.

Female (n=14) with characteristics of the genus with following specifications.

Gnathosoma - Subcapitulum [154-173 ventral length; 96-108 dorsal length; 90-105 tall] elliptic to ovoid with short rostrum. Chelicerae [133-152 long] unmodified with slightly curved fangs [29-32 long]. Pedipalp [181-202 long] unmodified. Trochanter [25-30 long; 30-35 wide]. Femur [49-58 long; 38-42 wide]. Genu [38-42 long; 32-35 wide]. Tibia [45-52 long; 22-25 wide]. Tarsus [19-23 long; 9-12 wide].

Dorsum (Fig. 13) - [571-699 long; 442-533 wide] round to ovoid. Dorsal plate [464-591 long; 375-457 wide]. Primary sclerotization [405-467 long] color variable (Fig. 14). Dorso-glandularia-4 [190-250 apart] in line with and lateral to [51-71] muscle scars. Platelets mostly colorless but with hints of primary sclerotization color. All three anterior platelets with color either completely absent or present proximally but restricted distally. Anterio-medial platelet [115-139 long; 73-86 wide] rounded trapezoid noticeably smaller than anterio-lateral platelets [161-190 long; 65-86 wide]. Lateral platelets as follows: lateral-1 [42-63 long; 28-43 wide]; lateral-2 [120-148 long; 24-36 wide]; lateral-3 [32-46 long; 16-24 wide]; lateral-4 [91-138 long; 22-32 wide]; lateral-5 [41-68 long; 21-37 wide]; lateral-6 [76-117 long; 19-41 wide]; lateral-7 [49-78 long; 19-34 wide].

Venter (Fig. 13) - [731-865 long; 466-556 wide] round to ovoid. Primary sclerotization [566-658 long] usually with dorsal plate color or colorless. Gnathosomal bay [54-82 dorsal length; 122-158 ventral length; 49-65 wide]. Coxal field [434-495 long; 303-366 wide]. Coxa-I [231-261 long; 94-111 midlength]. Coxa-II + III [105-127 distance to top of coxa-II; 171-201 distance to top of coxa-III; 312-362 distance to bottom of coxa-III; 201-242 total length]. Coxa-IV [434-495 distance to top; 132-155 total length]. Genital field [288-340 distance to top; 450-512 distance to bottom; 142-183 total length; 124-150 width; 164-184 distance from gnathosomal bay; 57-81 distance from coxa-I; 182-226 distance to excretory pore; 276-353 distance to caudad]. Eggs [130-135 long; 1-4 eggs]. Distance to excretory pore [637-737].

Legs - colorless, or with same color as dorsal plate. Total leg and podomere lengths as follows: Leg-I [428-477 total; trochanter 48-55; basifemur 72-85; telofemur 60-69; genu 78-90; tibia 83-95; tarsus 79-92]. Leg-II [453-530 total; trochanter 54-62; basifemur 74-87; telofemur 58-68; genu 83-96; tibia 96-110; tarsus 99-113]. Leg-III [440-625 total; trochanter 55-65; basifemur 76-88; telofemur 64-76; genu 106-117; tibia 120-137; tarsus 131-148]. Leg-IV [677-843 total; trochanter 87-97; basifemur 106-120; telofemur 111-122; genu 146-160; tibia 160-173; tarsus 147-180].

Male (n=16) similar to female except for sexually dimorphic characters previously discussed and with following specifications.

Gnathosoma - Subcapitulum [138-164 ventral length; 88-105 dorsal length; 83-93 tall]. Chelicerae [120-145 long]. Fangs [27-30 long]. Pedipalp [181-206 long]. Trochanter [24-32 long; 28-33 wide]. Femur [48-59 long; 35-40 wide]. Genu [38-46 long; 29-34 wide]. Tibia [43-54 long; 19-25 wide]. Tarsus [16-22 long; 9-12 wide].

Dorsum (Fig. 15) - [486-549 long; 356-417 wide]. Dorsal plate [406-470 long; 315-372 wide]. Dorso-glandularia-4 [141-219 apart] slightly anterior to [15-52] and well lateral to [31-64] muscle scars. Anterio-medial platelet [99-129 long; 63-80 wide]. Anterio-lateral platelets [151-179 long; 59-76 wide]. Lateral platelets as follows: lateral-1 [31-46 long; 23-32 wide]; lateral-2 [99-124 long; 20-28 wide]; lateral-3 [34-48 long; 14-23 wide]; lateral-4 [65-97 long; 17-28 wide]; lateral-5 [39-56 long; 15-27 wide]; lateral-6 [51-69 long; 17-28 wide]; lateral-7 [42-56 long; 18-28 wide].

Venter (Fig. 15) - [596-717 long; 379-457 wide]. Primary sclerotization [564-650 long]. Gnathosomal bay [53-68 dorsal length; 120-150 ventral length; 51-63 wide]. Coxal field [412-480 long; 290-329 wide]. Coxa-I [215-249 long; 83-105 midlength]. Coxa-II + III [95-115 distance to top of coxa-II; 158-191 distance to top of coxa-III; 329-380 distance to bottom of coxa-III; 230-265 total length]. Coxa-IV [293-328 length to top; 119-153 total length]. Genital field [357-406 distance to top; 493-569 distance to bottom; 129-164 total length; 114-127 width; 228-258 distance from gnathosomal bay; 128-160 distance from coxa-I; 63-91 distance to excretory pore; 101-154 distance to caudad]. Genital skeleton [190-215 long; 93-109 wide]. Distance to excretory pore [564-650].

Legs - total leg and podomere lengths as follows: Leg-I [435-483 total; trochanter 53-63; basifemur 75-84; telofemur 57-69; genu 78-89; tibia 82-93; tarsus 80-90]. Leg-II [458-518 total; trochanter 52-64; basifemur 75-87; telofemur 59-69; genu 79-90; tibia 92-104; tarsus 96-109]. Leg-III [530-599 total; trochanter 54-62; basifemur 75-88; telofemur 63-72; genu 97-111; tibia 114-133; tarsus 124-137]. Leg-IV [722-813 total; trochanter 81-95; basifemur 102-122; telofemur 103-118; genu 130-159; tibia 150-167; tarsus 145-158].

Distribution.

Abundant throughout North America, ranging from the Pacific Northwest to the southwestern United States (and potentially into northern Mexico), and east into the western Great Plains.

Remarks.

Commonly colorless or orange in the southwestern United States; red, pink, or orange–red in the northwest, Rocky Mountains, and western Great Plains; and uncommonly red–violent in the northwest, Rocky Mountains, and western Great Plains.